During the week of May 13th, the CO2 level at the Mauna Loa Observatory in Hawaii topped 400 ppm repeatedly. Daily levels of CO2 can vary due to weather, and there are seasonal trends as well.
Russian heat wave had both manmade and natural causes
The heat wave that struck western Russia in summer 2010, killed 55,000 people, broke July temperatures records and caused $15 billion in damage. A new study concludes the devastating heat wave had human and natural causes. Soaring temperatures were found to be within the natural range for a Russian summer, but due to human-induced climate change, the chance of such an extreme heat wave has tripled over the past several decades. For more details, see the AGU Press Release from February 21st, 2012.
