The effects of climate change impact the physical environment,

ecosystems An ecosystem (or ecological system) consists of all the organisms and the physical environment with which they interact. These biotic and abiotic components are linked together through nutrient cycles and energy flows. Energy enters the syst ...

and human societies. The environmental effects of climate change are broad and far-reaching. They affect the

water cycle The water cycle, also known as the hydrologic cycle or the hydrological cycle, is a biogeochemical cycle that describes the continuous movement of water on, above and below the surface of the Earth. The mass of water on Earth remains fairly cons ...

oceans The ocean (also the sea or the world ocean) is the body of salt water that covers approximately 70.8% of the surface of Earth and contains 97% of Earth's water. An ocean can also refer to any of the large bodies of water into which the worl ...

, sea and land ice ( glaciers),

sea level Mean sea level (MSL, often shortened to sea level) is an average surface level of one or more among Earth's coastal bodies of water from which heights such as elevation may be measured. The global MSL is a type of vertical datuma standardise ...

, as well as weather and climate extreme events. The changes in climate are not uniform across the Earth. In particular, most land areas have warmed faster than most ocean areas, and the

Arctic The Arctic ( or ) is a polar region located at the northernmost part of Earth. The Arctic consists of the Arctic Ocean, adjacent seas, and parts of Canada (Yukon, Northwest Territories, Nunavut), Danish Realm (Greenland), Finland, Iceland, N ...

is warming faster than most other regions. The regional changes vary: at high latitudes it is the average temperature that is increasing, while for the oceans and tropics it is in particular the rainfall and the

where changes are observed. The magnitude of future impacts of

climate change In common usage, climate change describes global warming—the ongoing increase in global average temperature—and its effects on Earth's climate system. Climate change in a broader sense also includes previous long-term changes to ...

can be reduced by climate change mitigation and adaptation. Climate change has

degraded land Land degradation is a process in which the value of the biophysical environment is affected by a combination of human-induced processes acting upon the land. It is viewed as any change or disturbance to the land perceived to be deleterious o ...

by raising temperatures, drying soils and increasing

wildfire A wildfire, forest fire, bushfire, wildland fire or rural fire is an unplanned, uncontrolled and unpredictable fire in an area of combustible vegetation. Depending on the type of vegetation present, a wildfire may be more specifically identi ...

risk. Recent warming has strongly affected natural biological systems. Species worldwide are migrating poleward to colder areas. On land, many species move to higher elevations, whereas marine species seek colder water at greater depths. Between 1% and 50% of species on land were assessed to be at substantially higher risk of

extinction Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...

due to climate change. Among the effects of climate change on oceans are: an increase in

sea surface temperature Sea surface temperature (SST), or ocean surface temperature, is the ocean temperature close to the surface. The exact meaning of ''surface'' varies according to the measurement method used, but it is between and below the sea surface. Air mas ...

as well as ocean temperatures at greater depths, more frequent marine heatwaves, a reduction in pH value, a rise in sea level from ocean warming and

ice Ice is water frozen into a solid state, typically forming at or below temperatures of 0 degrees Celsius or Depending on the presence of impurities such as particles of soil or bubbles of air, it can appear transparent or a more or less opaqu ...

sheet melting, sea ice decline in the Arctic, increased upper

ocean stratification Stratification is the separation of water in layers. Two main types of stratification of water are uniform and layered stratification. Layered stratification occurs in all ocean basins. Stratified layers act as a barrier to the mixing of water, whi ...

, reductions in oxygen levels, increased contrasts in salinity (salty areas becoming saltier and fresher areas becoming less salty), changes to

ocean currents An ocean current is a continuous, directed movement of sea water generated by a number of forces acting upon the water, including wind, the Coriolis effect, breaking waves, cabbeling, and temperature and salinity differences. Depth contour ...

including a weakening of the

Atlantic meridional overturning circulation The Atlantic meridional overturning circulation (AMOC) is part of a global thermohaline circulation in the oceans and is the zonally integrated component of surface and deep currents in the Atlantic Ocean. It is characterized by a northward fl ...

, and stronger

tropical cyclones A tropical cyclone is a rapidly rotating storm system characterized by a low-pressure center, a closed low-level atmospheric circulation, strong winds, and a spiral arrangement of thunderstorms that produce heavy rain and squalls. Dependi ...

and

monsoons A monsoon () is traditionally a seasonal reversing wind accompanied by corresponding changes in precipitation but is now used to describe seasonal changes in atmospheric circulation and precipitation associated with annual latitudinal oscill ...

. The uptake of carbon dioxide from the atmosphere is leading to

ocean acidification Ocean acidification is the reduction in the pH value of the Earth’s ocean. Between 1751 and 2021, the average pH value of the ocean surface has decreased from approximately 8.25 to 8.14. The root cause of ocean acidification is carbon dioxid ...

. All these changes have knock-on effects which disturb

marine ecosystems Marine ecosystems are the largest of Earth's aquatic ecosystems and exist in waters that have a high salt content. These systems contrast with freshwater ecosystems, which have a lower salt content. Marine waters cover more than 70% of the su ...

Food security Food security speaks to the availability of food in a country (or geography) and the ability of individuals within that country (geography) to access, afford, and source adequate foodstuffs. According to the United Nations' Committee on World ...

and access to fresh water are at risk due to rising temperatures. Climate change has profound impacts on human health, directly via heat stress and indirectly via the spread of infectious diseases. The vulnerability and exposure of humans to climate change varies by

economic sector One classical breakdown of economic activity distinguishes three sectors: * Primary: involves the retrieval and production of raw-material commodities, such as corn, coal, wood or iron. Miners, farmers and fishermen are all workers in the ...

and by country. Wealthy industrialised countries, which have emitted the most CO₂, have more resources and so are the least vulnerable to global warming. Economic sectors that are likely to be affected include

agriculture Agriculture or farming is the practice of cultivating plants and livestock. Agriculture was the key development in the rise of sedentary human civilization, whereby farming of domesticated species created food surpluses that enabled people t ...

, fisheries,

forestry Forestry is the science and craft of creating, managing, planting, using, conserving and repairing forests, woodlands, and associated resources for human and environmental benefits. Forestry is practiced in plantations and natural stands. ...

energy In physics, energy (from Ancient Greek: ἐνέργεια, ''enérgeia'', “activity”) is the quantitative property that is transferred to a body or to a physical system, recognizable in the performance of work and in the form of hea ...

insurance Insurance is a means of protection from financial loss in which, in exchange for a fee, a party agrees to compensate another party in the event of a certain loss, damage, or injury. It is a form of risk management, primarily used to hedge ...

, financial services,

tourism Tourism is travel for pleasure or business; also the theory and practice of touring, the business of attracting, accommodating, and entertaining tourists, and the business of operating tours. The World Tourism Organization defines tourism mor ...

, and recreation. Some groups may be particularly at risk from climate change, such as the poor,

women A woman is an adult female human. Prior to adulthood, a female human is referred to as a girl (a female child or adolescent). The plural ''women'' is sometimes used in certain phrases such as "women's rights" to denote female humans regardl ...

, children and

indigenous peoples Indigenous peoples are culturally distinct ethnic groups whose members are directly descended from the earliest known inhabitants of a particular geographic region and, to some extent, maintain the language and culture of those original people ...

. They also have much lower levels of capacity for coping with the effects of environmental change. Climate change can result in

environmental migration Environmental migrants are people who are forced to leave their home region due to sudden or long-term changes to their local or regional environment. These changes compromise their well-being or livelihood, and include increased drought, deserti ...

, especially in developing countries where people are directly dependent on land for food. Even if global surface temperature is stabilized, sea levels will continue to rise and the ocean will continue to absorb excess heat from the atmosphere for many centuries.

Observed and future changes in temperature

Change in Average Temperature With Fahrenheit

Global warming affects all elements of Earth's

climate system Earth's climate system is a complex system having five interacting components: the atmosphere (air), the hydrosphere (water), the cryosphere (ice and permafrost), the lithosphere (earth's upper rocky layer) and the biosphere (living things). '' ...

. Global surface temperatures have risen by 1 °C and are expected to rise further in the future.IPCC, 2013
Summary for Policymakers.
In: Climate Change 2013: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change p.20 Night-time temperatures have increased faster than daytime temperatures. The impact on the environment, wildlife, society and humanity depends on how much more the Earth warms., in . One of the methods scientists use to predict the effects of human-caused climate change is to investigate past natural changes in climate. To assess changes in Earth's past climate scientists have studied tree rings, ice cores,

coral Corals are marine invertebrates within the class Anthozoa of the phylum Cnidaria. They typically form compact colonies of many identical individual polyps. Coral species include the important reef builders that inhabit tropical oceans and ...

s, and ocean and lake sediments. These show that recent warming has surpassed anything in the last 2,000 years.The 20th century was the hottest in nearly 2,000 years, studies show
, 25 July 2019 By the end of the 21st century, temperatures may increase to a level not experienced since the mid-

Pliocene The Pliocene ( ; also Pleiocene) is the epoch in the geologic time scale that extends from 5.333 million to 2.58 At that time, mean global temperatures were about 2–4 °C warmer than pre-industrial temperatures, and the global mean sea level was up to 25 meters higher than it is today.How much the world warms depends on what humans do or not to limit GHG emissions, and how sensitive the climate is to greenhouse gases. Scientists are pretty sure that with double the amount of GHG in the atmosphere the world would warm by 2.5 °C to 4 °C; but how much more humans will emit is less certain. The projected magnitude of warming by 2100 is closely related to the level of cumulative emissions over the 21st century (total emissions between 2000 and 2100). The higher the cumulative emissions over this time period, the greater the level of warming is projected to occur. , p.28. This publication is also available i
e-book format
If emissions of were to be abruptly stopped and no

negative emission technologies Carbon dioxide removal (CDR), also known as negative emissions, is a process in which carbon dioxide gas () is removed from the atmosphere and sequestered for long periods of time. Similarly, greenhouse gas removal (GGR) or negative greenho ...

deployed, the Earth's climate would not start moving back to its pre-industrial state. Instead, temperatures would stay elevated at the same level for several centuries. After about a thousand years, 20% to 30% of human-emitted will remain in the atmosphere, not taken up by the ocean or the land, committing the climate to a warmer state long after emissions have stopped.

