• Cloud plumes from cracks of open water in the Arctic sea ice cover. Image credit: University of Hamburg, Germany

    Arctic sea ice is melting at a fast and steady rate. Or is it?  Scientists at the National Center for Atmospheric Research (NCAR) have discovered that the polar ice might temporarily expand for as a long as a decade before succumbing to longer term melting trends. In a study published this week in the journal Geophysical Research Letters, the scientists explain this surprising conclusion. Using computer simulations, they found that the amount of sea ice loss over the 20th century could not be attributed to climate change alone. About half of it was the result of natural forces acting on the climate. The findings demonstrate that climate change offers an only partial picture to the iciness of Arctic seas. Wind patterns, for example, could have a cooling affect. And sometimes these natural forces outstrip the warming effects of climate change

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  • Carbon cenospheres are tiny, carbon-rich particles that form when coal and heavy fuel are heated intensely. Scientists have now learned that cenospheres can form in the wake of asteroid impacts, too.
Credit: Mark Harvey / Indiana University

    Hydroelectricity is often posed as a carbon-free energy source. But get this. Some hydroelectric dams Рparticularly in the tropics Рare even worse than fossil fuel power plants. A study published in the Journal of Geophysical Research examined greenhouse gas emissions coming from a large hydroelectic plant in Brazil: the Balbina Dam along the Uatuṃ River in the central Amazon basin. This dam flooded out more than 900 square miles of lush, tropical rainforest when it was built in 1987 Рthe first knock to its green credentials. On the whole, dams throughout the world contribute about 4 percent of anthropogenic sources of CO2. But according to the study, led by the National Institute of Amazonian Research in Brazil, very few tropical reservoirs were included in that assessment, making dams a potentially worse source of power than has been

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  • Near spacecraft, white crater on asteroid Eros. The lighter material is either fresh or from some unknown weathering process.

    Experts in the field of “climate communications” (yes, there is one), say this summer’s record-breaking temperatures across the country will have little long term impact once snowy weather sinks in this winter. Yes, people are that ADD when it comes to having a weather memory. Part of the confusion is that as weather changes, all the vagaries can chart people off course and keep them from seeing the bigger picture of climate. Now, if sweltering summers become the norm, or the expectation, it’s possible that people will begin to face how the climate is dramatically changing. And that’s just the kind of perspective that’s most accurate when it comes to understanding climate change. Climatologist Heidi Cullen has written a new book – The Weather of the Future: Heat Waves, Extreme Storms, and other Scenes from a Climate Changed Planet. In

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  • Cloud plumes from cracks of open water in the Arctic sea ice cover. Image credit: University of Hamburg, Germany

    In the late summer of 2007, lightening struck a remote corner of the Arctic on Alaska’s North Slope and burned for three months. The tundra soil there was dry because the permafrost, which normally encapsulates the carbon-rich soil in an icy sealant, had melted. The fire burned until October snowfalls put it out, but left a char the size of Cape Cod – some 400 square miles- and large enough to see from space. Michelle Mack, a biologist from the University of Florida, and Syndonia Bret-Harte, of the University of Alaska-Fairbanks, wondered how much carbon had been released during that long, hot burn. In a paper published this week in the journal Nature, they concluded that the carbon loss from this one fire was “unprecedented.” The amount of carbon that had been released into the atmosphere was the equivalent of

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  • Warming Arctic unleashing toxic chemicals

    A decade after nations banded together to ban some of the most persistent toxic chemicals, they are now leaching back out into the environment as the planet warms. In a study published in the July 24 online edition of the journal Nature Climate Change, researchers led by the Air Quality Research Division of Environment Canada examined concentrations of so-called “persistent organic pollutants” (POPs) at two Arctic monitoring stations in Svalbard, Norway and Canada. These long-lasting pollutants, known as the”dirty dozen,” include DDT, which was used for decades for pest control in farming and for public health, and PCBs, used in coolants and as plasticizers in paints and cements. Both were banned in the 2001 international Stockholm Convention because of adverse health and environmental impacts. Since the early 1990s levels of POPs have been decreasing as nations phased out their uses.

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  • Spotlight on Venice: Climate change a wash in the City of Water

    Ahh, Venice – the City of Water. Built on a lagoon along the Adriatic Sea, there must be a looming disaster in store for this lovely, sinking city in the face of climate change. Right? That was the harsh verdict of the Intergovernmental Panel on Climate Change (IPCC). But new research is questioning that conclusion. The frequency of storm surges– known by Venetians as “Acqua Alta”– is expected to drop 30 percent by the end of this century. That’s according to research led by Alberto Troccoli from the Commonwealth Scientific and Industrial Research Organisation in Canberra, Australia and published in the most recent edition on the journal Nature Climate Change. Under climate change, weather patterns in the Mediterranean buffer the Northern Adriatic from the ill affects of extreme tides. Weather data on storm surges from 1958-1997 back this up. A

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  • Impacts of climate change felt way into future

    The delay, or lag time, in the Earth’s climate system means that the full impacts of global warming will be felt long into the future. Well past our lifetimes, even. Atmospheric warming is followed by ocean warming is followed by a melting of polar ice sheets is followed by sea level rise. Scientists are trying to predict this new, warmer state by looking into the record of past eras of climate change. In a study out of the University of Arizona, researchers found that melting ice sheets had a greater impact on sea level rise than the thermal expansion of the oceans during the previous interglacial period 125,000 years ago. At that time, the sea level exceeded today’s by 26 feet. But only 1.5 feet could be attributed to thermal expansion of ocean water, the vast majority by melting sea

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  • Gray whales a model in climate adaptation

    In the time since California gray whales existed, the Earth has gone through more than 40 cycles of warming and cooling. Many species have been impacted and have even died out, but the gray whale has persisted for 250 million years. How did the gray whale survive? The gray whales, it turns out, may be a model in how a species can adapt and change during dramatic swings in the Earth’s climate. In the modern era, whaling has been the biggest threat to the gray whale survival, and in fact the species has rebounded to 22,000 individuals from a low of 1,000 in the past 75 years of conservation. But prior to human arrival, the whales faced dramatic changes in its feeding grounds due to climate change. During the last Ice Age (150,000-200,000 years ago), the expanding glaciers drew down

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  • Could farmers be a solution to climate change?

