Parts of ancient Antarctica were as warm as today’s California coast, and polar regions of the southern Pacific Ocean registered 21st-century Florida heat, according to scientists using a new way to measure past temperatures. The findings underscore the potential for increased warmth at Earth’s poles and the associated risk of melting polar ice and rising sea levels, the researchers said.
Few Americans question that smoking causes cancer. But they express bigger doubts as concepts that scientists consider to be truths get further from our own experiences and the present time, an Associated Press-GfK poll found. Americans have more skepticism than confidence in global warming, the age of the Earth and evolution and have the most trouble believing a Big Bang created the universe 13.8 billion years ago.
Fish living on coral reefs where carbon dioxide seeps from the ocean floor were less able to detect predator odor than fish from normal coral reefs, according to a new study. The study confirms laboratory experiments showing that the behavior of reef fishes can be seriously affected by increased carbon dioxide concentrations in the ocean.
A 32-year study of subarctic forest moths in Finnish Lapland suggests that scientists may be underestimating the impacts of climate change on animals and plants because much of the harm is hidden from view. The study analyzed populations of 80 moth species and found that 90% of them were either stable or increasing throughout the study period, from 1978 to 2009.
Since the discovery of the Antarctic ozone hole, scientists, policymakers and the public have wondered whether we might someday see a similarly extreme depletion of ozone over the Arctic. But a new Massachusetts Institute of Technology study finds some cause for optimism: Ozone levels in the Arctic haven’t yet sunk to the extreme lows seen in Antarctica, because international efforts to limit ozone-depleting chemicals have been successful.
The cost of keeping global warming in check is "relatively modest," but only if the world acts quickly to reverse the buildup of heat-trapping gases in the atmosphere, the head of the U.N.'s expert panel on climate change said Sunday. Such gases, mainly carbon dioxide from the burning of fossil fuels, rose on average by 2.2% a year in 2000-2010.
The rise and fall of acid rain is a global experiment whose results are preserved in the geologic record. By analyzing samples from the Greenland ice sheet, Univ. of Washington atmospheric scientists found clear evidence of the U.S. Clean Air Act. They also discovered a link between air acidity and how nitrogen is preserved in layers of snow.
The U.N.'s expert panel on climate change is under pressure this week as it considers whether geoengineering should be part of the tool-kit that governments use to keep global warming in check. Drafts leaked before the conference only mentioned one of the proposed options, removing carbon dioxide from the air and storing it underground. But some countries support solar radiation management as well.
After concluding that global warming almost certainly is man-made and poses a grave threat to humanity, the U.N.-sponsored Intergovernmental Panel on Climate Change, or IPCC, is meeting next week in Berlin to chart ways in which the world can curb the greenhouse gas emissions that scientists say are overheating the planet. It is also trying to give estimates on what it would cost.
Far beneath the surface of the ocean, deep currents act as conveyer belts, channeling heat, carbon, oxygen and nutrients around the globe. A new study by the Univ. of Pennsylvania’s Irina Marinov and Raffaele Bernardello and colleagues from McGill Univ. has found that recent climate change may be acting to slow down one of these conveyer belts, with potentially serious consequences for the future of the planet’s climate.
The frustrated attempts of a Univ. of California, Los Angeles graduate student to quantify the amount of water draining from Greenland's melting ice sheet led him to devise a new way to measure river flows from outer space, he and his professor report in a new study. The new approach relies exclusively on the measurements of a river's width over time, which can be obtained from freely available satellite imagery.
A new analysis of satellite data reveals a link between dust in North Africa and West Asia and stronger monsoons in India. The study shows that dust in the air absorbs sunlight west of India, warming the air and strengthening the winds carrying moisture eastward. This results in more monsoon rainfall about a week later in India.
According to new research, the ice-free season across the Arctic is getting longer by five days per decade. New analysis of satellite data shows the Arctic Ocean absorbing ever more of the sun’s energy in summer, leading to an ever later appearance of sea ice in the autumn. In some regions, autumn freeze-up is occurring up to 11 days per decade later than it used to.
In recent years, palm oil production has come under fire from environmentalists concerned about the deforestation of land in the tropics to make way for new palm plantations. Now there is a new reason to be concerned about palm oil’s environmental impact, according to researchers at the Univ. of Colorado Boulder.
Volcanic eruptions in the early part of the 21st century have cooled the planet, according to a study led by Lawrence Livermore National Laboratory. This cooling partly offset the warming produced by greenhouse gases. Despite continuing increases in atmospheric levels of greenhouse gases, and in the total heat content of the ocean, global-mean temperatures at the surface of the planet have shown relatively little warming since 1998.
As a range of climate change mitigation scenarios are discussed, Univ. of Washington researchers have found that the injection of sulfate particles into the atmosphere to reflect sunlight and curb the effects of global warming could pose a severe threat if not maintained indefinitely and supported by strict reductions in greenhouse gas emissions.
Methane, a key greenhouse gas, has more than doubled in volume in Earth's atmosphere since 1750. Its increase is believed to be a leading contributor to climate change. But where is the methane coming from? Research by a California Institute of Technology atmospheric chemist suggests that losses of natural gas—our "cleanest" fossil fuel—into the atmosphere may be a larger source than previously recognized.
The release of volatile organic compounds from Earth’s forests and smoke from wildfires 3 million years ago had a far greater impact on global warming than ancient atmospheric levels of carbon dioxide, a new Yale Univ. study finds. The research provides evidence that dynamic atmospheric chemistry played an important role in past warm climates, underscoring the complexity of climate change and the relevance of natural components.
The latest observations of Jakobshavn Glacier show that Greenland’s largest glacier is moving ice from land into the ocean at a speed that appears to be the fastest ever recorded. Researchers from the Univ. of Washington and the German Space Agency measured the speed of the glacier in 2012 and 2013.
Insects may thrive in the warmer average temperatures predicted by climate models but are threatened by greater temperature variation also anticipated in many areas around the globe, a Yale Univ.-led study predicts. Scientists have tested the impact of temperature on 38 species of insects. The team coupled that data with historic climate data and climate projections for 2050 to 2059 in order to assess effects of temperature variability.
Scientists studying the atmosphere above Barrow, Alaska, have discovered unprecedented levels of molecular chlorine in the air, a new study reports. Molecular chlorine, from sea salt released by melting sea ice, reacts with sunlight to produce chlorine atoms. These chlorine atoms are highly reactive and can oxidize many constituents of the atmosphere including methane and elemental mercury.
Although few people live in the Western tropical Pacific Ocean region, the remote waters there affect billions of people by shaping climate and air chemistry worldwide. Next week, scientists will head to the region to better understand its influence on the atmosphere—including how that influence may change in coming decades if storms over the Pacific become more powerful with rising global temperatures.
Their effect on the surface of the ocean is negligible, producing a rise of just inches that is virtually imperceptible on a turbulent sea. But internal waves, which are hidden entirely within the ocean, can tower hundreds of feet, with profound effects on the Earth’s climate and on ocean ecosystems.
Pine Island Glacier is one of the biggest routes for ice to flow from Antarctica into the sea. The floating ice shelf at the glacier’s tip has been melting and thinning for the past four decades, causing the glacier to speed up and discharge more ice. Understanding this ice shelf is a key for predicting sea-level rise in a warming world.
Researchers at the Univ. of Utah have discovered a new aquifer in the Greenland Ice Sheet that holds liquid water all year long in the otherwise perpetually frozen winter landscape. The aquifer is extensive, covering 27,000 square miles and could figure significantly in understanding the contribution of snowmelt and ice melt to rising sea levels.