Yale Environment 360: The amount of carbon dioxide in the atmosphere increased by 2.67 parts per million in 2012, marking the second-biggest jump since levels were first recorded in 1959 and decreasing the chances that the planet will avoid a dangerous temperature increase of 3.6 degrees F (2 C) or higher, U.S. scientists say. The new data, collected in Mauna Loa, Hawaii, suggests that levels of heat-trapping CO2 are now just under 395 parts per million (ppm) and could hit 400 ppm within two years, according to the National...