    Here’s a bit of hope amongst the doom and gloom of climate change. Set aside for a moment the massive engineering feat that would be required of pumping CO2 into underground storage tanks. That idea is going who knows where. A potentially viable solution to restoring carbon back into the earth resides with simple changes in the way we farm. A piece in Discover magazine, Could Dirt Help Health the Climate?, outlines the way agriculture is both a problem and a solution to climate change. Ohio State soil scientist Rattan Lal says in the piece that the world’s soils could soak up 13 percent of the CO2 in the world today — the equivalent of removing every bit from the atmosphere since 1980. Disruptive farming practices like slash and burn, fertilizing, ploughing, and overgrazing have sent massive amounts of carbon

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  • California premium wines a victim of climate change

    The cost of averting climate change is often argued as a reason to do nothing. But climate change also has severe economic consequences. Among them: a nice, cool glass of premium California chardonnay. A new Stanford University study reports that by 2040 the amount of land suitable for growing high value wines in Northern California could shrink by half as a result of higher temperatures. That would take a severe blow to the country’s wine industry. California produces 90 percent of the nation’s wine production, valued at $18.5 billion in 2010. The study, published in the June 30 edition of the journal Environmental Research Letters, was based on an average global temperature increase of 1.8 degrees Fahrenheit, which is considered a relatively conservative estimate and the limit needed to avert catastrophic impacts. That temperature increase is actually on the low

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  • If routine weather ravages U.S. economy, what about climate change?

    Most people well know the effects of weather. During a thunderstorm, you curl up in bed rather than shop. Flights get cancelled when a snowstorm hits. A long dry spell ruins a summer’s cucumber crop. The National Center for Atmospheric Research (NCAR) estimates that routine weather events cost the U.S. economy $485 billion a year, as much as 3.5 percent of the country’s GDP.  In a study that will be published in this month’s issue of the Bulletin of the American Meteorological Society the scientists used economic modeling techniques to analyze the sensitivity of the U.S. economy to temperature and precipitation. With 70 years of weather records across the U.S. they were able to establish weather variability patterns and compare them to economic indicators for various sectors of the economy. The results show that some industries are particularly hard hit

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  • Early warning of climate ‘tipping points’ is possible

    A climate ‘tipping point’ occurs when a small change triggers a cascading set of catastrophes that upsets the entire climate system for a long time.  Examples? The melting of the Greenland ice sheet trigger accelerated sea level rise, a die back of the Amazon rainforest removes a crucial atmospheric carbon sink, and an alteration of the ocean conveyor belt shuts down the Atlantic Gulf stream. What if you could predict a ‘tipping point’? Almost like the arrival of a hurricane or a tsunami? Scientists at the University of Exeter in the UK believe it’s possible to come up with early warning indicators of an approaching tipping point. You wouldn’t be able to avert the tipping point — it would be far too late for that. But societies might be able to mitigate the worst of its impacts. In a paper

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  • Atlantic waters rising at fastest rate in 2,000 years

    The sea level rise off the U.S. Atlantic shoreline is rising faster than any time in the past 2,000 years, according to a new study published this week. Since the 19th century, sea level has shot up more than 2 millimeters per year on average, far faster than other periods of global temperature change. Yale University-led scientists came to that conclusion by reconstructing the first continuous sea-level rise rates for the past two millennia and then comparing it to variations in global temperature. They used tiny fossils — foraminifera — that were preserved in sediment cores in coastal North Carolina salt marshes. The age of the cores was estimated with radiocarbon dating. The core samples were then tested against tide-gauge measurements and then corrected against the vertical movement of the land. The researchers found a fairly stable sea level from

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  • Can species adapt to climate change within decades?

    Do organisms have the ability to adapt to climate change on a timescale of decades? A study published in the recent online journal Proceedings of the Royal Society B set out to test that question with the little West Coast tidepool copepod, Tigriopus californicus, which normally shows an ability to tolerate wide ranges in temperatures. University of California at Davis lead author Morgan Kelly brought the little critters into a lab, selecting eight populations native within a range of 17 degrees latitude. She then reared 10 generations of each population under differing water temperatures to test the force of evolution and see which would survive. The results showed only two of the 10 able to adapt to higher temperatures. In particular, the northern populations lacked the capacity to acclimate to the temperatures found in the populations in the southern range.

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  • Summer heat hitting new “normal” under climate change

    Climate change may  take some of the joy out of summertime. Imagine sunbathing, picnic-ing, or camping in an extreme heat wave. Such temperatures may become the new “normal” in the coming decades, particularly in the tropics and the Northern Hemisphere. That’s according to research out of Stanford University, which analyzed more than 50 climate model simulations of 21st century temperatures under elevated greenhouse gas levels. “According to our projections, large areas of the globe are likely to warm up so quickly that, by the middle of this century, even the coolest summers will be hotter than the hottest summers of the past 50 years,” said the study’s lead author, Noah Diffenbaugh, in a Stanford University press release. The research is to be published later this month in the journal Climate Change Letters. The scientists found that the upward trend has

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