• Mountain ranges surround Mono Lake in California. Credit: University of Georgia

    How carbon is accounted around the globe for can be a tricky matter. Carbon moves from the land and sea into the atmosphere and back again. Too much in the atmosphere and we’ve got climate change. But figuring out where it’s all coming from is no small matter. Scientists at the University of Helsinki this week published a paper in the journal Geophysical Research Letters, highlighting a source of emissions previously undetected. Lakes, it turns out, can be a big contributor to atmospheric carbon load. Large volumes of carbon erode off the land into lakes and once there the carbon exchanges with the air above. If carbon emissions over lakes are ignored, which they have been, an important source of the globe’s carbon budget is undetected. The Finnish scientists took a peek above a boreal lake in their neck of

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  • Earth's early atmosphere of nitrogen, methane and carbon dioxide was hostile to life as we know it, but friendly to the first methane-loving bacteria. Astronomers modeled the history of Earth's atmosphere to learn what fingerprints to seek on alien worlds. This artist's rendering shows Earth at 4 billion years ago, before continents had formed and while our planet still suffered bombardment from asteroids and comets left over from the solar system's formation. Credit: David A. Aguilar (CfA)

    The world’s human population is expected to hit 7 billion people by the end of October. Almost no one is taking that number in as cause for celebration. In fact, 7 billion comes with quite a bit of angst, since 8 billion is projected in a mere 15 years and 9 billion by 2050, says the U.N. The U.N.’s assumption is that the world can absorb all these new people. But does the demographic forecast doesn’t square with the environmental one? Humanity long ago overshot its sustainability. And while the catastrophe envisioned by scholar Thomas Malthus has been repeatedly revived (remember dire warnings of the “Population Bomb” in the 1970s that failed to materialize?), climate change these days adds more cause for concern. Some experts foresee a bleaker picture in which climate change and limited natural resources, like arable land

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  • The new study suggests that the joining of North and South America changed the salinity of the Pacific Ocean and caused major ice sheet growth across the Northern Hemisphere.

    The world is awash in low-carbon technologies that aim to put the breaks on climate change. But perhaps a more limiting factor in solving the problem is the lack of “social technologies.” From politicians to everyday consumers to corporations, there seems to be a lack of incentives to act green. UK journalist John Whitfield nailed the issue on the head in the latest issue of the journal Nature Climate Change. Whitfield, who has a book coming out next month called, People Will Talk: The Surprising Science of Reputation, says in his essay that in addition to harnessing the sun or wind for the climate’s benefit, we should also harness the power of shame. There’s been a steady body of research showing how shame, or social reputation, can make a big mark on human behavior. The problem for the climate is

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  • As global warming increases precipitation in the Weddell Sea, sea-ice patterns are changing and a deep sea current is shrinking.

    The melting of the polar ice caps gets a lot of attention for global sea level rise. But another contributing factor to higher tides is groundwater depletion. More than 6 percent of the sea level rise in the last century is from the movement of land-locked water to the oceans. That’s according to a new study by the U.S. Geological Survey and published in the most recent edition of the journal Geophysical Research Letters. Groundwater depletion for human consumption and agricultural and industrial uses is known to have many negative outcomes, including land subsidence, a reduction in surface water as underground springs dry up, the depletion of wetlands, and threats to long term water supplies. Pumping groundwater to the surface also adds to sea levels as the water is used and then discharged into sewer systems and storm drains, which

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  • tropical frog extinction

    High latitude regions of the planet like the Arctic are experiencing the greatest warming.  But tropical areas, which see a much smaller temperature range during the year, are showing the most significant signs of warming. The warming signal in the tropics will likely exceed past temperature ranges in the next two decades. A global temperate increase of 1 degree Celsius is lower than all economically plausible emissions scenarios. But that one degree makes a huge difference in the tropics, and is outside the natural variability in temperatures. That’s according to a recent paper published in the journal Environmental Research Letters. Scientists at the Institute for Atmospheric and Climate Science in Zurich and NOAA Earth System Laboratory in Boulder were sifting through climate data and looking for signs of climate change on the local level. They evaluated what global temperature increase