Weather-related changes

The lower and middle atmosphere, where nearly all of the weather occurs, are heating due to the enhanced

greenhouse effect The greenhouse effect is a process that occurs when energy from a planet's host star goes through the planet's atmosphere and heats the planet's surface, but greenhouse gases in the atmosphere prevent some of the heat from returning directly ...

. Increased greenhouse gases cause the higher parts of the atmosphere, the stratosphere, to cool. The heated atmosphere contains more

water vapour (99.9839 °C) , - , Boiling point , , - , specific gas constant , 461.5 J/( kg·K) , - , Heat of vaporization , 2.27 MJ/kg , - , Heat capacity , 1.864 kJ/(kg·K) Water vapor, water vapour or aqueous vapor is the gaseous pha ...

, which is also a greenhouse gas and acts as a self-reinforcing feedback. As temperatures increase, so does evaporation and atmospheric moisture content that increases heating by trapping outgoing radiation. Excess water vapour gets caught up in storms and makes them more intense, larger, and potentially longer lasting, so that rain and snow events are stronger and increase risk of flooding. Extra drying worsens any natural dry spells and droughts, and increases risk of heat waves and wildfires. Climate change makes many aspects of weather more extreme, especially heat waves, drought, rain intensity, and storm size and intensity.. Global warming leads to an increase in

extreme weather Extreme weather or extreme climate events includes unexpected, unusual, severe, or unseasonal weather; weather at the extremes of the historical distribution—the range that has been seen in the past. Often, extreme events are based on a loca ...

events such as heat waves, droughts, cyclones, blizzards and rainstorms., in . Such events will continue to occur more often and with greater intensity.

Extreme event attribution Extreme event attribution, also known as attribution science, is a relatively new field of study in meteorology and climate science that tries to measure how ongoing climate change directly affects recent extreme weather events. Attribution scien ...

, also known as attribution science, is a field of study in

meteorology Meteorology is a branch of the atmospheric sciences (which include atmospheric chemistry and physics) with a major focus on weather forecasting. The study of meteorology dates back millennia, though significant progress in meteorology did no ...

and

climate science Climatology (from Greek , ''klima'', "place, zone"; and , '' -logia'') or climate science is the scientific study of Earth's climate, typically defined as weather conditions averaged over a period of at least 30 years. This modern field of stu ...

that tries to measure how ongoing

directly affects recent

events.

Rain and snow

Warming by greenhouse gas forcing has increased contrasts in rainfall amounts between wet and dry seasons, meaning "wet seasons are getting wetter, dry seasons are getting drier". Over oceans, salty areas are getting saltier and other regions are becoming less saline. Warming has also resulted in a detectable increase in the precipitation of northern high latitudes. Higher temperatures lead to increased evaporation and surface drying. As the air warms, its water-holding capacity also increases, particularly over the oceans. Air can hold 7% more

for every degree Celsius it is warmed. Changes have already been observed in the amount, intensity, frequency, and type of precipitation. Widespread increases in heavy precipitation have occurred even in places where total rain amounts have decreased. In the case of

precipitation In meteorology, precipitation is any product of the condensation of atmospheric water vapor that falls under gravitational pull from clouds. The main forms of precipitation include drizzle, rain, sleet, snow, ice pellets, graupel and hail. ...

, the rising temperatures and extra heat will "intensify" the Earth's

, which means it will increase evaporation. Increased atmospheric water vapour results in more frequent and intense downpours and causes stronger extended droughts in certain regions. As a result, storm-affected areas are likely to experience increases in precipitation and an increased risk of flooding. In contrast, areas far away from storm tracks are likely to experience less precipitation and an increased risk of drought. Overall, there is likely to be longer hot dry spells, broken by more intense heavy rainfalls (along the lines of the English

proverb A proverb (from la, proverbium) is a simple and insightful, traditional saying that expresses a perceived truth based on common sense or experience. Proverbs are often metaphorical and use formulaic language. A proverbial phrase or a proverbia ...

"it never rains but it pours!"). Changes in regional climate are expected to include greater temperature increases over land, with most warming at high northern

latitudes In geography, latitude is a coordinate that specifies the north–south position of a point on the surface of the Earth or another celestial body. Latitude is given as an angle that ranges from –90° at the south pole to 90° at the north pole ...

, and least warming over the

Southern Ocean The Southern Ocean, also known as the Antarctic Ocean, comprises the southernmost waters of the World Ocean, generally taken to be south of 60° S latitude and encircling Antarctica. With a size of , it is regarded as the second-small ...

and parts of the North Atlantic Ocean.IPCC
Synthesis Report Summary for Policymakers

, in . Future changes in precipitation are expected to follow existing trends, with reduced precipitation over subtropical land areas, and increased precipitation at subpolar latitudes and some equatorial regions.

Heat waves and temperature extremes

20211109 Frequency of extreme weather for different degrees of global warming - bar chart IPCC AR6 WG1 SPM

Global heating boosts the probability of

events such as

heat wave A heat wave, or heatwave, is a period of excessively hot weather, which may be accompanied by high humidity, especially in oceanic climate countries. While definitions vary, a heat wave is usually measured relative to the usual climate in the ...

s where the daily maximum temperature exceeds the average maximum temperature by 5 °C (9 °F) for more than five consecutive days. In the last 30–40 years, heat waves with high humidity have become more frequent and severe. Extremely hot nights have doubled in frequency. The area in which extremely hot summers are observed has increased 50–100 fold. Heat waves with high humidity pose a big risk to human health while heat waves with low humidity lead to dry conditions that increase

wildfires A wildfire, forest fire, bushfire, wildland fire or rural fire is an unplanned, uncontrolled and unpredictable fire in an area of combustible vegetation. Depending on the type of vegetation present, a wildfire may be more specifically identif ...

. The mortality from extreme heat is larger than the mortality from hurricanes, lightning, tornadoes, floods, and earthquakes together. It was estimated in 2013 that global warming had increased the probability of local record-breaking monthly temperatures worldwide by a factor of 5. This was compared to a baseline climate in which no global warming had occurred. Using a medium global warming scenario, they project that by 2040, the number of monthly heat records globally could be more than 12 times greater than that of a scenario with no long-term warming. Study results indicate that limiting global warming to 1.5 °C would prevent most of the tropics from reaching the wet-bulb temperature of the human physiological limit of 35 °C. Future climate change will include more very hot days and fewer very cold days. IPCC (2013), Table SPM.1, i
Summary for Policymakers, p. 5(archived PDF)
in The frequency, length and intensity of

s will very likely increase over most land areas. Higher growth in anthropogenic GHG emissions would cause more frequent and severe temperature extremes. Globally, cold waves have decreased in frequency. There is some evidence climate change leads to a weakening of the

polar vortex A circumpolar vortex, or simply polar vortex, is a large region of cold, rotating air that encircles both of Earth's polar regions. Polar vortices also exist on other rotating, low-obliquity planetary bodies. The term polar vortex can be used to ...

, which would make the jet stream more wavy. This would lead to outbursts of very cold winter weather across parts of Eurasia and North America, as well as very warm air incursions into the

Tropical cyclones and storms

Weather-related impacts

Floods

A warming climate will intensify rainfall events. When floods occur in this warmer future, these floods will be more severe. Some regions will experience an increased in flooding, some a decrease. This depends on several factors, such as changes in snowmelt, soil moisture and rainfall. Flooding can be in the form of

urban flooding Urban flooding is the inundation of land or property in a built environment, particularly in more densely populated areas, caused by rainfall overwhelming the capacity of drainage systems, such as storm sewers. Although sometimes triggered by event ...

, river flooding or

coastal flooding Coastal flooding normally occurs when dry and low-lying land is submerged by seawater. The range of a coastal flooding is a result of the elevation of floodwater that penetrates the inland which is controlled by the topography of the coastal land ...

, Sea level rise further increases risks of coastal flooding: if sea levels rise by a further 0.15 m, 20% more people will be exposed to a 1 in a 100 year coastal flood, assuming no population growth and no further adaptation. With an extra 0.75 m, this rises to a doubling of people exposed. Global warming makes bigger storm events more common due to an intensification of the water cycle. This increase in the frequency of large storm events would alter existing Intensity-Duration-Frequency curves (IDF curves) due to the change in frequency, but also by lifting and steepening the curves in the future.

Droughts

Climate change affects multiple factors associated with

drought A drought is defined as drier than normal conditions.Douville, H., K. Raghavan, J. Renwick, R.P. Allan, P.A. Arias, M. Barlow, R. Cerezo-Mota, A. Cherchi, T.Y. Gan, J. Gergis, D. Jiang, A. Khan, W. Pokam Mba, D. Rosenfeld, J. Tierney, an ...

s, such as how much rain falls and how fast the rain

evaporates Evaporation is a type of vaporization that occurs on the surface of a liquid as it changes into the gas phase. High concentration of the evaporating substance in the surrounding gas significantly slows down evaporation, such as when humidi ...

again. Warming over land drives an increase in atmospheric evaporative demand which will increase the severity and frequency of droughts around much of the world. Scientists predict that in some regions of the world, there will be less rain in future due to global warming. These regions will therefore be more prone to drought in future: subtropical regions like the

Mediterranean The Mediterranean Sea is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean Basin and almost completely enclosed by land: on the north by Western Europe, Western and Southern Europe and Anatolia, on the south by North Africa ...

southern Africa Southern Africa is the southernmost subregion of the African continent, south of the Congo and Tanzania. The physical location is the large part of Africa to the south of the extensive Congo River basin. Southern Africa is home to a number o ...

