I checked the Mauna Loa Observatory’s monthly CO2 concentration today and was a little surprised to see that October’s concentration was higher than September’s. This has happened in prior years, so nothing terribly odd is going on. It mostly has to do with natural processes not lining up neatly with our arbitrary calendar system.
In any event, October 2010’s concentration was measured to be 387.17ppm. That’s a rise of 0.37ppm since September’s average.
It could also mean that 2010’s average concentration might be above 390ppm for the first time in recorded history. Or it could just come painfully close to doing so and 2010 could be the last year that the concentration remained below 390ppm. Through October, 2010’s average CO2 concentration is now 389.925ppm. The rise in average monthly values from September to October will continue through November and December. Recent years saw November’s concentration ~1.4ppm higher than October’s and December’s concentration ~1.5ppm higher than November’s. If those trends hold true this year, 2010 would come in just under 390ppm for the year: 389.9ppm.
Please keep in mind that leading climatologists have recommended 350ppm concentration as the likely threshold beyond which major consequences from global warming occur. We must reduce our concentrations back under 350ppm as soon as possible if we want to keep global average temperatures from rising less than 2C this century. The higher the concentration goes, the higher the average temperature will be by century’s end.