New paper finds Northern Rockies fire activity was highest when CO2 levels were ‘safe’
'Paper published in Geophysical Research Letters reconstructs annual area burned in Northern Rockies from 1626 to 2008 and finds the periods of greatest fire activity were in the early 1600's and during the period 1929-1945, both of which had 'safe' levels of CO2 below 350 ppm'