, south-western Australia and south-western

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the sout ...

, as well as tropical

Central America Central America ( es, América Central or ) is a subregion of the Americas. Its boundaries are defined as bordering the United States to the north, Colombia to the south, the Caribbean Sea to the east, and the Pacific Ocean to the west. ...

western Africa West Africa or Western Africa is the westernmost region of Africa. The United Nations defines Western Africa as the 16 countries of Benin, Burkina Faso, Cape Verde, The Gambia, Ghana, Guinea, Guinea-Bissau, Ivory Coast, Liberia, Mali, Maurita ...

and the Amazon basin. Physics dictates that higher temperatures lead to increased evaporation. The effect of this is soil drying and increased plant stress which will have impacts on agriculture. For this reason, even those regions where large changes in precipitation are not expected (such as central and northern Europe) will experience soil drying. The latest prediction of scientists in 2022 is that "If emissions of greenhouse gases are not curtailed, about a third of global land areas are projected to suffer from at least moderate drought by 2100". When droughts occur they are likely to be more intense than in the past. Due to limitations on how much data is available about drought in the past, it is often impossible to confidently

attribute Attribute may refer to: * Attribute (philosophy), an extrinsic property of an object * Attribute (research), a characteristic of an object * Grammatical modifier, in natural languages * Attribute (computing), a specification that defines a prope ...

a specific drought to human-induced climate change. Some areas however, such as the

and

California California is a state in the Western United States, located along the Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the most populous U.S. state and the 3rd largest by area. It is also the m ...

, already show the impacts of human activities. Their impacts are made worse because of increased water demand, population growth, urban expansion, and environmental protection efforts in many areas. The frequency and the duration of droughts have both increased: They increased by 29% from the year 2000 to 2022.Daniel Tsegai, Miriam Medel, Patrick Augenstein, Zhuojing Huang (2022
Drought in Numbers 2022 - restoration for readiness and resilience
United Nations Convention to Combat Desertification (UNCCD) The prediction is that by 2050 more than 75% of humanity will live in drought conditions.

Land restoration Land restoration, which may include renaturalisation or rewilding, is the process of ecological restoration of a site to a natural landscape and habitat, safe for humans, wildlife, and plant communities. Ecological destruction, to which land resto ...

, especially by agroforestry, can help reduce the impact of droughts. In 2019 the Intergovernmental Panel on Climate Change issued a Special Report on Climate Change and Land. The main statements of the report include: Between 1960 and 2013 the area of drylands in drought increased by 1% per year. In 2015, around 500 million people lived in areas impacted by desertification between the 1980s and 2000s. People who live in areas affected by land degradation and desertification are "increasingly negatively affected by climate change". In the past, there were some apparently conflicting results in the scientific literature about how drought is changing due to climate change. This was found to be mostly due to problems with collection and analysis of data, for example in the formulation of the Palmer Drought Severity Index (PDSI) and the data sets used to determine the evapotranspiration component. The accurate attribution of the causes of drought also requires accounting for natural variability, especially

El Niño Southern Oscillation EL, El or el may refer to: Religion * El (deity), a Semitic word for "God" People * EL (rapper) (born 1983), stage name of Elorm Adablah, a Ghanaian rapper and sound engineer * El DeBarge, music artist * El Franco Lee (1949–2016), American p ...

(ENSO) effects and better analysis of precipitation data.

Wildfires

Wildfire acres burned in the United States, OWID

Globally, climate change promotes the type of weather that makes wildfires more likely. In some areas, an increase of wildfires has been attributed directly to climate change. That warmer climate conditions pose more risks of wildfire is consistent with evidence from Earth's past: there was more fire in warmer periods, and less in colder climatic periods. Climate change increases evaporation, which can cause vegetation to dry out. When a fire starts in an area with very dry vegetation, it can spread rapidly. Higher temperatures can also make the fire season longer, the time period in which severe wildfires are most likely. In regions where snow is disappearing, the fire season may get particularly more extended. Even though weather conditions are raising the risks of wildfires, the total area burnt by wildfires has decreased globally. This is mostly the result of the conversion of

savanna A savanna or savannah is a mixed woodland- grassland (i.e. grassy woodland) ecosystem characterised by the trees being sufficiently widely spaced so that the canopy does not close. The open canopy allows sufficient light to reach the ground to ...

into

croplands A farm (also called an agricultural holding) is an area of land that is devoted primarily to agricultural processes with the primary objective of producing food and other crops; it is the basic facility in food production. The name is used f ...

, after which there is less forest area that can burn.

Prescribed burning A controlled or prescribed burn, also known as hazard reduction burning, backfire, swailing, or a burn-off, is a fire set intentionally for purposes of forest management, farming, prairie restoration or greenhouse gas abatement. A control ...

, an indigenous practice in the US and Australia, can reduce the area burnt too, and may form an adaptation to increased risk. The carbon released from wildfires can further increase greenhouse gas concentrations. This feedback is not yet fully integrated into climate models.

Oceans

From 1850 until 2022, the ocean has absorbed 26 % of total anthropogenic emissions. CC-BY_icon

Text was copied from this source, which is available under a Creative Commons Attribution 4.0 International License Emissions during the period 1850–2021 amounted to 670 ± 65 gigatons of carbon and were partitioned among the atmosphere (41 %), ocean (26 %), and land (31 %). Bleached coral (24577819729)

Ice and snow

The

cryosphere ] The cryosphere (from the Ancient Greek, Greek ''kryos'', "cold", "frost" or "ice" and ''sphaira'', "globe, ball") is an all-encompassing term for those portions of Earth's surface where water is in solid form, including sea ice, lake ice, ri ...

, the area of the Earth covered by snow or ice, is extremely sensitive to changes in global climate. Northern Hemisphere average annual snow cover has declined in recent decades. This pattern is consistent with warmer global temperatures. Some of the largest declines have been observed in the spring (season), spring and summer months. During the 21st century,

snow cover Snow comprises individual ice crystals that grow while suspended in the atmosphere—usually within clouds—and then fall, accumulating on the ground where they undergo further changes. It consists of frozen crystalline water throughout ...

is projected to continue its retreat in almost all regions.

Glaciers and ice sheets decline

Since the beginning of the twentieth century, there has been a widespread retreat of glaciers. The melting of the

Greenland Greenland ( kl, Kalaallit Nunaat, ; da, Grønland, ) is an island country in North America that is part of the Kingdom of Denmark. It is located between the Arctic and Atlantic oceans, east of the Canadian Arctic Archipelago. Greenland i ...

and

West Antarctic ice sheet The Western Antarctic Ice Sheet (WAIS) is the segment of the continental ice sheet that covers West Antarctica, the portion of Antarctica on the side of the Transantarctic Mountains that lies in the Western Hemisphere. The WAIS is classified as ...

s will continue to contribute to sea level rise over long time-scales. The Greenland ice sheet loss is mainly driven by melt from the top, whereas Antarctic ice loss is driven by warm ocean water melting the

outlet glacier Glacier morphology, or the form a glacier takes, is influenced by temperature, precipitation, topography, and other factors. The goal of glacial morphology is to gain a better understanding of glaciated landscapes and the way they are shaped. Ty ...

s. Research on Antarctica published in 2022, including the first map of iceberg calving, doubles the previous estimates of loss from ice shelves. Future melt of the

is potentially abrupt under a high emission scenario, as a consequence of a partial collapse. Part of the ice sheet is grounded on bedrock below sea level, making it possibly vulnerable to the self-enhancing process of marine ice sheet instability. A further hypothesis is that ''marine ice cliff instability'' would also contribute to a partial collapse, but limited evidence is available for its importance. A partial collapse of the ice sheet would lead to rapid sea level rise and a local decrease in ocean salinity. It would be irreversible on a timescale between decades and millennia. In contrast to the West Antarctic ice sheet, melt of the Greenland ice sheet is projected to be taking place more gradually over millennia. Sustained warming between 1 °C (low confidence) and 4 °C (medium confidence) would lead to a complete loss of the ice sheet, contributing 7 m to sea levels globally. The ice loss could become irreversible due to a further self-enhancing feedback: the elevation-surface mass balance feedback. When ice melts on top of the ice sheet, the elevation drops. As air temperature is higher at lower

altitude Altitude or height (also sometimes known as depth) is a distance measurement, usually in the vertical or "up" direction, between a reference datum and a point or object. The exact definition and reference datum varies according to the context ...

, this promotes further melt.

Sea ice changes

Sea ice reflects 50% to 70% of the incoming solar radiation, while 6% of the incoming solar energy is reflected by the ocean. With less solar energy, the sea ice absorbs and holds the surface colder, which can be a positive feedback toward climate change. As the climate warms, snow cover and sea ice extent decrease. Large-scale measurements of

sea-ice Sea ice arises as seawater freezes. Because ice is less dense than water, it floats on the ocean's surface (as does fresh water ice, which has an even lower density). Sea ice covers about 7% of the Earth's surface and about 12% of the world's oc ...

have only been possible since the satellite era. The age of the sea ice is an important feature of the state of the sea ice cover.

