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Divergence Problem
The divergence problem is an anomaly from the field of dendroclimatology, the study of past climate through observations of old trees, primarily the properties of their annual growth rings. It is the disagreement between instrumental temperatures (measured by thermometers) and the temperatures reconstructed from latewood densities or, in some cases, from the widths of tree rings in far northern forests. While the thermometer records indicate a substantial late 20th century warming trend, many tree rings from such sites do not display a corresponding change in their maximum latewood density. In some studies this issue has also been found with tree ring width. A temperature trend extracted from tree rings alone would not show any substantial warming since the 1950s. The temperature graphs calculated in these two ways thus "diverge" from one another, which is the origin of the term. Discovery The problem of changing response of some tree ring proxies to recent climate changes w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lamont–Doherty Earth Observatory
The Lamont–Doherty Earth Observatory (LDEO) is the scientific research center of the Columbia Climate School, and a unit of The Earth Institute at Columbia University. It focuses on climate and earth sciences and is located on a 189-acre (64 ha) campus in Palisades, New York, north of Manhattan on the Hudson River. History The Lamont–Doherty Earth Observatory (LDEO) was established in 1949 as the Lamont Geological Observatory on the weekend estate of Thomas W. and Florence Haskell Corliss Lamont, which was donated to the university for that purpose. The Observatory's founder and first director was Maurice "Doc" Ewing, a seismologist who is credited with advancing efforts to study the solid Earth, particularly in areas related to using sound waves to image rock and sediments beneath the ocean floor. He was also the first to collect sediment core samples from the bottom of the ocean, a common practice today that helps scientists study changes in the planet's climate a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Climatic Research Unit Documents
Climatic Research Unit documents including thousands of e-mails and other computer files were stolen from a server at the Climatic Research Unit of the University of East Anglia in a hacking incident in November 2009. The documents were redistributed first through several blogs of global warming deniers, who alleged that the documents indicated misconduct by leading climate scientists. A series of investigations rejected these allegations, while concluding that CRU scientists should have been more open with distributing data and methods on request. Precisely six committees investigated the allegations and published reports, finding no evidence of fraud or scientific misconduct. The scientific consensus that global warming is occurring as a result of human activity remained unchanged by the end of the investigations. The incident occurred shortly before the opening December 2009 Copenhagen global climate summit. It has prompted general discussion about increasing the openness ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Climatic Research Unit Email Controversy
The Climatic Research Unit email controversy (also known as "Climategate") began in November 2009 with the hacking of a server at the Climatic Research Unit (CRU) at the University of East Anglia (UEA) by an external attacker, copying thousands of emails and computer files (the Climatic Research Unit documents) to various internet locations several weeks before the Copenhagen Summit on climate change. The story was first broken by climate change denialists, who argued that the emails showed that global warming was a scientific conspiracy and that scientists manipulated climate data and attempted to suppress critics. The CRU rejected this, saying that the emails had been taken out of context. FactCheck.org confirmed that climate change deniers misrepresented the contents of the emails. Columnist James Delingpole popularised the term "Climategate" to describe the controversy. The mainstream media picked up the story, as negotiations over climate change mitigation began in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aerosol
An aerosol is a suspension of fine solid particles or liquid droplets in air or another gas. Aerosols can be natural or anthropogenic. Examples of natural aerosols are fog or mist, dust, forest exudates, and geyser steam. Examples of anthropogenic aerosols include particulate air pollutants, mist from the discharge at hydroelectric dams, irrigation mist, perfume from atomizers, smoke, steam from a kettle, sprayed pesticides, and medical treatments for respiratory illnesses. When a person inhales the contents of a vape pen or e-cigarette, they are inhaling an anthropogenic aerosol. The liquid or solid particles in an aerosol have diameters typically less than 1 μm (larger particles with a significant settling speed make the mixture a suspension, but the distinction is not clear-cut). In general conversation, ''aerosol'' often refers to a dispensing system that delivers a consumer product from a can. Diseases can spread by means of small droplets in the breath, so ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Global Dimming
Global dimming is the reduction in the amount of global direct irradiance at the Earth's surface that has been observed since systematic measurements began in the 1950s. The effect varies by location, but worldwide it has been estimated to be of the order of a 4–20% reduction. However, after discounting an anomaly caused by the eruption of Mount Pinatubo in 1991, a very slight reversal in the overall trend has been observed. Global dimming is thought to have been caused by an increase in particulates or aerosols, such as sulfate aerosols in the atmosphere due to human action. It has interfered with the hydrological cycle by reducing evaporation and may have reduced rainfall in some areas. Global dimming has been attributed as the leading factor in the 1984 Ethiopian famine by reducing heating at the tropics which drives the annual monsoon, or wet season. Causes It is thought that global dimming is probably due to the increased presence of aerosol particles in Earth's atmosp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nonlinear System
