4.5.2 Financing
The way in which the costs of the project would be paid for is by countries or industries paying based on their emissions of metric tons of carbon due to GHGs. The basis for the emissions would include all sources of GHGs including food production and deforestation, not just electric power generation and transportation. Kyoto or a successor treaty would have to be modified to allow use of these “thermal credits” in lieu of emissions reductions or credits obtained under other existing mechanisms of the treaty.
According to the IPCC, the cumulative carbon dioxide emissions from 1990-2100 for the SRES scenario with forcings most similar to the ones previously used in our analysis (IS92a) are projected to be around 1500 GtC (171). Assuming carbon dioxide is 70% of total GHG forcing over this period, then total carbon equivalent emissions will be 2150 GtC. Over this period, this is an average of 19.5 GtC/yr. Assuming these are also the average annual emissions over the period 2010-2070 (1170 GtC), the figure of 19.5 GtC/yr can be used in calculating the cost per ton of the global albedo enhancement project.
The cost for the plastic cover installed in year 1 carried through to year 150 would be $17.1/ton, while the cost for plastic installed in year 30 would be $13.8/ton and in year 60, $10.3/ton (see Appendix B for details). Taking the average of the year 1 and year 60 costs, the average cost per ton over the 150-year period is $13.7. For purposes of further estimates, the figure $15/ton is used, an average of $117 billion/year. This is slightly higher than the $10/ton target the U.S. DOE has set for capture and sequestration of carbon emissions from electric power stations by 2015.
The estimate of $15/ton by 2010 in our proposed scheme compares very favorably with $100-300/ton for existing carbon management schemes proposed for electric power generation in 2003 and extremely favorably with schemes for other sectors for which there are no cost estimates, since there are no organized plans to reduce emissions from these sectors. In fact, it is very likely, come 2010 when this scheme may be ready for deployment, there may still be no alternative to offset most of the coming warming. In this case, this scheme’s costs should be compared against the expected environmental damage from climate change that will certainly be much more than the equivalent of $15/ton in carbon emissions.
The total and annual costs of offsetting emissions from individual sectors or industries would, of course, be lower than the maximum totals presented here. As examples, the annual and total lifetime (150-year) costs for the U.S. to meet its 2012 Kyoto target are approximately $8.5 billion and $1.27 trillion; to offset all forcing from 1750-2000, around $105.3 billion and $15.8 trillion. The cost for all U.S. electric power generation from 1750-2070 is approximately $11.4 billion and $1.7 trillion. These estimates are based on the area coverage required to achieve the corresponding forcing reduction for each case.