Arctic sea ice decline

Arctic sea ice began to decline at the beginning of the twentieth century but the rate is accelerating. Since 1979, satellite records indicate the decline in summer sea ice coverage has been about 13% per decade. The thickness of sea ice has also decreased by 66% or 2.0 m over the last six decades with a shift from permanent ice to largely seasonal ice cover. While ice-free summers are expected to be rare at 1.5 °C degrees of warming, they are set to occur at least once every decade at a warming level of 2.0 °C. The Arctic will likely become ice-free at the end of some summers before 2050.Fox-Kemper, B., H.T. Hewitt, C. Xiao, G. Aðalgeirsdóttir, S.S. Drijfhout, T.L. Edwards, N.R. Golledge, M. Hemer, R.E. Kopp, G. Krinner, A. Mix, D. Notz, S. Nowicki, I.S. Nurhati, L. Ruiz, J.-B. Sallée, A.B.A. Slangen, and Y. Yu, 2021
Chapter 9: Ocean, Cryosphere and Sea Level Change
I
Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change
[Masson-Delmotte, V., P. Zhai, A. Pirani, S.L. Connors, C. Péan, S. Berger, N. Caud, Y. Chen, L. Goldfarb, M.I. Gomis, M. Huang, K. Leitzell, E. Lonnoy, J.B.R. Matthews, T.K. Maycock, T. Waterfield, O. Yelekçi, R. Yu, and B. Zhou (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, pp. 1211–1362, doi:10.1017/9781009157896.011.

Sea ice changes in Antarctica

The annual mean Antarctic sea ice area is not showing a clear downwards or upwards trend over the period of reliable satellite data starting in 1979. There are remaining uncertainties on how to interpret this data due to the limited observational records and discrepancies between modelled and observed results for the sea ice cover.

Permafrost thawing

The southern part of the

region (home to 4 million people) has experienced a temperature rise of 1 °C to 3 °C (1.8 °F to 5.4 °F) over the last 50 years. Canada,

Alaska Alaska ( ; russian: Аляска, Alyaska; ale, Alax̂sxax̂; ; ems, Alas'kaaq; Yup'ik: ''Alaskaq''; tli, Anáaski) is a state located in the Western United States on the northwest extremity of North America. A semi-exclave of the U.S. ...

and Russia are experiencing initial melting of permafrost. This may disrupt ecosystems and by increasing bacterial activity in the soil lead to these areas becoming carbon sources instead of

carbon sink A carbon sink is anything, natural or otherwise, that accumulates and stores some carbon-containing chemical compound for an indefinite period and thereby removes carbon dioxide () from the atmosphere. Globally, the two most important carbon si ...

s. Eastern

Siberia Siberia ( ; rus, Сибирь, r=Sibir', p=sʲɪˈbʲirʲ, a=Ru-Сибирь.ogg) is an extensive region, geographical region, constituting all of North Asia, from the Ural Mountains in the west to the Pacific Ocean in the east. It has been a ...

's permafrost is gradually disappearing in the southern regions, leading to the loss of nearly 11% of Siberia's nearly 11,000 lakes since 1971. At the same time, western Siberia is at the initial stage where melting permafrost is creating new lakes, which will eventually start disappearing as in the east. Furthermore, permafrost melting will eventually cause methane release from melting permafrost peat bogs.

Wildlife and nature

Recent warming has strongly affected natural biological systems. Species worldwide are moving poleward to colder areas. On land, species may move to higher elevations, whereas marine species find colder water at greater depths. Of the drivers with the biggest global impact on

nature Nature, in the broadest sense, is the physical world or universe. "Nature" can refer to the phenomena of the physical world, and also to life in general. The study of nature is a large, if not the only, part of science. Although humans are ...

, climate change ranks third over the five decades before 2020, with only change in land use and sea use, and direct exploitation of organisms having a greater impact. The impacts of climate change in nature and nature's contributions to humans are projected to become more pronounced in the next few decades. Examples of climatic disruptions include fire, drought, pest

infestation Infestation is the state of being invaded or overrun by pests or parasites. It can also refer to the actual organisms living on or within a host. Terminology In general, the term "infestation" refers to parasitic diseases caused by animals s ...

, invasion of species, storms, and

coral bleaching Coral bleaching is the process when corals become white due to various stressors, such as changes in temperature, light, or nutrients. Bleaching occurs when coral polyps expel the zooxanthellae ( dinoflagellates that are commonly referred to as a ...

events. The stresses caused by climate change, added to other stresses on ecological systems (e.g. land conversion,

land degradation Land degradation is a process in which the value of the biophysical environment is affected by a combination of human-induced processes acting upon the land. It is viewed as any change or disturbance to the land perceived to be deleterious o ...

, harvesting, and

pollution Pollution is the introduction of contaminants into the natural environment that cause adverse change. Pollution can take the form of any substance (solid, liquid, or gas) or energy (such as radioactivity, heat, sound, or light). Pollutants, the ...

), threaten substantial damage to or complete loss of some unique ecosystems, and

of some critically endangered species. Key interactions between species within ecosystems are often disrupted because species from one location do not move to colder habitats at the same rate, giving rise to rapid changes in the functioning of the ecosystem. Impacts include changes in regional rainfall patterns, earlier leafing of

tree In botany, a tree is a perennial plant with an elongated stem, or trunk, usually supporting branches and leaves. In some usages, the definition of a tree may be narrower, including only woody plants with secondary growth, plants that are ...

s and

plant Plants are predominantly photosynthetic eukaryotes of the kingdom Plantae. Historically, the plant kingdom encompassed all living things that were not animals, and included algae and fungi; however, all current definitions of Plantae exclu ...

s over many regions; movements of species to higher latitudes and altitudes in the Northern Hemisphere; changes in bird migrations in Europe, North America and Australia; and shifting of the oceans'

plankton Plankton are the diverse collection of organisms found in water (or air) that are unable to propel themselves against a current (or wind). The individual organisms constituting plankton are called plankters. In the ocean, they provide a crucia ...

and

fish Fish are aquatic, craniate, gill-bearing animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish as well as various extinct related groups. Approximately 95% of ...

from cold- to warm-adapted communities.

Ecosystems on land

Climate change has been estimated to be a major driver of

biodiversity loss Biodiversity loss includes the worldwide extinction of different species, as well as the local reduction or loss of species in a certain habitat, resulting in a loss of biological diversity. The latter phenomenon can be temporary or permanent, de ...

in cool conifer forests,

s, mediterranean-climate systems,

tropical forest Tropical forests (a.k.a. jungle) are forested landscapes in tropical regions: ''i.e.'' land areas approximately bounded by the tropic of Cancer and Capricorn, but possibly affected by other factors such as prevailing winds. Some tropical fore ...

s, and the

Arctic tundra In physical geography, tundra () is a type of biome where tree growth is hindered by frigid temperatures and short growing seasons. The term ''tundra'' comes through Russian (') from the Kildin Sámi word (') meaning "uplands", "treeless mou ...

., in . In other ecosystems,

land-use Land use involves the management and modification of natural environment or wilderness into built environment such as Human settlement, settlements and semi-natural habitats such as Arable land, arable fields, pastures, and managed Woodland, woo ...

change may be a stronger driver of biodiversity loss, at least in the near-term. Beyond the year 2050, climate change may be the major driver for biodiversity loss globally. Climate change interacts with other pressures such as habitat modification, pollution and invasive species. Interacting with these pressures, climate change increases extinction risk for a large fraction of terrestrial and freshwater species. Between 1% and 50% of species in different groups were assessed to be at substantially higher risk of extinction due to climate change.

Amazon rainforest

20210331 Global tree cover loss - World Resources Institute

Rainfall that falls on the Amazon rainforest is recycled when it

back into the atmosphere instead of running off away from the rainforest. This water is essential for sustaining the rainforest. Due to deforestation the rainforest is losing this ability, exacerbated by climate change which brings more frequent droughts to the area. The higher frequency of droughts seen in the first two decades of the 21st century, as well as other data, signal that a tipping point from rainforest to

might be close. One study concluded that this ecosystem could enter a mode of a 50-years-long collapse to a savanna around 2021, after which it would become increasingly and disproportionally more difficult to prevent or reverse this shift.

Marine ecosystems

Marine heatwave A marine heatwave (MHW) is a period of abnormally high temperatures relative to the average seasonal temperature in a particular region of a sea or ocean. Marine heatwaves are caused by a variety of factors, including shorter term weather phenomena ...

s have seen an increased frequency and have widespread impacts on life in the oceans, such as mass dying events and

. Harmful algae blooms have increased in response to warming waters, loss of oxygen and

eutrophication Eutrophication is the process by which an entire body of water, or parts of it, becomes progressively enriched with minerals and nutrients, particularly nitrogen and phosphorus. It has also been defined as "nutrient-induced increase in phytopla ...

