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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.
There is a nearly unanimous scientific consensus that the Earth has been consistently warming since the start of the Industrial Revolution, that the rate of recent warming is largely unprecedented, and that this warming is mainly the result of a rapid increase in atmospheric carbon dioxide (CO2) caused by human activities. The human activities causing this warming include fossil fuel combustion, cement production, and land use changes such as deforestation, with a significant supporting role from the other greenhouse gases such as methane and nitrous oxide. This human role in climate change is considered "unequivocal" and "incontrovertible".
In glaciology, an ice sheet, also known as a continental glacier, is a mass of glacial ice that covers surrounding terrain and is greater than 50,000 km2 (19,000 sq mi). The only current ice sheets are the Antarctic ice sheet and the Greenland ice sheet. Ice sheets are bigger than ice shelves or alpine glaciers. Masses of ice covering less than 50,000 km2 are termed an ice cap. An ice cap will typically feed a series of glaciers around its periphery.
The West 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. It is classified as a marine-based ice sheet, meaning that its bed lies well below sea level and its edges flow into floating ice shelves. The WAIS is bounded by the Ross Ice Shelf, the Ronne Ice Shelf, and outlet glaciers that drain into the Amundsen Sea.
The Antarctic ice sheet is a continental glacier covering 98% of the Antarctic continent, with an area of 14 million square kilometres and an average thickness of over 2 kilometres (1.2 mi). It is the largest of Earth's two current ice sheets, containing 26.5 million cubic kilometres of ice, which is equivalent to 61% of all fresh water on Earth. Its surface is nearly continuous, and the only ice-free areas on the continent are the dry valleys, nunataks of the Antarctic mountain ranges, and sparse coastal bedrock. However, it is often subdivided into East Antarctic ice sheet (EAIS), West Antarctic ice sheet (WAIS), and Antarctic Peninsula (AP), due to the large differences in topography, ice flow, and glacier mass balance between the three regions.
Jonathan Michael Gregory is a climate modeller working on mechanisms of global and large-scale change in climate and sea level on multidecadal and longer timescales at the Met Office and the University of Reading.
Effects of climate change are well documented and growing for Earth's natural environment and human societies. Changes to the climate system include an overall warming trend, changes to precipitation patterns, and more extreme weather. As the climate changes it impacts the natural environment with effects such as more intense forest fires, thawing permafrost, and desertification. These changes impact ecosystems and societies, and can become irreversible once tipping points are crossed. Climate activists are engaged in a range of activities around the world that seek to ameliorate these issues or prevent them from happening.
Present-day climate change includes both global warming—the ongoing increase in global average temperature—and its wider effects on Earth's climate. Climate change in a broader sense also includes previous long-term changes to Earth's climate. The current rise in global temperatures is driven by human activities, especially fossil fuel burning since the Industrial Revolution. Fossil fuel use, deforestation, and some agricultural and industrial practices release greenhouse gases. These gases absorb some of the heat that the Earth radiates after it warms from sunlight, warming the lower atmosphere. Carbon dioxide, the primary greenhouse gas driving global warming, has grown by about 50% and is at levels not seen for millions of years.
Richard Blane Alley is an American geologist and Evan Pugh Professor of Geosciences at Pennsylvania State University. He has authored more than 240 refereed scientific publications about the relationships between Earth's cryosphere and global climate change, and is recognized by the Institute for Scientific Information as a Highly Cited Researcher.
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.
Due to climate change in the Arctic, this polar region is expected to become "profoundly different" by 2050. The speed of change is "among the highest in the world", with the rate of warming being 3-4 times faster than the global average. This warming has already resulted in the profound Arctic sea ice decline, the accelerating melting of the Greenland ice sheet and the thawing of the permafrost landscape. These ongoing transformations are expected to be irreversible for centuries or even millennia.
In climate science, a tipping point is a critical threshold that, when crossed, leads to large, accelerating and often irreversible changes in the climate system. If tipping points are crossed, they are likely to have severe impacts on human society and may accelerate global warming. Tipping behavior is found across the climate system, for example in ice sheets, mountain glaciers, circulation patterns in the ocean, in ecosystems, and the atmosphere. Examples of tipping points include thawing permafrost, which will release methane, a powerful greenhouse gas, or melting ice sheets and glaciers reducing Earth's albedo, which would warm the planet faster. Thawing permafrost is a threat multiplier because it holds roughly twice as much carbon as the amount currently circulating in the atmosphere.
Between 1901 and 2018, the average sea level rose by 15–25 cm (6–10 in), with an increase of 2.3 mm (0.091 in) per year since the 1970s. This was faster than the sea level had ever risen over at least the past 3,000 years. The rate accelerated to 4.62 mm (0.182 in)/yr for the decade 2013–2022. Climate change due to human activities is the main cause. Between 1993 and 2018, melting ice sheets and glaciers accounted for 44% of sea level rise, with another 42% resulting from thermal expansion of water.
Hans Joachim "John" Schellnhuber is a German atmospheric physicist, climatologist and founding director of the Potsdam Institute for Climate Impact Research (PIK) and former chair of the German Advisory Council on Global Change (WBGU). Since 1 December 2023, Schellnhuber is the Director General of IIASA.
Climate change feedbacks are natural processes that impact how much global temperatures will increase for a given amount of greenhouse gas emissions. Positive feedbacks amplify global warming while negative feedbacks diminish it. Feedbacks influence both the amount of greenhouse gases in the atmosphere and the amount of temperature change that happens in response. While emissions are the forcing that causes climate change, feedbacks combine to control climate sensitivity to that forcing.
