Land surface effects on climate are wide-ranging and vary by region. Deforestation and exploitation of natural landscapes play a significant role. Some of these environmental changes are similar to those caused by the

effects of global warming The effects of climate change impact the physical environment, ecosystems and human societies. The environmental effects of climate change are broad and far-reaching. They affect the water cycle, oceans, sea and land ice (glaciers), sea lev ...

Deforestation effects

Major land surface changes affecting climate include

deforestation Deforestation or forest clearance is the removal of a forest or stand of trees from land that is then converted to non-forest use. Deforestation can involve conversion of forest land to farms, ranches, or urban use. The most concentrated ...

(especially in tropical areas), and destruction of grasslands and xeric woodlands by

overgrazing Overgrazing occurs when plants are exposed to intensive grazing for extended periods of time, or without sufficient recovery periods. It can be caused by either livestock in poorly managed agricultural applications, game reserves, or nature res ...

, or lack of grazing. These changes in the natural landscape reduce

evapotranspiration Evapotranspiration (ET) is the combined processes by which water moves from the earth’s surface into the atmosphere. It covers both water evaporation (movement of water to the air directly from soil, canopies, and water bodies) and transpi ...

, and thus

water vapor (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 p ...

, in the atmosphere, limiting clouds and

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. ...

. It has been proposed, in the journal

Atmospheric Chemistry and Physics ''Atmospheric Chemistry and Physics'' is an open access peer-reviewed scientific journal published by the European Geosciences Union. It covers research on the Earth's atmosphere and the underlying chemical and physical processes, including the al ...

, that evaporation rates from forested areas may exceed that of the oceans, creating zones of low pressure, which enhance the development of storms and rainfall through atmospheric

moisture recycling In hydrology, moisture recycling or precipitation recycling refer to the process by which a portion of the precipitated water that evapotranspired from a given area contributes to the precipitation over the same area. Moisture recycling is thus a c ...

. The

American Institute of Biological Sciences The American Institute of Biological Sciences (AIBS) is a nonprofit scientific charity. The organization’s mission is to promote the use of science to inform decision-making and advance biology for the benefit of science and society. Overvie ...

published a similar paper in support of this concept in 2009. In addition, with deforestation and/or destruction of grasslands, the amount of

dew Dew is water in the form of droplets that appears on thin, exposed objects in the morning or evening due to condensation. As the exposed surface cools by radiating its heat, atmospheric moisture condenses at a rate greater than that at wh ...

harvested (or condensed) by plants is greatly diminished. All of this contributes to desertification in these regions. In an article published b
Science
it is mentioned that 25-50% of the rainfall in the Amazon basin comes from the forest, and if deforestation reaches 30-40% most of the Amazon basin will enter a permanent dry climate. This concept of land-atmosphere feedback is common among permaculturists, such as

Masanobu Fukuoka was a Japanese farmer and philosopher celebrated for his natural farming and re-vegetation of desertified lands. He was a proponent of no-till, herbicide and pesticide free cultivation methods from which he created a particular method of agricu ...

, who, in his book, ''The One Straw Revolution'', said "rain comes from the ground, not the sky." Deforestation, and conversion of grasslands to desert, may also lead to cooling of the regional climate. This is because of the

albedo Albedo (; ) is the measure of the diffuse reflection of solar radiation out of the total solar radiation and measured on a scale from 0, corresponding to a black body that absorbs all incident radiation, to 1, corresponding to a body that refl ...

effect (sunlight reflected by bare ground) during the day, and rapid radiation of heat into space at night, due to the lack of

vegetation Vegetation is an assemblage of plant species and the ground cover they provide. It is a general term, without specific reference to particular taxa, life forms, structure, spatial extent, or any other specific botanical or geographic characte ...

and atmospheric moisture.

Reforestation Reforestation (occasionally, reafforestation) is the natural or intentional restocking of existing forests and woodlands (forestation) that have been depleted, usually through deforestation, but also after clearcutting. Management A debat ...

conservation grazing Conservation grazing or targeted grazing is the use of semi- feral or domesticated grazing livestock to maintain and increase the biodiversity of natural or semi-natural grasslands, heathlands, wood pasture, wetlands and many other habitats.

