As campaigning for the November presidential election moves forward, President Barack Obama and his Republican challenger Mitt Romney spelled out their interpretations on one issue in a bit more detail than usual. To Science Debate, Obama identifies climate change as one of the most pressing concerns of the era and lists the steps he has taken during his term to mitigate the effects climate change. Mitt Romney, meanwhile, agrees that "human activity contributes to that warming, and that policymakers should therefore consider the risk of negative consequences." But Romney offers a caveat: "However, there remains a lack of scientific consensus on the issue -- on the extent of the warming, the extent of the human contribution, and the severity of the risk." Neither Romney nor Obama suggest specific policies (subscription) to slow or guard against the effects of climate change.
More than 20,000 high-temperature records have been broken so far this year in the United States. A new study indicates that the number of species grew when global temperatures increased during periods in the geologic past. The timescales involved, roughly 500 million years, may cancel out any benefits from the rising temperatures.
Weather events linked to climate change could affect agricultural production significantly and cause dramatic food-price spikes within two decades. In their report "Extreme Weather, Extreme Price," Oxfam researchers suggest extreme weather events such as the droughts and floods have been previously underestimated. More frequent extreme weather events will pose a more serious threat to the world's poor, leading to millions of deaths from malnutrition among the world's poorest if governments do not act on climate change. Another study on climate change and the food supply looks at whether it would be possible to increase global yields while reducing the use of agricultural inputs like water and fertilizers. They found that overall output of 17 of the world's crops could be increased by 45 to 70 percent by closing the "yield gap"--that is, by reducing the tendency of farmers in many regions to produce less than their potential.
Arctic Sea Ice Melt Hits New Low
Arctic Sea ice hit a new record low of 3.6 million square kilometers--down from 4.2 million square kilometers Aug. 24. That leaves 25 percent of the original ice sheet intact, which means more summer sunlight is absorbed by a warmer Arctic Ocean. The melt, the BBC reported, is like adding 20 years of carbon dioxide emissions to the atmosphere. A Washington Post editorial argues that the extent of the recent losses "should shock Congress and the president into more aggressive action."
A large reservoir of close to 4 billion tons of methane may lie beneath the Antarctic ice sheet. Release of the methane--a greenhouse gas 25 times more potent than carbon dioxide--has the potential to accelerate global warming. "There's a potentially large pool of methane hydrate in part of the Earth where we haven't previously considered it," Jemma Wadham, professor of Glaciology at the U.K.'s University of Bristol and lead author the study in the journal Nature. "Depending on where that hydrate is, and how much there is, if the ice thins in those regions, some of that hydrate could come out with a possible feedback on climate."
Oil and gas reserves in the Arctic may not be as significant as many think, because extracting these reserves is cheaper elsewhere. Prices for these resources must remain high for it to be profitable to recover petroleum resources in the region, a new study said.
Three-Quarters of Americans Favor New Fuel Economy Standards
As one of the key architects of a new U.S. Environmental Protection Agency rule doubling fuel economy by 2025 retires, a poll from the Consumer Federation of America found that 74 percent of Americans support the new standards. Most said higher fuel economy was important in their next vehicle purchase. The New York Times reported because California can set its own vehicle emissions standards, it has special place at the table in the negotiations over fuel economy standards. Some say the rule could give a significant boost to sales of electric vehicles, whose performance is measured in "miles per gallon equivalent" in order to account for electrical power in terms of fuel economy.
Meanwhile, India has approved a $4.1 billion plan to increase the number of hybrid and electric vehicles in the country. The goal: 6 million vehicles by 2020.
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.