Emissions scenarios

Nuclear power plants in Cattenom, France.

Stefan Kühn

Recently Updated
Arctic Sea-Ice, Polar Bear Habitat and Greenhouse Gas Emissions Last Updated on 2010-12-22 00:00:00 Projected Losses of Arctic Sea-Ice and Polar Bear Habitat May Be Reduced If Greenhouse Gas Emissions are Stabilized Sea-ice habitats essential to polar bears would likely respond positively should more curbs be placed on global greenhouse gas emissions, according to a modeling study published in the journal, Nature.  The study, led by the U.S. Geological Survey, included university and other federal agency scientists. The research broke new ground in the “tipping point” debate in the scientific community by providing evidence that during this century there does not seem to be a tipping point at which sea-ice loss would become irreversible.  The report does not affect the decision made by the U.S. Fish and Wildlife Service in 2008 to list the polar bear as a threatened species.    This study builds and expands upon studies... More »
IPCC Emission Scenarios Last Updated on 2010-12-16 00:00:00 Climate forecasting requires insight into the predictability of forcing factors that influence Earth’s climate. External forcing factors run the gamut in terms of predictability. The orbital variations of obliquity, eccentricity, and precession follow patterns set by the law of gravity that should continue indefinitely. Sunspot numbers oscillate with an 11-year period. In contrast, external factors such as comets crashing into Earth seem to be exceedingly rare, random occurrences and therefore are often ignored in forecasts or treated as a very slight possibility. Internal forcing factors also run the gamut. Albedo, the extent to which Earth’s surface reflects incoming solar electromagnetic radiation, declines as global warming melts snow or ice packs and raises the sea level. Albedo increases with deforestation and desertification and with greater cloud cover. GCMs... More »
Lecture: Stephen Schneider Climate Change Mitigation and Adaptation Video Last Updated on 2010-10-07 00:00:00 This video is of a lecture that Stephen Schneider presented a number of times. It covers climate change from a risk perspective, discussing the underlying science, uncertainties, and implications of different possible decisions. Here is it captured with many (although not all) of his graphics. It is a well organized, evenly presented lecture that carefully differentiates questions of "what we know" from "what we should do." It presents data and modelling at a level appropriate for undergraduates. More »
Nuclear power Last Updated on 2010-05-10 00:00:00 Nuclear power is the generation of electricity from controlled reactions within the nucleii of atoms that release energy used to boil water, the steam from which drives a turbine to generate electricity . All commercial nuclear plants presently rely upon nuclear fission reactions. As of 2010, approximately 14 percent of the world's electricity was derived from nuclear power, chiefly centered in the United States (with 31% of the world's total nuclear power capacity), France (16%), and Japan (10%). The International Atomic Energy Agency (IAEA) reports that, as of November 21, 2012, there are 437 nuclear power reactors in operation in 30 countries, plus Taiwan. Another 64 reactors under construction in 14 countries which if operational today would increase the worldwide electrical generation capacity of nuclear power by 17%. One hundred and forty reactors have been... More »