, holistic land management, and, in

drylands Drylands are defined by a scarcity of water. Drylands are zones where precipitation is balanced by evaporation from surfaces and by transpiration by plants (evapotranspiration). The United Nations Environment Program defines drylands as tropical ...

, water harvesting and

keyline design Keyline design is a landscaping technique of maximizing the beneficial use of the water resources of a tract of land. The "keyline" is a specific topographic feature related to the natural flow of water on the tract. Keyline design is a system o ...

, are examples of methods that might help prevent or lessen these drying effects.

Mountain meteorological effects

Orographic lift

Orographic lift occurs when an

air mass In meteorology, an air mass is a volume of air defined by its temperature and humidity. Air masses cover many hundreds or thousands of square miles, and adapt to the characteristics of the surface below them. They are classified according to l ...

is forced from a low

elevation The elevation of a geographic location is its height above or below a fixed reference point, most commonly a reference geoid, a mathematical model of the Earth's sea level as an equipotential gravitational surface (see Geodetic datum § Ver ...

to a higher elevation as it moves over rising

terrain Terrain or relief (also topographical relief) involves the vertical and horizontal dimensions of land surface. The term bathymetry is used to describe underwater relief, while hypsometry studies terrain relative to sea level. The Latin wo ...

. As the air mass gains

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 ...

it quickly cools down adiabatically, which can raise the

relative humidity Humidity is the concentration of water vapor present in the air. Water vapor, the gaseous state of water, is generally invisible to the human eye. Humidity indicates the likelihood for precipitation, dew, or fog to be present. Humidity dep ...

to 100% and create

cloud In meteorology, a cloud is an aerosol consisting of a visible mass of miniature liquid droplets, frozen crystals, or other particles suspended in the atmosphere of a planetary body or similar space. Water or various other chemicals may ...

s and, under the right conditions,

Rain shadow

A rain shadow is a dry area on the leeward side of a mountainous area (away from the wind). The mountains block the passage of rain-producing weather systems and cast a "shadow" of dryness behind them. Wind and moist air is drawn by the prevailing winds towards the top of the mountains, where it condenses and precipitates before it crosses the top. In an effect opposite that of orographic lift, the air, without much moisture left, advances behind the mountains creating a drier side called the "rain shadow".

Foehn wind

A föhn or foehn is a type of dry, warm, down-slope wind that occurs in the lee (downwind side) of a mountain range. Storm Oratia 30 Oct 2000

It is a rain shadow wind that results from the subsequent adiabatic warming of air that has dropped most of its moisture on windward slopes (''see''

orographic lift Orographic lift occurs when an air mass is forced from a low elevation to a higher elevation as it moves over rising terrain. As the air mass gains altitude it quickly cools down adiabatically, which can raise the relative humidity to 100% and cr ...

). As a consequence of the different adiabatic lapse rates of moist and dry air, the air on the leeward slopes becomes warmer than equivalent elevations on the

windward Windward () and leeward () are terms used to describe the direction of the wind. Windward is ''upwind'' from the point of reference, i.e. towards the direction from which the wind is coming; leeward is ''downwind'' from the point of reference ...

slopes. Föhn winds can raise

temperature Temperature is a physical quantity that expresses quantitatively the perceptions of hotness and coldness. Temperature is measurement, measured with a thermometer. Thermometers are calibrated in various Conversion of units of temperature, temp ...

s by as much as 14 °C (25 °F) in just a matter of minutes. Central Europe enjoys a warmer climate due to the Föhn, as moist winds off the Mediterranean Sea blow over the

Alps The Alps () ; german: Alpen ; it, Alpi ; rm, Alps ; sl, Alpe . are the highest and most extensive mountain range system that lies entirely in Europe, stretching approximately across seven Alpine countries (from west to east): France, Swi ...

References

External links

YouTube interview with Susan Martinez, Ph.D., on "global drying" theoryYouTube presentation: "Do forests attract rain?" from the Center for International Forestry ResearchYouTube TEDx presentation by Peter Westerveld on restored land helping to bring rainYouTube TED presentation by Allan Savory on using conservation grazing to green desert areasYouTube: "Green Desert," a documentary film about the effects of deforestation in Indonesia
{{Doomsday Climate change and the environment Climate change feedbacks Climate forcing Deforestation Desertification Forest conservation