Carbon Dioxide and Methane level rose sharply in 2007.
Last year alone global levels of atmospheric carbon dioxide, the primary driver of global climate change, increased by 0.6 percent, or 19 billion tons. Additionally methane rose by 27 million tons after nearly a decade with little or no increase.
The burning of coal, oil, and gas, known as fossil fuels, is the primary source of increasing carbon dioxide emissions.
last year’s carbon dioxide increase means 2.4 molecules of the gas were added to every million molecules of air, boosting the global concentration to nearly 385 parts per million (ppm). Pre-industrial carbon dioxide levels hovered around 280 ppm until 1850. Human activities pushed those levels up to 380 ppm by early 2006.
Since 2000, annual increases of two ppm or more have been common, compared with 1.5 ppm per year in the 1980s and less than one ppm per year during the 1960s.
Methane levels rose last year for the first time since 1998. Methane is 25 times more potent as a greenhouse gas than carbon dioxide, but there’s far less of it in the atmosphere—about 1,800 parts per billion. When related climate affects are taken into account, methane’s overall climate impact is nearly half that of carbon dioxide.
Rapidly growing industrialization in Asia and rising wetland emissions in the Arctic and tropics are the most likely causes of the recent methane increase, said scientist Ed Dlugokencky from NOAA’s Earth System Research Laboratory.
”We’re on the lookout for the first sign of a methane release from thawing Arctic permafrost,” said Dlugokencky. “It’s too soon to tell whether last year’s spike in emissions includes the start of such a trend.”
Levels of methane (a far more potent greenhouse gas than CO2) rose last year for the first time since 1998, perhaps an early indication of thawing permafrost.
Permafrost, or permanently frozen ground, contains vast stores of carbon. Scientists are concerned that as the Arctic continues to warm and permafrost thaws, carbon could seep into the atmosphere in the form of methane, possibly fueling a cycle of carbon release and temperature rise.
from NOAA news