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.
All forms of life that breathe oxygen—even ones that can't be seen with the naked eye, such as bacteria—must fight oxidants to live. These same oxidants also exist in the environment. But neutralizing environmental oxidants such as superoxide was a worry only for organisms that dwell in sunlight—in habitats that cover a mere 5% of the planet. Now researchers have discovered the first light-independent source of superoxide.
In an effort to determine if conditions were ever right on Mars to sustain life, a team of scientists has examined a meteorite that formed on the red planet more than a billion years ago. And although this team’s work is not specifically solving the mystery, it is laying the groundwork for future researchers to answer this age-old question.
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.
A NASA-funded sounding rocket mission will launch from an atoll in the Pacific in the next few weeks to help scientists better understand and predict the electrical storms in Earth's upper atmosphere These storms can interfere with satellite communication and global positioning signals.
Long-term exposure to air pollution may be linked to heart attacks and strokes by speeding up atherosclerosis, or "hardening of the arteries," according to a University of Michigan public health researcher and colleagues from across the U.S.
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.
The ability to determine the fate of charcoal is critical to knowledge of the global carbon budget, which in turn can help understand and mitigate climate change. However, until now, researchers only had scientific guesses about what happens to charcoal once it's incorporated into soil. They believed it stayed there. Surprisingly, the findings of a new study shows that most of these researchers were wrong.
Scientists at Lawrence Livermore National Laboratory and the University of California, Berkeley have discovered new materials to capture methane, the second highest concentration greenhouse gas emitted into the atmosphere. The research team performed systematic computer simulation studies on the effectiveness of methane capture using two different materials—liquid solvents and nanoporous zeolites.
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%.
Researchers have successfully measured reaction rates of a second Criegee intermediate, CH3CHOO, and proven that the reactivity of the atmospheric chemical depends strongly on which way the molecule is twisted. The measurements will provide further insight into hydrocarbon combustion and atmospheric chemistry.
Variations in nutrient availability in the world's oceans could be a vital component of future environmental change, according a research team. Their research reviews what we know about ocean nutrient patterns and interactions, and how they might be influenced by future climate change and other man-made factors. The authors also highlight how nutrient cycles influence climate by fuelling biological production.
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.
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.
A laboratory experiment at NASA's Jet Propulsion Laboratory, Pasadena, Calif., simulating the atmosphere of Saturn's moon Titan suggests complex organic chemistry that could eventually lead to the building blocks of life extends lower in the atmosphere than previously thought. The results now point out another region on the moon that could brew up prebiotic materials.
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.
For the first time, scientists measured the chemical diffusivity and viscosity of atmospheric organic particles, thanks to a new approach from scientists at Pacific Northwest National Laboratory, University of Washington, and Imre Consulting. The team doped atmospherically important organic nanoparticles, known as secondary organic aerosols, with tracer molecules and measured their diffusion rate as they slowly worked their way out of the particles. Knowing the diffusion rate, the scientists calculated the particle's viscosity.
Scheduled for launch in late 2013, the Mars Atmosphere and Volatile Evolution (MAVEN) mission will carry a sensitive magnetic-field instrument built and tested by a team at NASA’s Goddard Space Flight Center. Very little magnetic field traces remain on Mars, which is forcing NASA to eliminate all magnetic traces from its spacecraft. The magnetometer may help determine the history of the loss of atmospheric gases to space through time, providing answers about Mars’ climate evolution.
Certain bacteria can breathe iron like we breathe oxygen. Understanding how they do so will help researchers use the microbes for cleaning up soil contaminants, for trapping carbon dioxide, or for making batteries out of bacteria. Now, a team of researchers report that proteins on the surface of bacteria produce an electric current by simply touching a mineral surface, allowing them to breathe the iron in the rock.
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.
According to a recent study from Rice University and the U.S. Environmental Protection Agency, there is good news and better news about ground-level ozone in American cities. While dangerous ozone levels have fallen in places that clamp down on emissions from vehicles and industry, the report suggests that a model widely used to predict the impact of remediation efforts has been too conservative.
With data from 73 ice and sediment core monitoring sites around the world, scientists have recently reconstructed Earth's temperature history back to the end of the last Ice Age. The analysis reveals that the planet today is warmer than it's been during 70 to 80% of the last 11,300 years.