. Between one-quarter and one-third of our fossil fuel emissions are consumed by the earth's oceans, which are now 30 percent more acidic than they were in pre-industrial times. This

acidification Acidification may refer to: * Ocean acidification, decrease in the pH of the Earth's oceans * Freshwater acidification, atmospheric depositions and soil leaching of SOx and NOx * Soil acidification, buildup of hydrogen cations, which reduces the ...

poses a serious threat to aquatic life, particularly creatures such as oysters, clams, and coral with calcified shells or skeletons. Melting sea ice destroys habitat, including for algae that grows on its underside. It is likely that the oceans warmed faster between 1993 and 2017 compared to the period starting in 1969. Warm water coral reefs are very sensitive to global warming and

. Coral reefs provide a

habitat In ecology, the term habitat summarises the array of resources, physical and biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species habitat can be seen as the physical ...

for thousands of species and

ecosystem services Ecosystem services are the many and varied benefits to humans provided by the natural environment and healthy ecosystems. Such ecosystems include, for example, agroecosystems, forest ecosystem, grassland ecosystems, and aquatic ecosystems. ...

such as

coastal protection Coastal management is defence against flooding and erosion, and techniques that stop erosion to claim lands. Protection against rising sea levels in the 21st century is crucial, as sea level rise accelerates due to climate change. Changes in ...

and food. The resilience of reefs can be improved by curbing local pollution and overfishing, but 70–90% of today's warm water coral reefs will disappear even if warming is kept to 1.5 °C. Coral reefs are not the only framework organisms, organisms that build physical structures that form habitats for other sea creatures, affected by climate change:

mangroves A mangrove is a shrub or tree that grows in coastal saline or brackish water. The term is also used for tropical coastal vegetation consisting of such species. Mangroves are taxonomically diverse, as a result of convergent evolution in severa ...

and

seagrass Seagrasses are the only flowering plants which grow in marine environments. There are about 60 species of fully marine seagrasses which belong to four families (Posidoniaceae, Zosteraceae, Hydrocharitaceae and Cymodoceaceae), all in the or ...

are considered to be at moderate risk for lower levels of global warming according to the

Special Report on the Ocean and Cryosphere in a Changing Climate The United Nations' Intergovernmental Panel on Climate Change's (IPCC) Special Report on the Ocean and Cryosphere in a Changing Climate (SROCC) is a report about the effects of climate change on the world's seas, sea ice, icecaps and glaciers. ...

Tipping points and irreversible impacts

Self-reinforcing feedbacks amplify climate change. The climate system exhibits "threshold behaviour" or tipping points when these feedbacks lead parts of the Earth system into a new state, such as the runaway loss of ice sheets or the destruction of forests. Tipping points are studied using data from Earth's distant past and by physical modelling. There is already moderate risk of global tipping points at 1 °C above pre-industrial temperatures, and that risk becomes high at 2.5 °C. Tipping points are "perhaps the most 'dangerous' aspect of future climate changes", leading to irreversible impacts on society. Many tipping points are interlinked, so that triggering one may lead to a cascade of effects, even well below 2 °C of warming. A 2018 study states that 45% of environmental problems, including those caused by climate change are interconnected and make the risk of a

domino effect A domino effect or chain reaction is the cumulative effect generated when a particular event triggers a chain of similar events. This term is best known as a mechanical effect and is used as an analogy to a falling row of dominoes. It typically ...

bigger. There are a number of climate change impacts on the environment that may be irreversible, at least over the timescale of many human generations. These include the large-scale singularities such as the melting of the Greenland and West Antarctic ice sheets, and changes to the Atlantic Meridional Overturning Circulation. In biological systems, the extinction of species would be an irreversible impact. In social systems, unique

culture Culture () is an umbrella term which encompasses the social behavior, institutions, and norms found in human societies, as well as the knowledge, beliefs, arts, laws, customs, capabilities, and habits of the individuals in these groups ...

s may be lost or the survival of endangered languages may be exacerbated due to climate change. For example, humans living on

atoll An atoll () is a ring-shaped island, including a coral rim that encircles a lagoon partially or completely. There may be coral islands or cays on the rim. Atolls are located in warm tropical or subtropical oceans and seas where corals can gr ...

islands face risks due to sea level rise, sea surface warming, and increased frequency and intensity of extreme weather events.

Health, food security and water security

Health

Food security

Climate change will impact agriculture and food production around the world due to the effects of elevated CO₂ in the atmosphere; higher temperatures; altered precipitation and

transpiration Transpiration is the process of water movement through a plant and its evaporation from aerial parts, such as leaves, stems and flowers. Water is necessary for plants but only a small amount of water taken up by the roots is used for growth ...

regimes; increased frequency of extreme events; and modified

weed A weed is a plant considered undesirable in a particular situation, "a plant in the wrong place", or a plant growing where it is not wanted.Harlan, J. R., & deWet, J. M. (1965). Some thoughts about weeds. ''Economic botany'', ''19''(1), 16-24. ...

, pest, and

pathogen In biology, a pathogen ( el, πάθος, "suffering", "passion" and , "producer of") in the oldest and broadest sense, is any organism or agent that can produce disease. A pathogen may also be referred to as an infectious agent, or simply a germ ...

pressure. Droughts result in crop failures and the loss of pasture for livestock. Loss and poor growth of livestock cause milk yield and meat production to decrease. The rate of soil erosion is 10–20 times higher than the rate of soil accumulation in agricultural areas that use

no-till farming No-till farming (also known as zero tillage or direct drilling) is an agricultural technique for growing crops or pasture without disturbing the soil through tillage. No-till farming decreases the amount of soil erosion tillage causes in certai ...

. In areas with

tilling Tilling can mean: * Tillage, an agricultural preparation of the soil. * TILLING (molecular biology) * Tilling is a fictional town in the Mapp and Lucia novels of E. F. Benson. * Tilling Green, Ledshire, is a fictional village in Patricia Wentwo ...

it is 100 times higher. Climate change makes this type of land degradation and desertification worse. Climate change is projected to negatively affect all four pillars of food security: not only how much food is available, but also how easy food is to access (prices), food quality and how stable the food system is. For example, climate change is already affecting the productivity of

wheat Wheat is a grass widely cultivated for its seed, a cereal grain that is a worldwide staple food. The many species of wheat together make up the genus ''Triticum'' ; the most widely grown is common wheat (''T. aestivum''). The archaeologi ...

and other key staples. The availability, quality and stability of wines are impacted by shifts in temperature affecting the traditional range and practices of

viniculture Viticulture (from the Latin word for ''vine'') or winegrowing (wine growing) is the cultivation and harvesting of grapes. It is a branch of the science of horticulture. While the native territory of ''Vitis vinifera'', the common grape vine, ra ...

, and by smoke taint from extreme fire events. In many areas, fisheries have already seen their catch decrease because of global warming and changes in biochemical cycles. In combination with overfishing, warming waters decrease the maximum catch potential. Global catch potential is projected to reduce further in 2050 by less than 4% if emissions are reduced strongly, and by about 8% for very high future emissions, with growth in the

Arctic Ocean The Arctic Ocean is the smallest and shallowest of the world's five major oceans. It spans an area of approximately and is known as the coldest of all the oceans. The International Hydrographic Organization (IHO) recognizes it as an ocean, a ...

Water security

Between 1.5 and 2.5 billion people live in areas with regular

water security Water security is the focused goal of water policy and water management. A society with a high level of water security makes the most of water's benefits for humans and ecosystems and limits the risk of destructive impacts associated with water. T ...

issues. If global warming would reach , water insecurity would affect about twice as many people. Water resources are projected to decrease in most dry subtropical regions and

mid-latitudes The middle latitudes (also called the mid-latitudes, sometimes midlatitudes, or moderate latitudes) are a spatial region on Earth located between the Tropic of Cancer (latitudes 23°26'22") to the Arctic Circle (66°33'39"), and Tropic of Caprico ...

, but increase in high latitudes. However, as streamflow becomes more variable, even regions with increased water resources can experience additional short-term shortages. The arid regions of India, China, the US and Africa are already seeing dry spells and drought impact water availability. Water resources can be affected by climate change in various ways. The total amount of freshwater available can change, for instance due to

dry spell A drought is defined as drier than normal conditions.Douville, H., K. Raghavan, J. Renwick, R.P. Allan, P.A. Arias, M. Barlow, R. Cerezo-Mota, A. Cherchi, T.Y. Gan, J. Gergis, D. Jiang, A. Khan, W. Pokam Mba, D. Rosenfeld, J. Tierney, an ...

s or droughts. Heavy rainfall and flooding can have an impact on water quality: pollutants can be transported into water bodies by the increased surface runoff. In coastal regions, more salt may find its way into water resources due to higher sea levels and more intense storms. Higher temperatures also directly degrade water quality: warm water contains less oxygen.

Economic impacts

20220712 Global economic damage due to greenhouse gas emissions - by country

Economic forecasts of the impact of global warming vary considerably. Researchers have warned that current economic modelling may seriously underestimate the impact of potentially catastrophic climate change, and point to the need for new models that give a more accurate picture of potential damages. Nevertheless, one 2018 study found that potential global economic gains if countries implement mitigation strategies to comply with the 2 °C target set at the Paris Agreement are in the vicinity of US$17 trillion per year up to 2100 compared to a very high emission scenario. Global losses reveal rapidly rising costs due to extreme weather events since the 1970s., in .

Socio-economic Socioeconomics (also known as social economics) is the social science that studies how economic activity affects and is shaped by social processes. In general it analyzes how modern societies progress, stagnate, or regress because of their local ...

factors have contributed to the observed trend of global losses, such as population growth and increased

wealth Wealth is the abundance of valuable financial assets or physical possessions which can be converted into a form that can be used for transactions. This includes the core meaning as held in the originating Old English word , which is from an I ...

. Part of the growth is also related to regional climatic factors, e.g., changes in precipitation and flooding events. It is difficult to quantify the relative impact of socio-economic factors and climate change on the observed trend., p. 55, . The trend does, however, suggest increasing vulnerability of social systems to climate change.

Economic inequality

The_share_of_firms_whose_business_activities_have_been_affected_by_climate_change

Climate change has contributed towards global economic inequality. Wealthy countries in colder regions have either felt little overall economic impact from climate change, or possibly benefited, whereas poor hotter countries very likely grew less than if global warming had not occurred. The total economic impacts from climate change are difficult to estimate, but increase for higher temperature changes. For instance, total damages are estimated to be 90% less if global warming is limited to 1.5 °C compared to 3.66 °C, a warming level chosen to represent no mitigation. One study found a 3.5% reduction in global

GDP Gross domestic product (GDP) is a monetary measure of the market value of all the final goods and services produced and sold (not resold) in a specific time period by countries. Due to its complex and subjective nature this measure is ofte ...

by the end of the century if warming is limited to 3 °C, excluding the potential effect of tipping points. Another study noted that global economic impact is underestimated by a factor of two to eight when tipping points are excluded from consideration. In the Oxford Economics high emission scenario, a temperature rise of 2 degrees by 2050 would reduce global GDP by 2.5% – 7.5%. By the year 2100 in this case, the temperature would rise by 4 degrees, which could reduce the global GDP by 30% in the worst case.