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  • Fossil raindrops and meerkat

    What happens if the human population continues to grow and nothing much changes in the way we curb fossil fuel use? Climate models these days have largely focused on scenarios that assume some level of restraint on greenhouse emissions, with particular emphasis on the political goal of keeping global temperatures no higher than 2 degrees above pre-industrial levels.  But scientists at the National Center for Atmospheric Research in Boulder and the Institute for Atmospheric and Climate Science in Zurich have simulated scenarios that show the upper boundaries of future greenhouse gas emissions. In a paper published recently in the journal Environmental Research Letters, the scientists write that understanding these upper range scenarios is crucial for good decision-making about climate change. In one climate scenario, the human population grows from 6 to 11 billion by the end of the century, while

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  • These cliffs at Zumaia in Spain's Basque country date to the end of the
Cretaceous. Sediment layers in the cliffs can yield information about
changes in Earth's climate. 
Credit: PNAS / UC Berkeley

    It may seem that global politics will never align to respond seriously about climate change. But businesses see the bottom line and are acting accordingly. A new survey by the UK-based Carbon Disclosure Project finds that for the first time a majority of the world’s largest corporations have climate actions embedded as part of their business strategies. Companies in the Global 500 such as Philips Electronics, BMW, Bank of America and Sony, among others, comprise the 68 percent of respondents to the survey who say they’ve placed climate change at the heart of their business strategies. That’s a big jump above the 48 percent reported in 2010. These companies are also saying they are reducing greenhouse gas emissions. Why are many boardrooms now getting it? The survey attributes the rising consciousness around climate change to spikes in oil prices and

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  • Methane blanketing Earth. Credit: GISS, NASA

    Black carbon particles in the Western Pacific are at levels comparable to megacities like Houston and Los Angeles because they are floating widely throughout the atmosphere. These dark colored particles, which form from incomplete combustion, are one of the major contributors to climate change by absorbing solar radiation and by causing snow and ice to melt faster. The discovery is just one of a number that’s expected to come out of the far-reaching expedition called HIPPO (HAIPER Pole-to-Pole Observations), which ends this week. A project of a number of federal government agencies and universities, HIPPO involved a three-year series of research flights from the Arctic to the Antarctic that measured greenhouse gases and particles in the atmosphere that affect the Earth’s climate. The goal was to sample a broad range of molecules in the atmosphere to better understand where they

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  • The Filchner-Ronne shelf ice is part of the Antarctic ice shield, which expanded to its near-modern volume 14 million years ago. Photo: Ralph Timmermann, Alfred-Wegener-Institut

    About 50 percent of the world’s organic carbon stored in the soil is locked down in the frigid northern reaches of the Arctic, below an icy permafrost cap and in rich peat lands. If all that carbon were released, atmospheric CO2 concentrations could go up a whopping 660-870 parts per million. Global warming is gradually unlocking these Arctic carbon reserves. In a paper published recently in the Journal of Geophysical Research, University of Alaska, Fairbanks geophysicist Guido Grosse and colleagues tease out two forces acting on the Arctic carbon reserve. “Press” disturbances present a slow, persistent force on the carbon reserves. And “pulse” disturbances present rapid and extreme releases. The result is a complicated web of environmental implications for the Arctic and the globe. Among the most important “press” disturbances is the continual melt of Arctic permafrost, which until now

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  • TreesFallen

    A long time ago in Northern Europe, dense forest was converted to farmland and has remained so ever since. Now there’s a movement to reforest some of those lands in an effort to counteract climate change. But the picture is complicated. Farmland may not absorb much carbon, but it accumulates snow in the winter which reflects light back into space creating a cooling effect in the atmosphere. Dark-colored forests, on the other hand, absorb a lot of heat, but the vegetation also locks down carbon. So is it better to plant trees or not? Previous studies showed that farmland was a better mitigator of climate change in the Northern Europe than forests. But a new study out in the most recent edition of Geophysical Research Letters challenges that conclusion. Research led by Julia Pongratz at Stanford University found that you

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