Global surface temperature (GST) is the average temperature of Earth's surface. More precisely, it is the weighted average of the temperatures over the ocean and land. The former is also called sea surface temperature and the latter is called surface air temperature. Temperature data comes mainly from weather stations and satellites. To estimate data in the distant past, proxy data can be used for example from tree rings, corals, and ice cores. Observing the rising GST over time is one of the many lines of evidence supporting the scientific consensus on climate change, which is that human activities are causing climate change. Alternative terms for the same thing are global mean surface temperature (GMST) or global average surface temperature.
Alan Robock is an American climatologist. He is currently a Distinguished Professor in the Department of Environmental Sciences at Rutgers University, New Jersey. He advocates nuclear disarmament and, in 2010 and 2011, met with Fidel Castro during lecture trips to Cuba to discuss the dangers of nuclear weapons. Alan Robock was a 2007 IPCC author, a member of the organisation when it was awarded the Nobel Peace Prize, "for their efforts to build up and disseminate greater knowledge about man-made climate change, and to lay the foundations for the measures that are needed to counteract such change".
Climate change caused by greenhouse gas emissions from human activities occurs everywhere on Earth, and while Antarctica is less vulnerable to it than any other continent, climate change in Antarctica has been observed. Since 1959, there has been an average temperature increase of >0.05 °C/decade since 1957 across the continent, although it had been uneven. West Antarctica warmed by over 0.1 °C/decade from the 1950s to the 2000s, and the exposed Antarctic Peninsula has warmed by 3 °C (5.4 °F) since the mid-20th century. The colder, stabler East Antarctica had been experiencing cooling until the 2000s. Around Antarctica, the Southern Ocean has absorbed more oceanic heat than any other ocean, and has seen strong warming at depths below 2,000 m (6,600 ft). Around the West Antarctic, the ocean has warmed by 1 °C (1.8 °F) since 1955.
Brian C. O'Neill is an American earth system scientist who studies the relationship between future societal development, emissions, and climate change impacts. O'Neill is known for interdisciplinary work on climate and human systems, in particular population and climate change. He was also involved in the development of the shared socioeconomic pathways (SSPs) to be used in scenario analysis. He served as a lead author for several Intergovernmental Panel on Climate Change reports.
Solomon M. Hsiang is an American scientist and economist who directs the Global Policy Laboratory and is the Chancellor’s Professor of Public Policy at the University of California, Berkeley. He co-founded the Climate Impact Lab and is a National Geographic Explorer. Hsiang’s work has been featured in media articles and impacted policy across international and US federal institutions.
References
- 1 2 3 Princeton University. "Michael Oppenheimer" . Retrieved 7 July 2020.
- 1 2 Oppenheimer, Michael; Oreskes, Naomi; Jamieson, Dale; Brysse, Keynyn; O'Reilly, Jessica; Shindell, Matthew; Wazeck, Milena (2019). Discerning experts : the practices of scientific assessment for environmental policy. The University of Chicago Press. ISBN 9780226602011 . Retrieved 7 July 2020.
- ↑ "Michael Oppenheimer and the End of the Climate As You Know It". Princeton Magazine. June 1, 2015. Archived from the original on March 21, 2016. Retrieved July 23, 2023.
- 1 2 "The Heinz Awards: Michael Oppenheimer". The Heinz Awards. Retrieved August 26, 2016.
- ↑ Feng, S.; Krueger, A. B.; Oppenheimer, M. (26 July 2010). "Linkages among climate change, crop yields and Mexico-US cross-border migration". Proceedings of the National Academy of Sciences. 107 (32): 14257–14262. Bibcode:2010PNAS..10714257F. doi: 10.1073/pnas.1002632107 . PMC 2922556 . PMID 20660749.
- ↑ Feng, S.; Oppenheimer, M. (20 August 2012). "Applying statistical models to the climate-migration relationship". Proceedings of the National Academy of Sciences. 109 (43): E2915. Bibcode:2012PNAS..109E2915F. doi: 10.1073/pnas.1212226109 . PMC 3491464 . PMID 22908301.
- 1 2 Oppenheimer, M.; O'Neill, B. C.; Webster, M.; Agrawala, S. (14 September 2007). "The Limits of Consensus". Science. 317 (5844): 1505–1506. doi:10.1126/science.1144831. PMID 17872430. S2CID 129837694.
- 1 2 Yohe, Gary; Oppenheimer, Michael (13 August 2011). "Evaluation, characterization, and communication of uncertainty by the intergovernmental panel on climate change—an introductory essay". Climatic Change. 108 (4): 629–639. Bibcode:2011ClCh..108..629Y. doi: 10.1007/s10584-011-0176-8 .
- ↑ O’Reilly, Jessica; Oreskes, Naomi; Oppenheimer, Michael (26 June 2012). "The rapid disintegration of projections: The West Antarctic Ice Sheet and the Intergovernmental Panel on Climate Change". Social Studies of Science. 42 (5): 709–731. doi:10.1177/0306312712448130. PMID 23189611. S2CID 33619256.
- ↑ Brysse, Keynyn; Naomi Oreskes; Jessica O’Reilly; Michael Oppenheimer (Feb 2013). "Climate change prediction: Erring on the side of least drama?". Global Environmental Change. 23 (1): 327–337. doi:10.1016/j.gloenvcha.2012.10.008 . Retrieved 7 July 2020.