Most affected sectors apart from agriculture and fisheries

Thermal power station A thermal power station is a type of power station in which heat energy is converted to electrical energy. In a steam-generating cycle heat is used to boil water in a large pressure vessel to produce high-pressure steam, which drives a stea ...

s (fossil fuel plants and nuclear power plants) depend on water to cool them. Not only is there increased demand for fresh water, but climate change can increase the likelihood of

and fresh water shortages. Another impact for thermal power plants, is that increasing the temperatures in which they operate reduces their efficiency and hence their output.Dr. Frauke Urban and Dr. Tom Mitchell 2011
Climate change, disasters and electricity generation
. London:

Overseas Development Institute ODI (formerly the 'Overseas Development Institute') is a global affairs think tank, founded in 1960. Its mission is "to inspire people to act on injustice and inequality through collaborative research and ideas that matter for people and the ...

and Institute of Development Studies Changes in the amount of river flow correlate with the amount of energy produced by a dam. The result of diminished river flow can be a power shortage in areas that depend heavily on

hydroelectric power Hydroelectricity, or hydroelectric power, is electricity generated from hydropower (water power). Hydropower supplies one sixth of the world's electricity, almost 4500 TWh in 2020, which is more than all other renewable sources combined an ...

Brazil Brazil ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the largest country in both South America and Latin America. At and with over 217 million people, Brazil is the world's fifth-largest country by area ...

in particular, is vulnerable due to its having reliance on hydroelectricity as increasing temperatures, lower water flow, and alterations in the rainfall regime, could reduce total energy production by 7% annually by the end of the century. Oil and natural gas infrastructure is affected by the effects of climate change and the increased risk of disasters such as

storm A storm is any disturbed state of the natural environment or the atmosphere of an astronomical body. It may be marked by significant disruptions to normal conditions such as strong wind, tornadoes, hail, thunder and lightning (a thunderstorm), ...

, cyclones,

flooding A flood is an overflow of water ( or rarely other fluids) that submerges land that is usually dry. In the sense of "flowing water", the word may also be applied to the inflow of the tide. Floods are an area of study of the discipline hydrolog ...

and

rising sea levels Rising may refer to: * Rising, a stage in baking - see Proofing (baking technique) *Elevation * Short for Uprising, a rebellion Film and TV * "Rising" (''Stargate Atlantis''), the series premiere of the science fiction television program ''Starga ...

Insurance Insurance is a means of protection from financial loss in which, in exchange for a fee, a party agrees to compensate another party in the event of a certain loss, damage, or injury. It is a form of risk management, primarily used to hedge ...

is an important tool to manage risks, but often unavailable to poorer households. Due to climate change, premiums are going up for certain types of insurance, such as

flood insurance Flood insurance is the specific insurance coverage issued against property loss from flooding. To determine risk factors for specific properties, insurers will often refer to topographical maps that denote lowlands, floodplains and other areas tha ...

. Poor adaptation to climate change further widens the gap between what people can afford and the costs of insurance, as risks increase. In 2019,

Munich Re Munich Re Group or Munich Reinsurance Company (german: Münchener Rück; Münchener Rückversicherungs-Gesellschaft) is a German multinational insurance company based in Munich, Germany. It is one of the world's leading reinsurers. ERGO, a Muni ...

noted that climate change could cause

home insurance Home insurance, also commonly called homeowner's insurance (often abbreviated in the US real estate industry as HOI), is a type of property insurance that covers a private residence. It is an insurance policy that combines various personal insura ...

to become unaffordable for households at or below average incomes. Roads, airport runways, railway lines and pipelines, (including oil pipelines, sewers,

water main A water distribution system is a part of water supply network with components that carry potable water from a centralized treatment plant or wells to consumers to satisfy residential, commercial, industrial and fire fighting requirements. Definit ...

s etc.) may require increased maintenance and renewal as they become subject to greater temperature variation. Regions already adversely affected include areas of permafrost, which are subject to high levels of subsidence, resulting in buckling roads, sunken foundations, and severely cracked runways.

Impacts on societies

Climate change impacts

health Health, according to the World Health Organization, is "a state of complete physical, mental and social well-being and not merely the absence of disease and infirmity".World Health Organization. (2006)''Constitution of the World Health Organiza ...

, the availability of drinking water and food,

inequality Inequality may refer to: Economics * Attention inequality, unequal distribution of attention across users, groups of people, issues in etc. in attention economy * Economic inequality, difference in economic well-being between population groups * ...

and economic growth. The effects of climate change are often interlinked and can exacerbate each other as well as existing vulnerabilities. The impacts are often exacerbated by related environmental disruptions and pressures such as

and

. Some areas may become too hot for humans to live in. People in some areas may experience

internal Internal may refer to: *Internality as a concept in behavioural economics *Neijia, internal styles of Chinese martial arts *Neigong or "internal skills", a type of exercise in meditation associated with Daoism *''Internal (album)'' by Safia, 2016 ...

or long-distance displacement (and thus become

climate refugees Climate migrants are a subset of environmental migrants who were forced to flee "due to sudden or gradual alterations in the natural environment related to at least one of three impacts of climate change: sea-level rise, extreme weather events, ...

) triggered by climate change related changes or disasters. The effects of climate change, in combination with the sustained increases in greenhouse gas emissions, have led scientists to characterize it as a "climate emergency" or "

climate crisis ''Climate crisis'' is a term describing global warming and climate change, and their impacts. The term and the alternative term ''climate emergency'' have been used to describe the threat of global warming to humanity (and their planet), and to u ...

". Some climate researchers and activists have called it an "existential threat to civilization".

Displacement and migration

Overlap between future population distribution and extreme heat

Climate change affects displacement of people in several ways. Firstly, involuntary displacement may increase through the increased number and severity of weather-related disasters which destroy homes and habitats. Effects of climate change such as desertification and

gradually erode livelihood and force communities to abandon traditional homelands for more accommodating environments. On the other hand, some households may fall (further) into poverty due to climate change, limiting their ability to move to areas less affected. According to the Internal Displacement Monitoring Centre in 2020 approximately 30 million people were displaced by extreme weather events while approximately 10 million by violence and wars and climate change significantly contributed to this. The United Nations says there are already 64 million migrants in the world fleeing wars, hunger, persecution and the effects of global warming. In 2018, the World Bank estimated that climate change will cause

internal migration Internal migration or domestic migration is human migration within a country. Internal migration tends to be travel for education and for economic improvement or because of a natural disaster or civil disturbance, though a study based on the full ...

of between 31 and 143 million people as they escape crop failures, water scarcity, and sea level rise. The study only included Sub-Saharan Africa, South Asia, and Latin America. Majuro_-_Main_Atoll_of_the_RMI

Asia and the Pacific is the global area most prone to natural disasters, both in terms of the absolute number of disasters and of populations affected. It is highly exposed to climate impacts, and is home to highly vulnerable population groups, who are disproportionately poor and marginalized. A 2015 Asian Development Bank report highlights "environmental hot spots" that are particular risk of flooding, cyclones,

typhoons A typhoon is a mature tropical cyclone that develops between 180° and 100°E in the Northern Hemisphere. This region is referred to as the Northwestern Pacific Basin, and is the most active tropical cyclone basin on Earth, accounting for a ...

, and water stress. Gradual but pervasive environmental change and sudden natural disasters both influence the nature and extent of human migration but in different ways.

United Nations High Commissioner for Refugees The United Nations High Commissioner for Refugees (UNHCR) is a United Nations agency mandated to aid and protect refugees, forcibly displaced communities, and stateless people, and to assist in their voluntary repatriation, local integrati ...

stated that climate change increases mass displacement, in many regions, including Sahel, East Africa, South Asia, the "drought corridor" in Latin America. 90% of refugees comes from "climate vulnerable hotspots". Some Pacific Ocean island nations, such as

Tuvalu Tuvalu ( or ; formerly known as the Ellice Islands) is an island country and microstate in the Polynesian subregion of Oceania in the Pacific Ocean. Its islands are situated about midway between Hawaii and Australia. They lie east-nor ...

Kiribati Kiribati (), officially the Republic of Kiribati ( gil, ibaberikiKiribati),Kiribati
''The Wor ...

, and the

Maldives Maldives (, ; dv, ދިވެހިރާއްޖެ, translit=Dhivehi Raajje, ), officially the Republic of Maldives ( dv, ދިވެހިރާއްޖޭގެ ޖުމްހޫރިއްޔާ, translit=Dhivehi Raajjeyge Jumhooriyyaa, label=none, ), is an archipelag ...

, are considering the eventual possibility of evacuation, as flood defense may become economically unrealistic. Governments have considered various approaches to reduce migration compelled by environmental conditions in at-risk communities, including programs of social protection, livelihoods development, basic urban infrastructure development, and disaster risk management. Some experts support migration as an appropriate way for people to cope with environmental changes. However, this is controversial because migrants – particularly low-skilled ones – are among the most vulnerable people in society and are often denied basic protections and access to services. Slow-onset disasters and gradual environmental erosion such as desertification, reduction of soil fertility, coastal erosion and sea-level rise are likely to induce long-term migration. Migration related to desertification and reduced soil fertility is likely to be predominantly from

rural area In general, a rural area or a countryside is a geographic area that is located outside towns and cities. Typical rural areas have a low population density and small settlements. Agricultural areas and areas with forestry typically are descr ...

s in

developing countries A developing country is a sovereign state with a lesser developed industrial base and a lower Human Development Index (HDI) relative to other countries. However, this definition is not universally agreed upon. There is also no clear agreem ...

to towns and cities., p. 109, .

