PLEA Network

25 November 2015, New Matilda, Halting Climate Change Means More Than Cutting Carbon. With the Paris climate talks just around the corner a focus on carbon dioxide is not enough. Geoff Russell explains. With yet another in the seemingly infinite sequence of climate summit conferences looming it’s time to take stock of what’s been happening over the past 25 years. But I’ll be taking stock properly, which means not being CO2 centric. Focusing exclusively on CO2 is rather like focusing on protein when thinking about nutrition: it’s simply silly. It’s been seven years since Barry Brook and I wrote an article about the misleading nature of the so-called “carbon dioxide equivalence” factor used to aggregate methane emissions in Greenhouse Inventories. This isn’t a priority claim; many understood the problem before us. Among the first was Kirk Smith of the University of California, Berkeley. Smith is an expert in air quality, among other things, and was the first to measure and understand the impact of indoor cooking smoke on health in India. Globally, it kills people, mainly women and children, by the hundreds of thousands every year. He’s also been tackling the problem in a practical way by spinning off students and companies designing and building cleaner cookers. Smith’s latest work, with main author Manish Desai, calculates a metric called the International Natural Debt (IND) which is a better than average measure who is responsible for our climate woes. Their study uses national emission inventories and greenhouse gas equations to calculate precisely the impact of emissions on radiative forcing (that’s just jargon for warming). In effect, while they don’t include all the components of a full climate model, they do at least account for the full impact of methane on warming. Their estimate, based on the best inventory data is that anthropogenic methane, on its own, contributes about half of our net warming influence on the climate. In technical language methane is about ~850 mW/m2 of the net ~1600 mW/m2 of anthropogenic radiative forcing. That makes methane a big deal. Even more importantly, reductions in methane have an almost immediate cooling impact. Read More here