Natural emissions and man-made pollutants have an unexpected effect; they make clouds brighter and have a cooling effect on the world's climate.
A quick primer: 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. It has been known for some decades that the number of these particles and their size control how bright the clouds appear from the top, controlling the efficiency with which clouds scatter sunlight back into space. A major challenge for climate science has been trying to understand and quantify these effects, which have a major impact in polluted regions.
Rainfall over the Hawaiian Islands has been declining since 1978.
Is the drying trend due to global warming? Yes, says a team of researchers who found that climate models don't have enough resolution to capture the diverse rainfall pattern over Hawaii, where dry and wet areas often lie only a mile or even less apart, and so devised a method called 'statistical downscaling.'
They first got a take on the effects of the general drying trend on local heavy-rain days by reanalyzing observations from 1978 to 2010 at 12 rain-gauge stations spread throughout the islands. Studying hundreds of weather patterns during such days, they identified the typical atmospheric circulation patterns in the North Pacific that favor heavy rains over Hawaii.
Thermoelectric power plants interact with climate, hydrology, and aquatic ecosystems while rivers serve as "horizontal cooling towers" — but at a cost to the environment, says a new analysis.
While the United States is now back at early 1990s levels of CO2 emissions, thanks to a switch to natural gas in the energy sector and a moribund economy, that doesn't apply to Asia. The middle class in China alone has a population that exceeds the entire USA and they all want, and are getting, cars and air conditioners and a better life and the emissions to go along with it. Globally, greenhouse gas emissions have continued to rise but warming, the telltale sign of climate change, has not.
Since 2000, global warming has tapered off and virtually no one in the climate science community predicted that could happen.
An analysis of how carbon is trapped and released by iron-rich volcanic magma offers clues about our early atmospheric evolution and also that of other terrestrial bodies.
The composition of a planet's atmosphere starts far beneath the surface. When mantle material melts to form magma, it traps subsurface carbon. As magma moves upward toward the surface and pressure decreases, that carbon is released as a gas. On Earth, carbon is trapped in magma as carbonate and degassed as carbon dioxide, a greenhouse gas that helps Earth's atmosphere trap heat from the sun. But how carbon is transferred from underground to the atmosphere in other planets — and how that might influence greenhouse conditions — wasn't well understood.
Why didn't the Earth warm as much as estimates and numerical models projected would happen between 2000 and 2010? A new paper says now thinks the culprits are hiding in plain sight; they are dozens of volcanoes spewing sulfur dioxide.
Climate change causing every weather event enjoyed the kind of fallacious media coverage in late 2012 it hadn't gotten since 2006 - it remains bad science. While short-term weather is notoriously volatile, climate is more of an average weather pattern over a long period of time. This dichotomy provides the analytical framework for scientific thinking about atmospheric variability, including climate change.
Donald Wuebbles, a professor of atmospheric sciences at the University of Illinois at Urbana-Champaign, is going to do the thing the IPCC wishes people would not do; attribute local weather events to climate change.
The hurricanes and droughts like we had in 2012 will be more frequent in future U.S. five-day forecasts, as will other extreme weather events, and it's because of human-driven climate change he argues today at the AAAS meeting in Boston. In the 1950s, the number of days that set record high temperatures was equal to the number of days that set record low temperatures. By the 2000s, the United States was twice as likely to see a record high as a record low.
New satellite images show that the ozone hole over Antarctica in 2012 was the smallest seen in the past decade. Long-term observations show that Earth’s ozone has been strengthening. The ozone sensor on Europe’s MetOp weather satellite continues the long-term monitoring of atmospheric ozone started by its predecessors on the ERS-2 and Envisat satellites.
In the ongoing culture war among climate scientists, climate scientologists and climate deniers, few things stands out like the effect of volcanoes.
Volcanoes are well-known for cooling the climate but how much has been unclear, leading to radically differing claims and interpretations. Atmospheric chemists from the Tokyo Institute of Technology and the University of Copenhagen say that patterns of isotopes found in ancient volcanic sulfur trapped in ice cores, and patterns due to stratospheric photochemistry, are a way to say for sure which historic episodes of global cooling were caused by volcanic eruptions.