05 Feb 2014:
Vast Forests and Frequent
Fires Were Key Causes of Ancient Warming
The release of volatile organic compounds from forests and smoke from wildfires had a far greater impact on global warming 3 million years ago than ancient atmospheric levels of carbon dioxide, a new study finds
. During the mid-Pliocene epoch, forests covered a much larger percentage of the planet, releasing large amounts of volatile organic compounds, according to Nadine Unger of the Yale School of Forestry & Environmental Studies. Those compounds are precursors to ozone and organic aerosols, which are both potent greenhouse gases. The dark foliage of the planet's abundant forests also absorbed large amounts of solar energy, another reason why the Pliocene was a relatively warm era even though atmospheric levels of CO2 were not exceptionally high. The research — based on earth-system modeling that used a supercomputer capable of processing 52 trillion calculations per second — provides evidence that dynamic atmospheric chemistry played an important role in past warm climates, underscoring the complexity of climate change, the authors explain in the journal Geophysical Research Letters
. "The discovery is important for better understanding climate change throughout Earth’s history ... and the role of forests in climate protection strategies," said Unger, who led the study.
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A look at how acidifying oceans could threaten the Dungeness crab, one of the most valuable fisheries on the U.S. West Coast. Watch the video.
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An aerial view of why Europe’s per capita carbon emissions are less than 50 percent of those in the U.S. View the photos.
An indigenous tribe’s deadly fight to save its ancestral land in the Amazon rainforest from logging. Learn more.
video series looks at the staggering amount of food wasted in the U.S. – a problem with major human and environmental costs. Watch the video.
Residents of the Chocó Rainforest in Ecuador are choosing to plant cacao over logging in an effort to slow deforestation.
Watch the video.
Tribal people and ranchers join together to stop a project that would haul coal across their Montana land. Watch the video.