The obvious conclusion is that the only practical way to avoid climate catastrophe is to terminate emissions from the largest fossil fuel source: coal, the dirtiest of the fossil fuels. If coal emissions are phased out between 2010 and 2030, global fossil fuel emissions would begin to fall rapidly as shown in the chart below.
The rate of emissions (shown in billions of tons of carbon on the left and in percent of 2008 emissions on the right) depends upon how much oil and gas is used. The (red) curve showing larger emissions is based on the assumption that the larger reserve estimates of EIA are valid and all of the CO2 is emitted to the atmosphere. These emission scenarios have been converted to atmospheric CO2 amounts using a simplified version of the Bern carbon cycle model.
The next chart shows that atmospheric CO2 would peak at only ~400 ppm in ~2025, if the IPCC oil and gas reserves are accurate and if coal emissions are phased out uniformly over the period 2010-2030.
If, however, the EIA oil and gas reserves are accurate (and if coal emissions are phased out), atmospheric CO2 will peak early in the second half of this century and atmospheric CO2 will be about 30 ppm higher than with the IPCC reserve estimates.
The EIA reserve estimates may be realistic if we choose to go after every last drop of oil by drilling off-shore, on public lands, in the Arctic National Wildlife Reserve, and in the deepest oceans, for example. With these larger reserves exploited, future generations, including our grandchildren, likely will be forced to seek ways to extract that extra 30 ppm of CO2 from the atmosphere. In the referenced paper we discuss the costs of air capture and disposal of CO2, estimating a cost of about $200 per ton of carbon. Thus the cost of removing 30 ppm would be about $12 trillion dollars, a burden that would be passed to our descendants.
The primary implication, however, concerns coal. The reason that CO2 peaks at only 400-425 ppm in these scenarios is the assumption that coal emissions will be phased out linearly between 2010 and 2030. Such a scenario is technically possible, but only with policies that lead to availability of appropriate alternative technologies and incentives for using them.
We must move beyond fossil fuels at some point. Why not do it sooner, for the benefit of our children?
Political meetings may produce lofty goals for reduced carbon dioxide emissions by some future date. But these are of practically no significance if the goals and the actions of the nations are inconsistent with geophysical constraints.
For example, I spoke with a German Minister. We found that we were in good agreement with the startling conclusion that we are already moving into dangerous levels of atmospheric CO2. Yet Germany plans to build more coal-fired power plants. His rationalization was that they could “tighten the carbon cap” on cap and trade.
I pointed out that, if coal emissions continued, that cap would somehow have to force Russia to leave its oil in the ground. I asked how he would convince Russia to do that.
He had no answer.
The overwhelming practical requirement, for the sake of future generations, humanity itself, and the other species on the planet, is phase-out of coal emissions over the next 20 years.
The correct fundamental approach is a rising price on carbon emissions, as needed to achieve these objectives. The Waxman-Markey bill fails the test in the same way as the German plans: it builds in approval of new coal-fired power plants. There is no need for these plants except to enrich utility and coal special interests – they are included only because the monstrous 1400-page absurdity was hatched in Washington after energetic insemination by special interests.