Conflict

Climate change can worsen conflicts by exacerbating tensions over limited resources like

drinking water Drinking water is water that is used in drink or food preparation; potable water is water that is safe to be used as drinking water. The amount of drinking water required to maintain good health varies, and depends on physical activity level, a ...

(in the case of

water conflict Water conflict is a term describing a conflict between countries, states, or groups over the rights to access water resources. The United Nations recognizes that water disputes result from opposing interests of water users, public or private. A ...

s). Climate change also has the potential to cause large population dislocations and migration, which can also lead to increased tensions. However, factors other than climate change are judged to be substantially more important in affecting conflict. These factors include intergroup

and low socio-economic development. In some cases, climate change can even lead to more peaceful relationships between groups, as environmental problems requires common policy to be developed. Global warming has been described as a "threat multiplier". Certain conditions make it more likely that climate change impacts conflict: ethnic exclusion, an economy dependent on agriculture, insufficient infrastructure, poor local governance, and low levels of development. A spike in wheat prices following crop losses from a period of drought may have contributed to the onset of the "

Arab Spring The Arab Spring ( ar, الربيع العربي) was a series of anti-government protests, uprisings and armed rebellions that spread across much of the Arab world in the early 2010s. It began in Tunisia in response to corruption and econo ...

" protests and revolutions in 2010.

Social impacts on vulnerable groups

The impacts of climate change on humans are not distributed uniformly within communities. Individual and social factors such as gender, age, education, ethnicity, geography and language lead to differential

vulnerability Vulnerability refers to "the quality or state of being exposed to the possibility of being attacked or harmed, either physically or emotionally." A window of vulnerability (WOV) is a time frame within which defensive measures are diminished, com ...

and capacity to adapt to the effects of climate change. The following more vulnerable groups have been identified: * People living in poverty: Climate change disproportionally affects poor people in low-income communities and

around the world. Those in poverty have a higher chance of experiencing the ill-effects of climate change due to the increased exposure and vulnerability. A 2020 World Bank paper estimated that between 32 million to 132 million additional people will be pushed into extreme poverty by 2030 due to climate change. *

Women A woman is an adult female human. Prior to adulthood, a female human is referred to as a girl (a female child or adolescent). The plural ''women'' is sometimes used in certain phrases such as "women's rights" to denote female humans regardl ...

: Climate change increases

gender inequality Gender inequality is the social phenomenon in which men and women are not treated equally. The treatment may arise from distinctions regarding biology, psychology, or cultural norms prevalent in the society. Some of these distinctions are empi ...

, reduces women's ability to be financially independent, and has an overall negative impact on the social and political

rights of women Women's rights are the rights and entitlements claimed for women and girls worldwide. They formed the basis for the women's rights movement in the 19th century and the feminist movements during the 20th and 21st centuries. In some countries, ...

, especially in economies that are heavily based on agriculture. *

Indigenous peoples Indigenous peoples are culturally distinct ethnic groups whose members are directly descended from the earliest known inhabitants of a particular geographic region and, to some extent, maintain the language and culture of those original people ...

: Indigenous communities geographically tend to be located in regions more vulnerable to climate change such as native rainforests, the

, and coastal areas. Indigenous communities across the globe generally have economic disadvantages that are not as prevalent in non-indigenous communities due to the ongoing oppression they have experienced. These disadvantages include lower education levels and higher rates of poverty and unemployment, which add to their vulnerability to climate change. * Children: The Lancet review on health and climate change lists children as the worst-affected category by climate change. Children are also 14–44 percent more likely to die from environmental factors, again leaving them the most vulnerable. Those in urban areas will be affected by lower air quality and overcrowding, and will struggle the most to better their situation. * Racial minorities: The

environmental justice Environmental justice is a social movement to address the unfair exposure of poor and marginalized communities to harms from hazardous waste, resource extraction, and other land uses.Schlosberg, David. (2007) ''Defining Environmental Justic ...

(EJ) movement and climate justice (CJ) movement address environmental racism in bringing attention and enacting change so that marginalized populations are not disproportionately vulnerable to climate change and

Human settlements

A major challenge for human settlements is

sea level rise Globally, sea levels are rising due to human-caused climate change. Between 1901 and 2018, the globally averaged sea level rose by , or 1–2 mm per year on average.IPCC, 2019Summary for Policymakers InIPCC Special Report on the Ocean and Cry ...

, indicated by ongoing observation and research of rapid declines in ice-mass balance from both Greenland and Antarctica. Estimates for 2100 are at least twice as large as previously estimated by IPCC AR4, with an upper limit of about two meters. Depending on regional changes, increased precipitation patterns can cause more flooding or extended drought stresses water resources. A 2020 study projects that regions inhabited by a third of the human population could become as hot as the hottest parts of the Sahara within 50 years without a change in patterns of population growth and without

migration Migration, migratory, or migrate may refer to: Human migration * Human migration, physical movement by humans from one region to another ** International migration, when peoples cross state boundaries and stay in the host state for some minimum le ...

, unless greenhouse gas emissions are reduced. The projected annual average temperature of above 29 °C for these regions would be outside the "human temperature niche" – a suggested range for climate biologically suitable for humans based on historical data of mean annual temperatures (MAT) – and the most affected regions have little adaptive capacity as of 2020. In small islands and megadeltas,

inundation A flood is an overflow of water ( or rarely other fluids) that submerges land that is usually dry. In the sense of "flowing water", the word may also be applied to the inflow of the tide. Floods are an area of study of the discipline hydrolog ...

as a result of

is expected to threaten vital infrastructure and human settlements. This could lead to issues of statelessness for populations in countries such as the

and

and homelessness in countries with low-lying areas such as

Bangladesh Bangladesh (}, ), officially the People's Republic of Bangladesh, is a country in South Asia. It is the eighth-most populous country in the world, with a population exceeding 165 million people in an area of . Bangladesh is among the mos ...

. In 1991, 140,000 people died and the 10 million became homeless when the floods hit Bangladesh. In Myanmar, the storm killed 146,000 people which was hit in 2007. Climate change threatens the health and survival of urban trees and the various benefits they deliver to urban inhabitants.

Projections for cities in 2050

In 2019 the Crowther Lab from ETH

Zürich , neighboring_municipalities = Adliswil, Dübendorf, Fällanden, Kilchberg, Maur, Oberengstringen, Opfikon, Regensdorf, Rümlang, Schlieren, Stallikon, Uitikon, Urdorf, Wallisellen, Zollikon , twintowns = Kunming, San Francisco Zürich ...

paired the climatic conditions of 520 major cities worldwide with the predicted climatic conditions of cities in 2050. 22% of the major cities are predicted to have climatic conditions that do not exist in any city today. 2050

London London is the capital and List of urban areas in the United Kingdom, largest city of England and the United Kingdom, with a population of just under 9 million. It stands on the River Thames in south-east England at the head of a estuary dow ...

will have a climate similar to 2019

Melbourne Melbourne ( ; Boonwurrung/Woiwurrung: ''Narrm'' or ''Naarm'') is the capital and most populous city of the Australian state of Victoria, and the second-most populous city in both Australia and Oceania. Its name generally refers to a met ...

Athens Athens ( ; el, Αθήνα, Athína ; grc, Ἀθῆναι, Athênai (pl.) ) is both the capital and largest city of Greece. With a population close to four million, it is also the seventh largest city in the European Union. Athens dominates ...

and

Madrid Madrid ( , ) is the capital and most populous city of Spain. The city has almost 3.4 million inhabitants and a Madrid metropolitan area, metropolitan area population of approximately 6.7 million. It is the Largest cities of the Europ ...

Fez, Morocco Fez or Fes (; ar, فاس, fās; zgh, ⴼⵉⵣⴰⵣ, fizaz; french: Fès) is a city in northern inland Morocco and the capital of the Fès-Meknès, Fès-Meknès administrative region. It is the List of cities in Morocco, second largest city i ...

Nairobi Nairobi ( ) is the capital and largest city of Kenya. The name is derived from the Maasai phrase ''Enkare Nairobi'', which translates to "place of cool waters", a reference to the Nairobi River which flows through the city. The city proper h ...

Maputo Maputo (), formerly named Lourenço Marques until 1976, is the capital, and largest city of Mozambique. Located near the southern end of the country, it is within of the borders with Eswatini and South Africa. The city has a population of 1,0 ...

. The Indian city

Pune Pune (; ; also known as Poona, ( the official name from 1818 until 1978) is one of the most important industrial and educational hubs of India, with an estimated population of 7.4 million As of 2021, Pune Metropolitan Region is the largest i ...

will be like

Bamako Bamako ( bm, ߓߡߊ߬ߞߐ߬ ''Bàmakɔ̌'', ff, 𞤄𞤢𞤥𞤢𞤳𞤮 ''Bamako'') is the capital and largest city of Mali, with a 2009 population of 1,810,366 and an estimated 2022 population of 2.81 million. It is located on the Niger Rive ...

Mali Mali (; ), officially the Republic of Mali,, , ff, 𞤈𞤫𞤲𞥆𞤣𞤢𞥄𞤲𞤣𞤭 𞤃𞤢𞥄𞤤𞤭, Renndaandi Maali, italics=no, ar, جمهورية مالي, Jumhūriyyāt Mālī is a landlocked country in West Africa. Mal ...

, Bamako will be like

Niamey Niamey () is the capital and largest city of Niger. Niamey lies on the Niger River, primarily situated on the east bank. Niamey's population was counted as 1,026,848 as of the 2012 census. As of 2017, population projections show the capital dis ...

