- The concentration of carbon dioxide (CO2) in the atmosphere was 383 parts per million (ppm) in 2007, 37% over pre-industrial revolution concentrations (280 ppm), higher than any concentration over the last 650,000 years, and “probably” higher than any concentration in the last 20 million years.
- Actual emissions of CO2 over the period of 2000-2007 are higher than the highest (worst-case) IPCC emissions scenario.
- Growth in emissions from cement and coal power plants in developing nations (mostly India and China) now account for more than 50% of all CO2 emissions and a related stagnation in carbon intensity (amount of GDP per unit of carbon).
- The amount of CO2 extracted from the air by natural carbon sinks is rising, but slower than CO2 emissions. In addition, natural carbon sinks have lost efficiency over the last 50 years.
- The GPC concludes that all of the above combine to produce stronger CO2-driven climate forcing, and sooner than the IPCC estimates.
So, then, what does this all mean?
First off, this means we need to start decarbonizing human civilization sooner, decarbonize faster, and decarbonize to an even lower level than the IPCC AR4 target (emissions peaking between 2015 and 2020 and 50% below 1990 levels by 2050). The worst-case IPCC-SRES scenario has humanity dumping about 2,500 Gt more carbon into the atmosphere than 1990 levels by 2100, and we’re now running above that worst-case scenario. For reference, the 383 ppm of CO2 in the Earth’s atmosphere currently represents about 812 GtCO2, or about 221 GtC. 2,500 GtC represents an 11x increase in CO2 concentration, or 4,328 ppm – 0.4% of the atmosphere – by 2100. CO2 hasn’t been that high since between 50 and 60 million years ago, when mammals began to take over from the extinct dinosaurs. And remember, the GPC says we’re emitting more than that scenario already. Can anyone honestly say they think that’s a good idea?
Second, with China and India dominating emissions in the developing world, we have to get them both on board to cut their emissions dramatically. Yes, historically, the United States and Europe are responsible for the existing problem. That doesn’t matter any more, and the developing world can’t be permitted to make the same mistakes the developed world did. Yes, that’s paternalistic – suck it up and deal. If the developing nations don’t like it, then there’s the good, old-fashioned carrot-and-stick approach – cut CO2 emissions dramatically and we’ll give you technologies and aid and all that good stuff, fail to cut emissions a lot and you’ll find yourself facing carbon tariffs and cut out of every international organization and market you depend on to grow your economy. Yes, it’ll hurt the entire world to have China’s dirt-cheap labor unavailable, and that would suck for everyone. But some other market will pop up, maybe in Eastern Europe, the rest of Southeast Asia, Africa, or South America. It’ll happen, and neither China nor India would like it to happen to them.
Alternately, we in the developed world could admit that our complaints about China’s CO2 emissions are hypocritical bullshit given that China’s coal power plants are feeding our appetite for products and our economies. Attach the price of all those carbon emissions to the products we buy and I bet this would take care of itself in short order, and probably without causing China to panic and threaten war over a collapsing economy.
Third, the carbon intensity of the world economy needs to drop a lot, and that means a dramatic boost in efficiency throughout all sectors. The nice thing is that efficiency increases pay for themselves in nearly all cases, but not necessarily in a timely manner. Every city in the world needs to do what Berkeley, California is trying to do – reduce the cost of entry for every single energy efficiency improvement, from solar panels to lower electricity consumption to ground heat pump installations. And no new home should be built without every available technology for energy efficiency already installed. Of course, that requires a change in how new construction is financed, but if you can solve the problem for existing construction being retrofitted, you can solve it for new construction as well.
I’m not convinced that the total decarbonization of the U.S. economy in ten years is viable, but if we don’t start decarbonizing not just ourselves, but everyone, really soon, we’re screwed. How screwed is yet to be seen, but I for one think that the purchase of a little economic insurance is a good idea, especially when the first few years of work will result in a global profit.