Successfully confronting climate change is directly related to also reducing America's balance of payments and air pollution; it is also key to progress on helping the world's poor. "The Global Deal" provides an excellent source of information for moving forward. The author's credibility is vouched for by his having been Chief Economist at the World Bank from 2000-2003, first holder of the I. G. Patel Chair at the London School of Economics, Chair of the Grantham Institute for Climate Change and the Environment (2008- ), his election as an Honorary Fellow of the American Academy of Arts and Sciences, and his being recruited by Gordon Brown to conduct reviews on the economics of climate change and economic development.
The danger from climate change, says Stern, is not primarily in the added heat, but from water - an increase in the number and severity of storms, droughts, floods, and rising seal levels. A 5 degree C increase is estimated to be the limit that could be incurred without extreme damage - yet, it is the same change (opposite direction) that brought the extreme of last ice age 10,000 years ago.
Poor countries are the least responsible for the existing stock of greenhouse gases, yet get hit the earliest and hardest by their effects. China has overtaken the U.S. to become the world's largest producer of greenhouse gases; Indonesia and Brazil are third and fourth - mainly the result of deforestation and peat fires. Rich country populations represent about one in six today, by 2050 they will represent only one in nine. Thus, meeting the energy needs of the poor will be more essential than ever.
Stern cites estimates that the Amazon forests store about 10X the carbon emitted globally/year; those same forests store about 10X/acre as northern native forests.
Retention of Kyoto gases in the atmosphere is increasing at an increasing rate as emissions increase and the 'planet's absorptive capacity decreases. Between 1930-1950, it was about 0.5 ppm/year, doubling from 1950-1970, and doubling again from 1970-1990. The rate has reached 2.5 ppm/year in the last decade, and under business as usual, would reach 3-4 ppm for the first half of this century. At that point, temperature would further increase due to releases from methane escaping from thawing permafrost, etc.
Five hundred ppm is seen by many as "the safe limit;" we now are at 430, and adding 2.5/year. If world output grows slightly over 2%/year until 2050 it would be 2.5X the present level. To achieve stability at 500 ppm requires a 80% reduction in emissions/output unit. Major emission sources in 2000 include electricity and heat generation (27%), land use change and forestry - mostly deforestation and peat fires (18%), agriculture (13%), transportation (12%), and manufacturing and construction (11%).
About one-third of new power capacity installed in the U.S. 2007 was wind. Coal is attractive because of dependability (eg. night requirements are not a problem), security of supplies, and low costs.
The last time the world was 4-5 degrees C warmer was 30-50 million years ago when alligators lived near the North Pole.
Marginally sophisticated attempts at obfuscation focus only on the mean expected temperature increases in the short-term, rather than a longer horizon or possibility of higher increases. Some on the right see environmental causes as a Trojan Horse used by those who would like to regulate and control the economy; others on the left see the issue as an elitist one diverting attention from poverty. Regardless, the costs of change implies a large audience for arguing such change is not worth the cost, can be postponed, or is not necessary.
Achieving 500 ppm would cost about 2% of the world's GNP over the next half-century, estimates Stern. Seems like a bargain and good investment to me!
