At this time of year , many coastal New Englanders' last waking thought is of their air conditioners, the comfortable ballpark thickness of bedclothes having declined since January from a much a possible to less than a cotton blanket's one-third-inch loft.
This is in part because we have , since our forebears day , added a similar thickness of insulation outside our windows. Carbon dioxide is as effective in trapping radiant body warmth as eiderdown is in isolating us from the cold,, and while, brought to earth as a layer , the 260 parts per million of the gas in the air the Founders breathed would have been just two blankets thick , today with 380 parts per million in the air we are closing in on three- at this rate, by 2028, a full inch of CO2 will lay between us and the deep cold of outer space.
Since air pressure is roughly a kilogram per square centimeter , and there are a million milligrams in a kilogram, CO2's concentration ( 380 millionths by volume ) divided by its molecular weight (44) tell us how thick a layer it would form if separated from the air above us to form a blanket on the ground . Right now that thickness stands at 19.5 millimeters -- there are 25.4 to an inch,and as the blanket is thickening as fossil fuel is burned.At the present rate of CO2 growth some parts per million per year, in a few decades the absolute thickness of the cozy stuff will pass the one inch mark.
Some will hail this as a boon to chilly mankind , a sentiment easily defended on a cold winter's night, but come a Fourth Of July power brown out, cause for some to change their minds.