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Climate change

Climate change
Climate change is a change in the statistical distribution of weather patterns when that change lasts for an extended period of time (i.e., decades to millions of years). Climate change may refer to a change in average weather conditions, or in the time variation of weather around longer-term average conditions (i.e., more or fewer extreme weather events). Climate change is caused by factors such as biotic processes, variations in solar radiation received by Earth, plate tectonics, and volcanic eruptions. Certain human activities have also been identified as significant causes of recent climate change, often referred to as "global warming".[1] §Terminology The most general definition of climate change is a change in the statistical properties of the climate system when considered over long periods of time, regardless of cause.[2] Accordingly, fluctuations over periods shorter than a few decades, such as El Niño, do not represent climate change. §Causes §Internal forcing mechanisms §Life

Folgen der globalen Erwärmung Eine Karte der prognostizierten globalen Erwärmung zum Ende des 21. Jahrhunderts. In diesem verwendeten HadCM3-Klimamodell beträgt die durchschnittliche Erwärmung 3 °C. Die Folgen der globalen Erwärmung sind zahlreiche, den Menschen und seine Umwelt betreffende, weltweite Veränderungen. Während weitgehend Einigkeit über die Ursachen der globalen Erwärmung besteht[1] (hauptsächlich menschliche Emissionen von Treibhausgasen), werden ihre Folgen intensiv erörtert (siehe dazu auch unter: Kontroverse um die globale Erwärmung). Nach einer Studie des Stockholm Resilience Centre von 2009 ist der ermittelte Grenzwert für den Kohlendioxidgehalt der Atmosphäre bereits um 11 % überschritten, so dass der anthropogene Klimawandel nach dem Artensterben das zweitgrößte globale ökologische Problem darstellt. Erwartetes Ausmaß der globalen Erwärmung[Bearbeiten] Einige Projektionen der Temperaturentwicklung bis 2100: Zwischen 2 und 5 °C Erhöhung in 100 Jahren… Umweltauswirkungen[Bearbeiten]

List of climate scientists Climate scientists study the statistics of the Earth's temperature (top) and precipitation (bottom) for a better understanding of the climate system. This list of climate scientists contains famous or otherwise notable persons who have contributed to the study of climate science. The list is not complete or up to date. A[edit] B[edit] Sallie Baliunas, American, astrophysicist, solar variation.Robert Balling, American, former director of the Office of Climatology and is a professor of geography at Arizona State University, climatology, global climate change, and geographic information systems.[4]Édouard Bard, French climate scientist, specialized in past climate reconstruction.Richard A. C[edit] E[edit] Kerry Emanuel (1955- ), American, atmospheric dynamics specializing in hurricanes.[8]Matthew England (1966-), Australian, physical oceanographer and climate dynamicist. F[edit] G[edit] H[edit] Joanna Haigh, British, solar variabilityJames E. J[edit] K[edit] Thomas R. L[edit] M[edit] O[edit] P[edit]

Climate change feedback Climate change feedback is important in the understanding of global warming because feedback processes may amplify or diminish the effect of each climate forcing, and so play an important part in determining the climate sensitivity and future climate state. Feedback in general is the process in which changing one quantity changes a second quantity, and the change in the second quantity in turn changes the first. Positive feedback amplifies the change in the first quantity while negative feedback reduces it.[1] The term "forcing" means a change which may "push" the climate system in the direction of warming or cooling.[2] An example of a climate forcing is increased atmospheric concentrations of greenhouse gases. By definition, forcings are external to the climate system while feedbacks are internal; in essence, feedbacks represent the internal processes of the system. Positive[edit] Carbon cycle feedbacks[edit] Arctic methane release[edit] Methane release from hydrates[edit]