Niger ) , official_languages = , languages_type = National languagesBrasilia will be like Goiania. Increased extreme heat exposure from both climate change and the

urban heat island effect An urban heat island (UHI) is an urban area, urban or metropolitan area that is significantly warmer than its surrounding rural areas due to human impact on the environment, human activities. The temperature difference is usually larger at nigh ...

threatens urban settlements.

Especially affected regions

The

Africa Africa is the world's second-largest and second-most populous continent, after Asia in both cases. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 6% of Earth's total surface area ...

, small islands,

Asia Asia (, ) is one of the world's most notable geographical regions, which is either considered a continent in its own right or a subcontinent of Eurasia, which shares the continental landmass of Afro-Eurasia with Africa. Asia covers an are ...

n megadeltas and

the Middle East The Middle East ( ar, الشرق الأوسط, ISO 233: ) is a geopolitical region commonly encompassing Arabia (including the Arabian Peninsula and Bahrain), Asia Minor (Asian part of Turkey except Hatay Province), East Thrace (Europea ...

are regions that are likely to be especially affected by climate change., in . Low-latitude, less-developed regions are at most risk of experiencing negative impacts due to climate change. The ten countries of the

Association of Southeast Asian Nations ASEAN ( , ), officially the Association of Southeast Asian Nations, is a political and economic union of 10 member states in Southeast Asia, which promotes intergovernmental cooperation and facilitates economic, political, security, militar ...

(ASEAN) are among the most vulnerable in the world to the negative effects of climate change, however, ASEAN's climate mitigation efforts are not commensurate with the climate change threats the region faces.

is one of the most vulnerable continents to climate variability and change because of multiple existing stresses and low adaptive capacity. Climate change is projected to decrease freshwater availability in central, south, east and southeast Asia, particularly in large

river basin A drainage basin is an area of land where all flowing surface water converges to a single point, such as a river mouth, or flows into another body of water, such as a lake or ocean. A basin is separated from adjacent basins by a perimeter, t ...

s. With population growth and increasing demand from higher standards of living, this decrease could adversely affect more than a billion people by the 2050s. Small islands, whether located in the tropics or higher latitudes, are already exposed to extreme weather events and changes in sea level. This existing exposure will likely make these areas sensitive to the effects of climate change.

Developed countries A developed country (or industrialized country, high-income country, more economically developed country (MEDC), advanced country) is a sovereign state that has a high quality of life, developed economy and advanced technological infrastruct ...

are also vulnerable to climate change, and have already been negatively affected by increases in the severity and frequency of some

events, such as heat waves, floods, wildfires, and tropical cyclones.

Low-lying coastal regions

Cyclone Nargis flooding before-and-after

For historical reasons to do with

trade Trade involves the transfer of goods and services from one person or entity to another, often in exchange for money. Economists refer to a system or network that allows trade as a market. An early form of trade, barter, saw the direct excha ...

, many of the world's largest and most prosperous cities are on the

coast The coast, also known as the coastline or seashore, is defined as the area where land meets the ocean, or as a line that forms the boundary between the land and the coastline. The Earth has around of coastline. Coasts are important zones in ...

. In developing countries, the poorest often live on

floodplain A floodplain or flood plain or bottomlands is an area of land adjacent to a river which stretches from the banks of its channel to the base of the enclosing valley walls, and which experiences flooding during periods of high discharge.Goudi ...

s, because it is the only available space, or fertile agricultural land. These settlements often lack infrastructure such as dykes and early warning systems. Poorer communities also tend to lack the insurance, savings, or access to credit needed to recover from disasters. Socioeconomic impacts of climate change in coastal and low-lying areas will be overwhelmingly adverse. The following impacts were projected in 2007 with very high confidence: *Coastal and low-lying areas would be exposed to increasing risks including coastal erosion due to climate change and sea level rise. *By the 2080s, millions of people would experience floods every year due to sea level rise. The numbers affected were projected to be largest in the densely populated and low-lying mega-deltas of Asia and Africa; and smaller islands were judged to be especially vulnerable. Given high coastal

population density Population density (in agriculture: Stock (disambiguation), standing stock or plant density) is a measurement of population per unit land area. It is mostly applied to humans, but sometimes to other living organisms too. It is a key geographical ...

, estimates of the number of people at risk of

from climate-driven sea-level rise varies from 190 million, to 300 million or even 640 million in a worst-case scenario related to the instability of the Antarctic ice sheet. The most people affected are in the densely-populated and low-lying megadeltas of Asia and Africa. The Greenland ice sheet is estimated to have reached a point of no return, continuing to melt even if warming stopped. Over time that would submerge many of the world's coastal cities including low-lying islands, especially combined with storm surges and high tides.

Small islands

Small islands developing states are especially vulnerable to the effects of climate change, especially sea level rise. They are expected to experience more intense storm surges, salt water intrusion, and coastal destruction. Low-lying small islands in the Pacific, Indian, and Caribbean regions are at risk of permanent inundation and population displacement. On the islands of Fiji,

Tonga Tonga (, ; ), officially the Kingdom of Tonga ( to, Puleʻanga Fakatuʻi ʻo Tonga), is a Polynesian country and archipelago. The country has 171 islands – of which 45 are inhabited. Its total surface area is about , scattered over in ...

and western

Samoa Samoa, officially the Independent State of Samoa; sm, Sāmoa, and until 1997 known as Western Samoa, is a Polynesian island country consisting of two main islands ( Savai'i and Upolu); two smaller, inhabited islands ( Manono and Apolima); ...

, concentrations of migrants from outer islands inhabit low and unsafe areas along the coasts.

Atoll An atoll () is a ring-shaped island, including a coral rim that encircles a lagoon partially or completely. There may be coral islands or cays on the rim. Atolls are located in warm tropical or subtropical oceans and seas where corals can gr ...

nations, which include countries that are composed entirely of the smallest form of islands, called motus, are at risk of entire population displacement. These nations include

Kiribati Kiribati (), officially the Republic of Kiribati ( gil, ibaberikiKiribati),Kiribati
''The Wor ...

, the

Marshall Islands The Marshall Islands ( mh, Ṃajeḷ), officially the Republic of the Marshall Islands ( mh, Aolepān Aorōkin Ṃajeḷ),'' () is an independent island country and microstate near the Equator in the Pacific Ocean, slightly west of the Intern ...

Tokelau Tokelau (; ; known previously as the Union Islands, and, until 1976, known officially as the Tokelau Islands) is a dependent territory of New Zealand in the southern Pacific Ocean. It consists of three tropical coral atolls: Atafu, Nukunonu, a ...

, and

. Vulnerability is increased by small size, isolation from other land, low financial resources, and lack of protective infrastructure. A study that engaged the experiences of residents in atoll communities found that the cultural identities of these populations are strongly tied to these lands. Human rights activists argue that the potential loss of entire atoll countries, and consequently the loss of national sovereignty, self-determination, cultures, and indigenous lifestyles cannot be compensated for financially. Some researchers suggest that the focus of international dialogues on these issues should shift from ways to relocate entire communities to strategies that instead allow for these communities to remain on their lands.

Possibility of societal collapse

Several researchers have suggested that collapse of the current societal organization – the contemporary global, interconnected

civilization A civilization (or civilisation) is any complex society characterized by the development of a state, social stratification, urbanization, and symbolic systems of communication beyond natural spoken language (namely, a writing system). ...

– could occur at 3 degrees of warming, especially when considering that climate change is not the only environmental pressure and challenge humanity faces.

Possible responses

The magnitude of future impacts of

can be reduced by climate change mitigation and adaptation. Mitigation policies currently in place will result in about 2.7 °C (2.0–3.6 °C, depending on how sensitive the climate is to greenhouse gas emissions) warming above pre-industrial levels. If all unconditional pledges and targets made by governments are achieved the temperature will rise by around 2.4 °C. If additionally all the countries that adopted or are considering to adopt net-zero targets will achieve it the temperature will rise by a median of 1.8 °C. There is a substantial gap between national plans and commitments and actions so far taken by governments around the world.

References

Sources

* (pb: ). * (pb: ). * . * . Summary for Policymaker
available
in Arabic, Chinese, French, Russian, and Spanish. *
Climate Change 2013 Working Group 1 website.
* . Archived * * * * * *

External links

IPCC Working Group I (WG I)
Intergovernmental Panel on Climate Change group which assesses the physical scientific aspects of the climate system and climate change.
Climate
from the

World Meteorological Organization The World Meteorological Organization (WMO) is a specialized agency of the United Nations responsible for promoting international cooperation on atmospheric science, climatology, hydrology and geophysics. The WMO originated from the Intern ...

Climate change
UN Department of Economic and Social Affairs Sustainable Development
Effects of climate change
from the Met Office
United Nations Environment Programme and climate change
Climate change and society Glob Articles containing video clips {{Authority control

Observed and future changes in temperature

Weather-related changes

Rain and snow

Heat waves and temperature extremes

Tropical cyclones and storms

Weather-related impacts

Floods

Droughts

Wildfires

Oceans

Ice and snow

Glaciers and ice sheets decline

Sea ice changes

Arctic sea ice decline

Sea ice changes in Antarctica

Permafrost thawing

Wildlife and nature

Ecosystems on land

Amazon rainforest

Marine ecosystems

Tipping points and irreversible impacts

Health, food security and water security

Health

Food security

Water security

Economic impacts

Economic inequality

Most affected sectors apart from agriculture and fisheries

Impacts on societies

Displacement and migration

Conflict

Social impacts on vulnerable groups

Human settlements

Projections for cities in 2050

Especially affected regions

Low-lying coastal regions

Small islands

Possibility of societal collapse

Possible responses

See also

References

Sources

External links