350 Is The Most Important Number of Your Lifetime

Way back in December, and given the topic of this post that is indeed way back, James Hanson, coming in at number one atop Nixon's Cheny-Bush's enemy scientists list, made an alarming declaration: we have already exceeded the amount of atmospheric C02 necessary to maintain the planet as we know it. In fact, the planet as it has existed for the entire evolution and lifetime of the human species where the concentration of carbon in the atmosphere remained roughly 275 parts per million. But enough about homo sapiens, what were we talking about? Oh yes, the planet and the fate of all life on earth. The magic number is 350 parts per million atmospheric carbon dioxide and we are currently at 383ppm.

When Hansen presented a paper with his new research data and conclusions, Bill McKibben wrote a piece in the WaPo spreading the ultimatum that unless we reduce the amount of carbon dioxide in the atmosphere to 350 parts per million, "we will cause huge and irreversible damage to the earth." Until recently, scientists and policymakers focused on what would happen if that number doubled to 550 and whether or not we could curtail human production of carbon enough to stop short of that point. Yes we could, but with immense difficulty.

The big problem is "slow feedback" loops that amplify the rise in temperature caused by increased concentrations of greenhouse gases. Ice and snow reflect sunlight but when they ice sheets melt and recede, they leave exposed ground which absorbs more heat compounding the warming effect. And if that's too large or abstract for you, let's bring it down to human scale with this month's outbreak of dengue fever in Rio de Janeiro state, Brazil wherein the army established field hospitals to treat this epidemic affecting over 45,000 people since January or approximately twice the number of all cases in 2007. In addition to several factors that dominant health organizations point out, the Aedes aegypti mosquito likes a tropical climate and as the globe warms, its habitat will expand. And lucky for us *snark* ae. aegypti are diurnal, which means they are around day and night so I predict the next eco fashion trend to involve a fresh new choice in fabric, mosquito-netting. Oh those are poor people in the third world you say, so how about this nugget McKibben spoke about at an NYC event I attended the other night: glaciers melt into the oceans, oceans evaporate and rain down on farmers' fields flooding them to the point of stunting and delaying the production of food in Vermont (America) where McKibben is a scholar in residence at Middlebury College. Additionally, he says scientists are now beyond concerned, they are out and out panicked.

News this fall that Arctic sea ice was melting at an off-the-charts pace and data from Greenland suggesting that its giant ice sheet was starting to slide into the ocean had already begun to make even the revised estimate of 450ppm atmospheric C02 look too high. Hansen's paper co-authored with eight other climate scientists involved their team studying core samples taken from the bottom of the ocean, which allow C02 levels to be tracked from millions of years ago and are more accurate that theoretical modeling. They show that when the world began to glaciate at the start of the Ice Age about 35 million years ago, the concentration of CO2 in the atmosphere stood at about 450ppm. A new Ice Age not aversive enough for you, try a sea-level rise of at least a couple of meters this century according to Hansen.

The Guardian reports Hansen said his findings were not a recipe for despair since reserves of fossil fuels have been exaggerated, so an alternative source of energy will have to be rapidly put in place in any case. Also McKibben and colleagues, many of the same organizers behind last year's wildly successful Step It Up campaign, have got a new project to bring awareness to the need for bringing atmospheric carbon levels within range. The plan is to make the number 350 known by all around the globe, and as Arabic numerals are universal, they are a safe bet (to the extent they are not cause to get you on the terrorist no-fly list) for quickly reaching a lot of folks around the globe. Also, gravy on top is that, it just so happens, Middlebury College has both a leading environmental studies program as well as a world-renown Language School. The just launched 350.org already includes versioning in 12 languages. What's the number?