The Earth System Grid (ESG) is a data distribution portal whose development is funded mainly by the United States Department of Energy. It is the portal through which the Program for Climate Model Diagnosis and Intercomparison at Lawrence Livermore National Laboratory is distributing data for the IPCC Fourth Assessment Report and the 2014 IPCC Fifth Assessment Report. [1]
The scientific community has been investigating the causes of climate change for decades. After thousands of studies, it came to a consensus, where it is "unequivocal that human influence has warmed the atmosphere, ocean and land since pre-industrial times." This consensus is supported by around 200 scientific organizations worldwide, The dominant role in this climate change has been played by the direct emissions of carbon dioxide from the burning of fossil fuels. Indirect CO2 emissions from land use change, and the emissions of methane, nitrous oxide and other greenhouse gases play major supporting roles.
Climate is the long-term weather pattern in a region, typically averaged over 30 years. More rigorously, it is the mean and variability of meteorological variables over a time spanning from months to millions of years. Some of the meteorological variables that are commonly measured are temperature, humidity, atmospheric pressure, wind, and precipitation. In a broader sense, climate is the state of the components of the climate system, including the atmosphere, hydrosphere, cryosphere, lithosphere and biosphere and the interactions between them. The climate of a location is affected by its latitude, longitude, terrain, altitude, land use and nearby water bodies and their currents.
Global warming potential (GWP) is an index to measure how much infrared thermal radiation a greenhouse gas would absorb over a given time frame after it has been added to the atmosphere. The GWP makes different greenhouse gases comparable with regard to their "effectiveness in causing radiative forcing". It is expressed as a multiple of the radiation that would be absorbed by the same mass of added carbon dioxide, which is taken as a reference gas. Therefore, the GWP has a value of 1 for CO2. For other gases it depends on how strongly the gas absorbs infrared thermal radiation, how quickly the gas leaves the atmosphere, and the time frame being considered.
The Intergovernmental Panel on Climate Change (IPCC) is an intergovernmental body of the United Nations. Its job is to advance scientific knowledge about climate change caused by human activities. The World Meteorological Organization (WMO) and the United Nations Environment Programme (UNEP) set up the IPCC in 1988. The United Nations endorsed the creation of the IPCC later that year. It has a secretariat in Geneva, Switzerland, hosted by the WMO. It has 195 member states who govern the IPCC. The member states elect a bureau of scientists to serve through an assessment cycle. A cycle is usually six to seven years. The bureau selects experts in their fields to prepare IPCC reports. There is a formal nomination process by governments and observer organizations to find these experts. The IPCC has three working groups and a task force, which carry out its scientific work.
A general circulation model (GCM) is a type of climate model. It employs a mathematical model of the general circulation of a planetary atmosphere or ocean. It uses the Navier–Stokes equations on a rotating sphere with thermodynamic terms for various energy sources. These equations are the basis for computer programs used to simulate the Earth's atmosphere or oceans. Atmospheric and oceanic GCMs are key components along with sea ice and land-surface components.
The IPCC Third Assessment Report (TAR), Climate Change 2001, is an assessment of available scientific and socio-economic information on climate change by the IPCC. Statements of the IPCC or information from the TAR were often used as a reference showing a scientific consensus on the subject of global warming. The Third Assessment Report (TAR) was completed in 2001 and consists of four reports, three of them from its Working Groups: Working Group I: The Scientific Basis; Working Group II: Impacts, Adaptation and Vulnerability; Working Group III: Mitigation; Synthesis Report. A number of the TAR's conclusions are given quantitative estimates of how probable it is that they are correct, e.g., greater than 66% probability of being correct. These are "Bayesian" probabilities, which are based on an expert assessment of all the available evidence.
HadCM3 is a coupled atmosphere-ocean general circulation model (AOGCM) developed at the Hadley Centre in the United Kingdom. It was one of the major models used in the IPCC Third Assessment Report in 2001.
In climatology, the Coupled Model Intercomparison Project (CMIP) is a collaborative framework designed to improve knowledge of climate change. It was organized in 1995 by the Working Group on Coupled Modelling (WGCM) of the World Climate Research Programme (WCRP). It is developed in phases to foster the climate model improvements but also to support national and international assessments of climate change. A related project is the Atmospheric Model Intercomparison Project (AMIP) for global coupled ocean-atmosphere general circulation models (GCMs).
