The National Oceanic and Atmospheric Administration (NOAA) announced last week that carbon dioxide concentrations at the Mauna Loa Observatory in Hawaii surpassed the milestone 400 parts per million for a sustained period. NOAA has since revised the figure -- on the basis of computer analysis -- saying its May 9 readings actually remained fractions of a point below the historic level, coming in at 399.89. A second monitoring program run by the Scripps Institute for Oceanography, The New York Times reports, continues to show a level of 400.8 parts per million for the same period. The numbers, scientists said, are a reminder of the long-term trend in greenhouse gases.
"The last time in the Earth's history when we saw similar levels of CO2 in the atmosphere was probably about 4.5 million years ago when the world was warmer on average by three or four degrees Celsius than it is today," said Professor Sir Brian Hoskins, director of the Grantham Institute for Climate Change at the Imperial College London. "There was no apparent ice sheet on Greenland, sea levels were much higher, and the world was a very different place."
A first draft of the congressionally mandated National Climate Assessment shares more data on how the climate is changing; the final version is due out in early 2014. Among the highlights: the average temperature in the U.S. has increased by nearly 1.5 degrees Fahrenheit since 1895, and sea levels are expected to rise another 1 to 4 feet this century. Another study, which looked at 50,000 common animals and plants, says climate change could lead to the loss of more than half of these plants and one third of the animals.
McCarthy Gets Go Ahead
After boycotting the first hearing a week ago, Republican lawmakers agreed to show up to vote today on whether to move the nomination for Gina McCarthy to head the U.S. Environmental Protection Agency to the full Senate. The Senate Environment and Public Works Committee voted 10-8 along party lines to move McCarthy forward in the process. No date has been set for the floor vote, and Sen. Roy Blunt still maintains a hold on McCarthy's nomination over a dispute to repair the levee system on the Mississippi River.
Natural Gas Exports, Ethanol Topics of Debate
The boom in domestic production of natural gas has lowered prices and stirred debate regarding the export of the resource. A decision by the Obama administration on whether to approve applications for some 20 natural gas export terminals could come in "weeks and not months," David Leiter, president of ML Strategies LLC, told Bloomberg. If all were approved, facilities could ship nearly 41 percent of the total U.S. production of natural gas this year and lead to further increases in hydraulic fracturing. This week, the Senate Energy and Natural Resources Committee held the first of a series of forums on natural gas. Up next week: exports.
Meanwhile, a new House bill seeks to modify the renewable fuel standard (RFS) to let natural gas-based ethanol qualify as a renewable. Currently, the rule limits eligible feedstocks to renewable sources such as corn, soybeans and switchgrass.
Rainforest Losses Could Affect Energy Output, Agriculture
Two new studies in the journals Proceedings of the National Academy of Sciences and Environmental Research Letters look at threats to the Amazon rainforest. The first finds extensive deforestation will leave less water in nearby rivers to run the hydropower dams that countries such as Brazil are investing billions of dollars to create. Scientists estimate that Brazil's controversial Bel Monte Dam -- one of the world's largest hydropower projects -- could deliver roughly 30 percent less power if forest loss continues. The loss is equivalent to the energy consumption of 4 million Brazilians.
Making more land available in the Amazon rainforest for farming could actually produce fewer "wins" for the agricultural sector, according to the Environmental Research Letters work. Why? Loss of trees not only reduces the capacity of the Amazon to act as a natural carbon sink, but also increases temperature and decreases precipitation. "These climate feedbacks, usually ignored in previous studies, impose reduction in precipitation that would lead agricultural expansion in Amazonia to become self-defeating: the more agriculture expands, the less productive it becomes," researchers said. Google and Carnegie Mellon share a time lapse look at deforestation's effect from 1984 to 2012.
The Climate Post offers a rundown of the week in climate and energy news. It is produced each Thursday by Duke University's Nicholas Institute for Environmental Policy Solutions.