Carbon dioxide concentration in the air increased by 2.4 parts per million last year, according to the National Oceanic and Atmospheric Administration reported Wednesday. Methane has increased at a more rapid rate as well. Concern has grown in recent years about these gases as many atmospheric scientists are becoming increasingly concerned that the i accumulation is causing the Earth's temperature to rise. Ultimately, these gases have the potential to cause climate changes. Global concentration of carbon dioxide is now nearly 385 parts per million. This compares with preindustrial carbon dioxide levels, which hovered around 280 ppm until 1850. Human activities pushed those levels up to 380 ppm by early 2006.
Fast growing industrialization in Asia and rising wetland emissions in the Arctic and tropics are the most likely causes of the recent methane increase, according to NOAA. Methane in the atmosphere rose by 27 million tons last year after nearly a decade with little or no increase. Methane is 25 times more potent as a greenhouse gas than carbon dioxide and scientists are becoming more concerned.