If we want to stabilize atmospheric CO2 at 450 ppm around 2050 -- the minimum necessary, which still might carry major impacts -- we need to achieve at least 2 percent average annual net reductions in emissions, globally, starting in two years. Not only do the near term emissions reductions matter the most, but it will get easier, not harder, as we go along. Solar PV and solar thermal are likely to become cheaper than new coal plants in a decade or so. They will also probably become cheaper than wind around the same time, and together these resources will make it possible to eliminate about three quarters of fossil generation.
It may be possible to exceed the 2 percent rate. But the only way to know that is to achieve 2 percent first. Nothing weaker than 2 percent is particularly worth talking about, and anything stronger is very hard to achieve. Also, any strategy to reduce CO2 emissions must address ongoing growth. While there are many reasons to believe the rate of new growth will change, as it has done historically, it is at present about 1.5 percent per year. Thus a 2 percent annual net reduction in today's world means a 3.5 percent gross reduction.
This series discusses the implications of this goal for the U.S. electric industry.
