For decades, scientists have used sophisticated instruments and computer models to predict the nature of droughts. The majority of these models have steadily predicted an increasingly frequent and severe global drought cycle. But a recent study from a team of researchers in the United State and Australia suggests that one of these widely used tools—the Palmer Drought Severity Index (PDSI)—may be incorrect.
As recently as 5,000 years ago, the Sahara was a verdant landscape, with sprawling vegetation and numerous lakes. The Sahara’s “green” era likely lasted from 11,000 to 5,000 years ago, and is thought to have ended abruptly. Now researchers have found that this abrupt climate change occurred nearly simultaneously across North Africa.
According to a new study by scientists funded by the National Science Foundation (NSF) and at the National Oceanic and Atmospheric Administration (NOAA), clouds over the central Greenland Ice Sheet last July were "just right" for driving surface temperatures there above the melting point. The 2012 melt illustrates the often-overlooked role that clouds play in climate change. Current models don’t do enough, says researchers, to account for their effects.
In 2011, Lake Erie experienced a record-breaking algae bloom that began in the lake's Western region in mid-July and eventually covered an area of 230 square miles. At its peak in October, the bloom had expanded to more than 1,930 square miles, three times greater than any other bloom on record. According to recent research, the bloom was triggered by long-term agricultural practices coupled with extreme precipitation, followed by weak lake circulation and warm temperatures.
Researchers from several universities, AT&T Labs, and the American Museum of Natural History have built new models that show a widespread redistribution of Arctic vegetation. They say their findings predict a massive “greening” in the Arctic, as much as 50% in over the next few decades. This transition will help accelerate climate warming, they add.
Lawrence Berkeley National Laboratory recently hosted an international workshop that brought together top climatologists, computer scientists, and engineers from Japan and the United States to exchange ideas for the next generation of climate models as well as the hyper-performance computing environments that will be needed to process the data from those models. It was the 15th in a series of such workshops that have been taking place around the world since 1999.
It’s not entirely clear what caused the end-Triassic extinction, although most scientists agree on a likely scenario: Over a relatively short period of time, massive volcanic eruptions from a large region known as the Central Atlantic Magmatic Province (CAMP) spewed forth huge amounts of lava and gas, including carbon dioxide, sulfur and methane. Now, a research team has determined that these eruptions occurred precisely when the extinction began, providing strong evidence that volcanic activity did indeed trigger the end-Triassic extinction.
According to new research, models of carbon dioxide in the world’s oceans need to be revised. Trillions of plankton near the surface of warm waters are far more carbon-rich than has long been thought global marine temperature fluctuations could mean that tiny microbes digest double the carbon previously calculated.
With the planet heating up, many scientists seem fairly certain some weather elements like hurricanes and droughts will worsen. But tornadoes have them stumped. As the traditional tornado season nears, scientists have been pondering a simple question: Will there be more or fewer twisters as global warming increases?
Geoengineering, the use of human technologies to alter the Earth's climate system has emerged as a potentially promising way to mitigate the impacts of climate change. But such efforts could present unforeseen new risks. That inherent tension, argue two professors, has thwarted both scientific advances and the development of an international framework for regulating and guiding geoengineering research.
Clouds can both cool the planet, by acting as a shield against the sun, and warm the planet, by trapping heat. But why do clouds behave the way they do? And how will a warming planet affect the cloud cover? Lawrence Berkeley National Laboratory scientist David Romps has made it his mission to answer these questions.
An international research team has just published a study showing that, as the cover of snow and ice in the northern latitudes has diminished in recent years, the temperature over the northern land mass has increased at different rates during the four seasons. This has caused temperatures and vegetation at northern latitudes to more and more resemble those found several degrees of latitude farther south.
A research team led by the University of Colorado Boulder had been looking for clues about why Earth did not warm as much as scientists expected between 2000 and 2010. They now think the culprits are hiding in plain sight—dozens of volcanoes spewing sulfur dioxide. The study results essentially exonerate Asia, including India and China, two countries that are estimated to have increased their industrial sulfur dioxide emissions by about 60% from 2000 to 2010 through coal burning.
New research on a mineral called molybdenite by a team led by Robert Hazen at Carnegie's Geophysical Laboratory provides important new insights about the changing chemistry of our planet as a result of geological and biological processes. Analysis of the mineral showed that concentrations of rhenium, a trace element that is sensitive to oxidation reactions, increased significantly—by a factor of eight—over the past three billion years.
Volcanoes are well known for cooling the climate. But just how much and when has been a bone of contention among historians, glaciologists, and archeologists. Now a team of atmosphere chemists, from the Tokyo Institute of Technology and the University of Copenhagen, has come up with a way to say for sure which historic episodes of global cooling were caused by volcanic eruptions.
Ancient carbon trapped in Arctic permafrost is extremely sensitive to sunlight and, if exposed to the surface when long-frozen soils melt and collapse, can release climate-warming carbon dioxide gas into the atmosphere much faster than previously thought.
A new Rice University-led study finds the real estate mantra “location, location, location” may also explain one of Earth’s enduring climate mysteries. The study suggests that Earth’s repeated flip-flopping between greenhouse and icehouse states over the past 500 million years may have been driven by the episodic flare up of volcanoes at key locations where enormous amounts of carbon dioxide are poised for release into the atmosphere.
Heat-trapping gases from U.S. power plants fell 4.6% in 2011 from the previous year as plants burned less coal, the biggest source of greenhouse gas pollution, according to a new government report. The report, released Tuesday by the Environmental Protection Agency, said power plants remain the largest stationary source of carbon dioxide and other greenhouse gases that trigger global warming.
A team of U.S. ice-coring scientists and engineers in Antarctica, funded by the National Science Foundation (NSF), have recovered from the ice sheet a record of past climate and greenhouse gases in the atmosphere that extends back 68,000 years.
In a first-of-its-kind feat of science and engineering, a research team has successfully drilled through 800 m (2,600 feet) of Antarctic ice to reach a subglacial lake and retrieve water and sediment samples that have been isolated from direct contact with the atmosphere for many thousands of years. The samples may contain microbes from an ecosystem isolated for thousands of years, with implications for the search for life elsewhere in extreme environments.
A new study that provides surprising details on changes in Earth's climate from more than 100,000 years ago indicates that the last interglacial—the period between "ice ages"—was warmer than previously thought and may be a good analog for future climate, as greenhouse gases increase in the atmosphere and global temperatures rise.
Human beings around the world are observing and accurately detecting changes in their local climates, according to a new study led by Yale University researchers. The finding provides the first global evidence for the phenomenon and could have meaningful implications for attempts to combat climate change, they say.
Environmental groups hailed President Barack Obama's warning about climate change in his second inauguration speech, but said the president's words will soon be tested as he decides whether to approve the Keystone XL oil pipeline from Canada. Obama pledged Monday to respond to what he called "the threat of climate change," saying the failure to do so would be a betrayal of the nation's children and future generations.
Warmer temperatures due to climate change could cause soils to release additional carbon into the atmosphere, thereby enhancing climate change—but that effect diminishes over the long term. The new study sheds new light on how soil microorganisms respond to temperature and could improve predictions of how climate warming will affect the carbon dioxide flux from soils.
Scientists at the Universities of York and Leeds have made a significant discovery about the cause of the destruction of ozone over oceans. They have established that the majority of ozone-depleting iodine oxide observed over the remote ocean comes from a previously unknown marine source.