At the end of the last Ice Age, as the world began to warm, a brief pulse of biological productivity in the Pacific Ocean gave rise to large numbers of phytoplankton, foraminifera and other creatures. Researchers have hypothesized that iron sparked this surge of ocean life, but a new study determines instead that “perfect storm” of nutrients and light spurred the bloom.
The length of the satellite record for the Greenland and Antarctic ice sheets is currently too short to tell if the recently reported speed-up of ice loss will be sustained in the future or if it results from natural processes, according to a new study. Sheets are losing are about 300 billion tons of ice each year, but no consensus has emerged about the cause of this recent increase in mass loss.
Studies have long predicted that plants would begin to use water more efficiently, that is, lose less water during photosynthesis, as atmospheric carbon dioxide levels rose. However, an international research team doing work at the Harvard Forest Long-Term Ecological Research site has found that forests across the globe are losing less water than expected and becoming even more efficient at using it for growth.
President Barack Obama's push to fight global warming has triggered condemnation from the coal industry across the industrial Midwest, where state and local economies depend on the health of an energy sector facing strict new pollution limits. But such concerns stretch even to New England, an environmentally focused region that long has felt the effects of drifting emissions from Rust Belt states.
In a speech Tuesday at Georgetown University, Barack Obama is expected to announce he's issuing a presidential memorandum to launch the first-ever federal regulations on carbon dioxide emitted by existing power plants, moving to curb the gases blamed for global warming despite adamant opposition from Republicans and some energy producers.
A “cold snap” 116 million years ago triggered a similar marine ecosystem crisis to the ones witnessed in the past as a result of global warming, according to recently published research. The international study confirms the link between global cooling and a crash in the marine ecosystem during the mid-Cretaceous greenhouse period.
A recent study is the first to show that corals are not able to fully acclimate to low pH conditions in nature. The results are from a study of corals growing where underwater springs naturally lower the pH of seawater. The coral doesn’t die, but the acidity reduces the density of coral skeletons, making coral reefs more vulnerable to disruption and erosion.
An international team of scientists has developed crop models to better forecast food production to feed a growing population—projected to reach 9 billion by mid-century—in the face of climate change. The team recently unveiled an all-encompassing modeling system that integrates multiple crop simulations with improved climate change models.
If the climate continues to evolve as predicted by the Intergovernmental Panel on Climate Change, the United States stands little to no chance of satisfying its current biofuel goals, according to a new study by Rice Univ. and the Univ. of California, Davis. The recently published study suggests that in 40 years, a hotter planet would cut the yield of corn grown for ethanol in the U.S. by an average of 7%.
As ice sheets melted during the deglaciation of the last ice age and global oceans warmed, oceanic oxygen levels decreased and "denitrification" accelerated by 30 to 120%, a new international study shows, creating oxygen-poor marine regions and throwing the oceanic nitrogen cycle off balance. By the end of the deglaciation, however, the oceans had adjusted to their new warmer state and the nitrogen cycle had stabilized.
From Virginia to Florida, there is a prehistoric shoreline that, in some parts, rests more than 280 feet above modern sea level. The shoreline was carved by waves more than 3 million years ago—possible evidence of a once higher sea level, triggered by ice-sheet melting. But new findings by a team of researchers reveal that the shoreline has been uplifted by more than 210 feet, meaning less ice melted than expected.
An international team of researchers may have found what cause a dramatic cooling near the end of the last major Ice Age more than 12,000 years ago. The recently published study, which involved the study of rock melted into carbon spherules, describes evidence of a major cosmic event near the end of the Ice Age. The ensuing climate change forced many species to adapt or die.
According to research taking place at Lawrence Livermore National Laboratory, the distortion of the ancient shoreline and flooding surface of the U.S. Atlantic Coastal Plain are the direct result of fluctuations in topography in the region and could have implications on understanding long-term climate change, according to a new study.
The old saying that "what goes up must come down" doesn't apply to carbon dioxide pollution in the air, which just hit an unnerving milestone. The chief greenhouse gas was measured Thursday at 400 parts per million in Hawaii, a monitoring site that sets the world's benchmark. This was last matched about 2 million years ago, or more, and is more than modern humans have ever encountered.
Researchers studying the origin of cirrus clouds have found that these thin, wispy trails of ice crystals are formed primarily on dust particles and some unusual combinations of metal particles—both of which may be influenced by human activities. The findings are important, scientists say, because cirrus clouds cover as much as one-third of the Earth and play an important role in global climate.
University of Manchester scientists, writing in Nature Geoscience, have shown that natural emissions and manmade pollutants can both have an unexpected cooling effect on the world’s climate by making clouds brighter. Clouds are made of water droplets, condensed on to tiny particles suspended in the air. When the air is humid enough, the particles swell into cloud droplets.
The growing global demand for energy, combined with a need to reduce emissions and lessen the effects of climate change, has increased focus on cleaner energy sources. But what unintended consequences could these cleaner sources have on the changing climate? Researchers at Massachusetts Institute of Technology now have some answers to that question, using biofuels as a test case.
A team from the Smithsonian and the University of Rhode Island has found unsuspected linkages between the oxidation state of iron in volcanic rocks and variations in the chemistry of the deep Earth. Their detailed spectroscopic work has uncovered chemical trends that not only run counter to predictions from recent decades of study, they belie a role for carbon circulating in the deep Earth.
The Environmental Protection Agency has dramatically lowered its estimate of how much of a potent heat-trapping gas leaks during natural gas production. This shift has major implications for a debate that has divided environmentalists, which is whether the recent boom in fracking helps or hurts the fight against climate change.
Recent work by University of Washington climate scientists have provided new insights into how to keep a drink cold on a hot day. Their work shows that, in sultry weather, condensation on the outside of a canned beverage doesn’t just make it slippery: those drops can provide more heat than the surrounding air, meaning the drink would warm more quickly.
The most comprehensive evaluation of temperature change on Earth’s continents over the past 1,000 to 2,000 years indicates that a long-term cooling trend—caused by factors including fluctuations in the amount and distribution of heat from the sun, and increases in volcanic activity—ended late in the 19th century.
A new global-scale modeling study that takes into account nitrogen—a key nutrient for plants—estimates that carbon emissions from human activities on land were 40% higher in the 1990s than in studies that did not account for nitrogen. Most existing models used to estimate global emissions changes based on land use do not have the ability to model nitrogen limitations on plant regrowth.
Using a new laboratory geochemical technique to analyze heavy isotopes of carbon and oxygen in fossil snail shells, scientists have gained insights into an abrupt climate shift that transformed the planet nearly 34 million years ago. At that time, the Earth switched from a warm and high-carbon dioxide "greenhouse" state to the lower-carbon dioxide, variable climate of the modern "icehouse" world.
A Purdue University-led team of researchers discovered sunlit snow to be the major source of atmospheric bromine in the Arctic, the key to unique chemical reactions that purge pollutants and destroy ozone. The team's findings suggest the rapidly changing Arctic climate—where surface temperatures are rising three times faster than the global average—could dramatically change its atmospheric chemistry.
New research indicates that cutting emissions of certain pollutants can greatly slow sea level rise this century. Scientists focussing on emissions of four heat-trapping pollutants—methane, tropospheric ozone, hydrofluorocarbons, and black carbon—found that reductions these pollutants that cycle comparatively quickly through the atmosphere could temporarily forestall the rate of sea level rise by roughly 25 to 50%.