The Snowball Earth is a geohistorical hypothesis that proposes during one or more of Earth's icehouse climates, the planet's surface became nearly entirely frozen with no liquid oceanic or surface water exposed to the atmosphere. The most academically referred period of such global ice age is believed to have occurred sometime before 650 mya during the Cryogenian period, which included at least two large glacial periods, the Sturtian and Marinoan glaciation.
Keith Peter Shine FRS is the Regius Professor of Meteorology and Climate Science at the University of Reading. He is the first holder of this post, which was awarded to the university by Queen Elizabeth II to mark her Diamond Jubilee.
Global dimming is a decline in the amount of sunlight reaching the Earth's surface. It is caused by atmospheric particulate matter, predominantly sulfate aerosols, which are components of air pollution. Global dimming was observed soon after the first systematic measurements of solar irradiance began in the 1950s. This weakening of visible sunlight proceeded at the rate of 4–5% per decade until the 1980s. During these years, air pollution increased due to post-war industrialization. Solar activity did not vary more than the usual during this period.
Wallace "Wally" Smith Broecker was an American geochemist. He was the Newberry Professor in the Department of Earth and Environmental Sciences at Columbia University, a scientist at Columbia's Lamont–Doherty Earth Observatory and a sustainability fellow at Arizona State University. He developed the idea of a global "conveyor belt" linking the circulation of the global ocean and made major contributions to the science of the carbon cycle and the use of chemical tracers and isotope dating in oceanography. Broecker popularized the term "global warming". He received the Crafoord Prize and the Vetlesen Prize.
The faint young Sun paradox or faint young Sun problem describes the apparent contradiction between observations of liquid water early in Earth's history and the astrophysical expectation that the Sun's output would be only 70 percent as intense during that epoch as it is during the modern epoch. The paradox is this: with the young Sun's output at only 70 percent of its current output, early Earth would be expected to be completely frozen, but early Earth seems to have had liquid water and supported life.
In climate science, longwave radiation (LWR) is electromagnetic thermal radiation emitted by Earth's surface, atmosphere, and clouds. It may also be referred to as terrestrial radiation. This radiation is in the infrared portion of the spectrum, but is distinct from the shortwave (SW) near-infrared radiation found in sunlight.
Mikhail Ivanovich Budyko was a Soviet and Russian climatologist and one of the founders of physical climatology. He pioneered studies on global climate and calculated temperature of Earth considering simple physical model of equilibrium in which the incoming solar radiation absorbed by the Earth's system is balanced by the energy re-radiated to space as thermal energy.
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.
Nir Joseph Shaviv is an Israeli‐American physics professor. He is professor at the Racah Institute of Physics of the Hebrew University of Jerusalem.
Syun-Ichi Akasofu is the founding director of the International Arctic Research Center of the University of Alaska Fairbanks (UAF), serving in that position from the center's establishment in 1998 until January 2007. Previously he had been director of the university's Geophysical Institute from 1986.
This is a list of climate change topics.
Solar radiation modification (SRM), or solar geoengineering, refers to a range of approaches to limit global warming by increasing the amount of sunlight that the atmosphere reflects back to space or by reducing the trapping of outgoing thermal radiation. Among the multiple potential approaches, stratospheric aerosol injection is the most-studied, followed by marine cloud brightening. SRM could be a temporary measure to limit climate-change impacts while greenhouse gas emissions are reduced and carbon dioxide is removed, but would not be a substitute for reducing emissions.
Stratospheric aerosol injection is a proposed method of solar geoengineering to reduce global warming. This would introduce aerosols into the stratosphere to create a cooling effect via global dimming and increased albedo, which occurs naturally from volcanic winter. It appears that stratospheric aerosol injection, at a moderate intensity, could counter most changes to temperature and precipitation, take effect rapidly, have low direct implementation costs, and be reversible in its direct climatic effects. The Intergovernmental Panel on Climate Change concludes that it "is the most-researched [solar geoengineering] method that it could limit warming to below 1.5 °C (2.7 °F)." However, like other solar geoengineering approaches, stratospheric aerosol injection would do so imperfectly and other effects are possible, particularly if used in a suboptimal manner.
Owen Brian Toon is an American professor of atmospheric and oceanic sciences. He is a fellow at the Laboratory for Atmospheric and Space Physics (LASP) at the University of Colorado Boulder. He received an A.B. in physics at the University of California, Berkeley in 1969 and a Ph.D. in physics at Cornell University in 1975 under Carl Sagan. His research interests are in cloud physics, atmospheric chemistry, and radiative transfer. He also works on comparing Earth and other planets such as Venus.
Robert Donald Cess was a professor of atmospheric sciences at Stony Brook University. He was born in Portland, Oregon. Cess earned his bachelor of science degree in mechanical engineering from Oregon State University and his master's degree from Purdue University in Indiana in 1956. He received a Ph.D. from the University of Pittsburgh in 1959. He is a recognized leader in the fields of climate change and atmospheric radiation transfer. His research interests involved modeling of climate feedbacks that can either amplify or diminish global climate change, and interpreting surface and satellite remote sensing data.
David W. Keith is a professor in the Department of the Geophysical Sciences at the University of Chicago. He joined the University of Chicago in April 2023. Keith previously served as the Gordon McKay Professor of Applied Physics for Harvard University's Paulson School of Engineering and Applied Sciences (SEAS) and professor of public policy for the Harvard Kennedy School at Harvard University. Early contributions include development of the first atom interferometer and a Fourier-transform spectrometer used by NASA to measure atmospheric temperature and radiation transfer from space.
Nicola Scafetta is a research scientist and at the University of Napoli Federico II. He was formerly at the ACRIM Lab group and an adjunct assistant professor in the physics department at Duke University. His research interests are in theoretical and applied statistics and nonlinear models of complex processes. He is notable for having controversial views on climate change.
Novim is a non-profit group at the University of California, Santa Barbara that organizes teams for objective scientific study of global issues and identification options for addressing the concerns, based upon a collaborative problem-solving approach used in the field of physics.
Patterns of solar irradiance and solar variation have been a main driver of climate change over the millions to billions of years of the geologic time scale.
Michael Ghil is an American and European mathematician and physicist, focusing on the climate sciences and their interdisciplinary aspects. He is a founder of theoretical climate dynamics, as well as of advanced data assimilation methodology. He has systematically applied dynamical systems theory to planetary-scale flows, both atmospheric and oceanic. Ghil has used these methods to proceed from simple flows with high temporal regularity and spatial symmetry to the observed flows, with their complex behavior in space and time. His studies of climate variability on many time scales have used a full hierarchy of models, from the simplest ‘toy’ models all the way to atmospheric, oceanic and coupled general circulation models. Recently, Ghil has also worked on modeling and data analysis in population dynamics, macroeconomics, and the climate–economy–biosphere system.