In mathematics and science, a nonlinear system is a system in which the change of the output is not proportional to the change of the input. Nonlinear problems are of interest to engineers, biologists, physicists, mathematicians, and many other scientists because most systems are inherently nonlinear in nature. Nonlinear dynamical systems, describing changes in variables over time, may appear chaotic, unpredictable, or counterintuitive, contrasting with much simpler linear systems. Typically, the behavior of a nonlinear system is described in mathematics by a nonlinear system of equations, which is a set of simultaneous equations in which the unknowns (or the unknown functions in the case of differential equations) appear as variables of a polynomial of degree higher than one or in the argument of a function which is not a polynomial of degree one. In other words, in a nonlinear system of equations, the equation(s) to be solved cannot be written as a linear combination of t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Global Warming
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 Earth's climate. The current rise in global average temperature is more rapid than previous changes, and is primarily caused by humans burning fossil fuels. Fossil fuel use, deforestation, and some agricultural and industrial practices increase greenhouse gases, notably carbon dioxide and methane. Greenhouse gases absorb some of the heat that the Earth radiates after it warms from sunlight. Larger amounts of these gases trap more heat in Earth's lower atmosphere, causing global warming. Due to climate change, deserts are expanding, while heat waves and wildfires are becoming more common. Increased warming in the Arctic has contributed to melting permafrost, glacial retreat and sea ice loss. Higher temperatures are also causing ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The Christian Science Monitor
''The Christian Science Monitor'' (''CSM''), commonly known as ''The Monitor'', is a nonprofit news organization that publishes daily articles in electronic format as well as a weekly print edition. It was founded in 1908 as a daily newspaper by Mary Baker Eddy, the founder of the Church of Christ, Scientist. , the print circulation was 75,052. According to the organization's website, "the Monitor's global approach is reflected in how Mary Baker Eddy described its object as 'To injure no man, but to bless all mankind.' The aim is to embrace the human family, shedding light with the conviction that understanding the world's problems and possibilities moves us towards solutions." ''The Christian Science Monitor'' has won seven Pulitzer Prizes and more than a dozen Overseas Press Club awards. Reporting Despite its name, the ''Monitor'' is not a religious-themed paper, and does not promote the doctrine of its patron, the Church of Christ, Scientist. However, at its founder ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Columbia University
Columbia University (also known as Columbia, and officially as Columbia University in the City of New York) is a private research university in New York City. Established in 1754 as King's College on the grounds of Trinity Church in Manhattan, Columbia is the oldest institution of higher education in New York and the fifth-oldest institution of higher learning in the United States. It is one of nine colonial colleges founded prior to the Declaration of Independence. It is a member of the Ivy League. Columbia is ranked among the top universities in the world. Columbia was established by royal charter under George II of Great Britain. It was renamed Columbia College in 1784 following the American Revolution, and in 1787 was placed under a private board of trustees headed by former students Alexander Hamilton and John Jay. In 1896, the campus was moved to its current location in Morningside Heights and renamed Columbia University. Columbia scientists and scholars h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proxy (climate)
In the study of past climates ("paleoclimatology"), climate proxies are preserved physical characteristics of the past that stand in for direct meteorological measurements and enable scientists to reconstruct the climatic conditions over a longer fraction of the Earth's history. Reliable global records of climate only began in the 1880s, and proxies provide the only means for scientists to determine climatic patterns before record-keeping began. A large number of climate proxies have been studied from a variety of geologic contexts. Examples of proxies include stable isotope measurements from ice cores, growth rates in tree rings, species composition of sub-fossil pollen in lake sediment or foraminifera in ocean sediments, temperature profiles of boreholes, and stable isotopes and mineralogy of corals and carbonate speleothems. In each case, the proxy indicator has been influenced by a particular seasonal climate parameter (e.g., summer temperature or monsoon intensity) at the t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dendroclimatology
Dendroclimatology is the science of determining past climates from trees (primarily properties of the annual tree rings). Tree rings are wider when conditions favor growth, narrower when times are difficult. Other properties of the annual rings, such as maximum latewood density (MXD) have been shown to be better proxies than simple ring width. Using tree rings, scientists have estimated many local climates for hundreds to thousands of years previous. By combining multiple tree-ring studies (sometimes with other climate proxy records), scientists have estimated past regional and global climates. Advantages Tree rings are especially useful as climate proxies in that they can be well-dated via dendrochronology, i.e. matching of the rings from sample to sample. This allows extension backwards in time using deceased tree samples, even using samples from buildings or from archeological digs. Another advantage of tree rings is that they are clearly demarked in annual increments, as op ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