Climate sensitivity is a key measure in climate science and describes how much Earth's surface will warm for a doubling in the atmospheric carbon dioxide (CO2) concentration. Its formal definition is: "The change in the surface temperature in response to a change in the atmospheric carbon dioxide (CO2) concentration or other radiative forcing." This concept helps scientists understand the extent and magnitude of the effects of climate change.
The Special Report on Emissions Scenarios (SRES) is a report by the Intergovernmental Panel on Climate Change (IPCC) that was published in 2000. The greenhouse gas emissions scenarios described in the Report have been used to make projections of possible future climate change. The SRES scenarios, as they are often called, were used in the IPCC Third Assessment Report (TAR), published in 2001, and in the IPCC Fourth Assessment Report (AR4), published in 2007. The SRES scenarios were designed to improve upon some aspects of the IS92 scenarios, which had been used in the earlier IPCC Second Assessment Report of 1995. The SRES scenarios are "baseline" scenarios, which means that they do not take into account any current or future measures to limit greenhouse gas (GHG) emissions.
Land use, land-use change, and forestry (LULUCF), also referred to as Forestry and other land use (FOLU) or Agriculture, Forestry and Other Land Use (AFOLU), is defined as a "greenhouse gas inventory sector that covers emissions and removals of greenhouse gases resulting from direct human-induced land use such as settlements and commercial uses, land-use change, and forestry activities."
The IPCC supplementary report of 1992 was published to contribute to the debate on the United Nations Framework Convention on Climate Change at the 1992 Earth Summit, held in Rio de Janeiro.
The IPCC Fourth Assessment Report (AR4) is a report on climate change created with the help of a large number of contributors, both scientists and governmental representatives. There has been considerable political controversy over a small number of errors found in the report, and there have been calls for review of the process used to formulate the report. The overwhelming majority view of scientists with expertise in climate change is that errors, when found, are corrected, and the issues as identified do not undermine the conclusions of the report that the climate system is warming in response to increased levels of greenhouse gases, largely due to human activities.
The Fifth Assessment Report (AR5) of the United Nations Intergovernmental Panel on Climate Change (IPCC) is the fifth in a series of such reports and was completed in 2014. As had been the case in the past, the outline of the AR5 was developed through a scoping process which involved climate change experts from all relevant disciplines and users of IPCC reports, in particular representatives from governments. Governments and organizations involved in the Fourth Report were asked to submit comments and observations in writing with the submissions analysed by the panel. Projections in AR5 are based on "Representative Concentration Pathways" (RCPs). The RCPs are consistent with a wide range of possible changes in future anthropogenic greenhouse gas emissions. Projected changes in global mean surface temperature and sea level are given in the main RCP article.
Greenhouse gases (GHGs) are the gases in the atmosphere that raise the surface temperature of planets such as the Earth. What distinguishes them from other gases is that they absorb the wavelengths of radiation that a planet emits, resulting in the greenhouse effect. The Earth is warmed by sunlight, causing its surface to radiate heat, which is then mostly absorbed by greenhouse gases. Without greenhouse gases in the atmosphere, the average temperature of Earth's surface would be about −18 °C (0 °F), rather than the present average of 15 °C (59 °F).
Atmospheric methane is the methane present in Earth's atmosphere. The concentration of atmospheric methane is increasing due to methane emissions, and is causing climate change. Methane is one of the most potent greenhouse gases. Methane's radiative forcing (RF) of climate is direct, and it is the second largest contributor to human-caused climate forcing in the historical period. Methane is a major source of water vapour in the stratosphere through oxidation; and water vapour adds about 15% to methane's radiative forcing effect. The global warming potential (GWP) for methane is about 84 in terms of its impact over a 20-year timeframe, and 28 in terms of its impact over a 100-year timeframe.
The Common Metadata for Climate Modelling Digital Repositories, or METAFOR project, is creating a Common Information Model (CIM) for climate data and the models that produce it.
The Global Organization of Earth System Science Portals or (GO-ESSP) is an international collaboration, formed in 2003, that is developing software infrastructure to support the distribution, and analysis of climate model data and related observations.
The contributions of women in climate change have received increasing attention in the early 21st century. Feedback from women and the issues faced by women have been described as "imperative" by the United Nations and "critical" by the Population Reference Bureau. A report by the World Health Organization concluded that incorporating gender-based analysis would "provide more effective climate change mitigation and adaptation."