Climate sensitivity Frequency distribution of climate sensitivity, based on model simulations.[1] Few of the simulations result in less than 2 °C of warming—near the low end of estimates by the Intergovernmental Panel on Climate Change (IPCC).[1] Some simulations result in significantly more than the 4 °C, which is at the high end of the IPCC estimates.[1] This pattern (statisticians call it a "right-skewed distribution") suggests that if carbon dioxide concentrations double, the probability of very large increases in temperature is greater than the probability of very small increases.[1] Although climate sensitivity is usually used in the context of radiative forcing by carbon dioxide (CO2), it is thought of as a general property of the climate system: the change in surface air temperature (ΔTs) following a unit change in radiative forcing (RF), and thus is expressed in units of °C/(W/m2). For coupled atmosphere-ocean global climate models (e.g. Equilibrium and transient climate sensitivity[edit]

Airborne fraction The airborne fraction is a scaling factor defined as the ratio of the annual increase in atmospheric CO 2 to the CO 2 emissions from anthropogenic sources.[1] It represents the proportion of human emitted CO2 that remains in the atmosphere. The fraction averages about 45%, meaning that approximately half the human-emitted CO 2 is absorbed by ocean and land surfaces. There is some evidence for a recent increase in airborne fraction, which would imply a faster increase in atmospheric CO 2 for a given rate of human fossil-fuel burning.[2] However, other sources suggest that the "fraction of carbon dioxide has not increased either during the past 150 years or during the most recent five decades".[3][4] Changes in carbon sinks can affect the airborne fraction. Jump up ^ Forster, P, V Ramaswamy, P Artaxo, et al. (2007) Changes in Atmospheric Constituents and in Radiative Forcing.

Intergovernmental Panel on Climate Change The Intergovernmental Panel on Climate Change (IPCC) is a scientific intergovernmental body under the auspices of the United Nations,[1][2] set up at the request of member governments.[3] It was first established in 1988 by two United Nations organizations, the World Meteorological Organization (WMO) and the United Nations Environment Programme (UNEP), and later endorsed by the United Nations General Assembly through Resolution 43/53. Membership of the IPCC is open to all members of the WMO and UNEP.[4] The IPCC is chaired by Rajendra K. Pachauri. The IPCC does not carry out its own original research, nor does it do the work of monitoring climate or related phenomena itself. The IPCC bases its assessment on the published literature, which includes peer-reviewed and non-peer-reviewed sources.[7] Thousands of scientists and other experts contribute (on a voluntary basis, without payment from the IPCC)[8] to writing and reviewing reports, which are then reviewed by governments. Aims[edit]

United Nations Framework Convention on Climate Change The United Nations Framework Convention on Climate Change (UNFCCC) is an international environmental treaty negotiated at the United Nations Conference on Environment and Development (UNCED), informally known as the Earth Summit, held in Rio de Janeiro from 3 to 14 June 1992. The objective of the treaty is to "stabilize greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic interference with the climate system".[2] The treaty itself set no binding limits on greenhouse gas emissions for individual countries and contains no enforcement mechanisms. The UNFCCC was opened for signature on 9 May 1992, after an Intergovernmental Negotiating Committee produced the text of the Framework Convention as a report following its meeting in New York from 30 April to 9 May 1992. The parties to the convention have met annually from 1995 in Conferences of the Parties (COP) to assess progress in dealing with climate change. Treaty[edit] Later negotiations[edit]

Kyoto Protocol Kyoto Parties with first period (2008–12) greenhouse gas emissions limitations targets, and the percentage change in their carbon dioxide emissions from fuel combustion between 1990 and 2009. For more detailed country/region information, see Kyoto Protocol and government action. Overview map of states committed to greenhouse gas (GHG) limitations in the first Kyoto Protocol period (2008–12):[8] Dark grey = Annex I Parties who have agreed to reduce their GHG emissions below their individual base year levels (see definition in this article) Grey = Annex I Parties who have agreed to cap their GHG emissions at their base year levels Pale grey = Non-Annex I Parties who are not obligated by caps or Annex I Parties with an emissions cap that allows their emissions to expand above their base year levels or countries that have not ratified the Kyoto Protocol The European Union as a whole has in accordance with the Kyoto Protocol committed itself to an 8% reduction. Background[edit] Asia[edit]

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