A previous post on GW was done in 2005. This is the first of two new posts on Global Warming.
There are three instrumentalities that have made a contribution to the Global Warming conversation. These are the Intergovernmental Panel on Climate Change (IPCC), the UN Framework Convention on Climate Change (UNFCCC) together with it's better known amendment, the Kyoto Protocol, and the UK government commissioned Stern Report.
Back in 1990, environmentalists concerned about the observed
increase in green house gas (CO2, CH4) concentration (CO2 went from
0.028% circa 1900 to around 0.035% circa 1990) persuaded their
governments to form the IPCC. Governments submitted lists of interested
scientists, and from those lists panel members were selected by the
conveners. Since then the IPCC has brought out four reports at
approximately five year intervals.
SUMMARY AND CRITIQUE OF THE REPORTS.
The First Assessment Report of the IPCC (FAR1990) reported that environmental scientists on the committee agreed that there had been about a one degree Fahrenheit rise in mean surface temperature since 1900. This might have resulted from man's activities, or could be explained by natural variation. The FAR predicted that there would be a further one degree F rise over the next decade.
The Second Assessment Report of the IPCC (SAR, 1995) confirmed the findings of the FAR, and noted that GHG had increased, and that aerosols were countering the warming effect. It noted that the reliability of climate models had increased. The SAR was a controversial report. Leading scientist panel members claimed variously that "policy makers altered their final draft", and that there was "corruption of the peer review process" and that the summary had been altered to result in alarmist conclusions. The politically appointed convener of the summary stated that "none of the changes made was politically motivated".
The Third Assessment report of the IPCC (TAR2001) reported that there had been a 1.1 degree F rise in mean surface temperature since AD 1900. The models were getting better It was predicted that GHG concentrations would continue to rise, the mean surface temperature would continue to rise, (by a further ~3F to 8F by AD 2100) and the sea level would rise by between 10 and 90 centimeters by AD 2100. Again leading panel members claimed that the report was biased by ignoring or misrepresenting their results, and that damage estimates had been exaggerated by modifying economic variables.
The Fourth Assessment Report of the IPCC (IPCC4, 2007) determined that the level of the ocean would rise by about half a meter over the next 100 years. There was general agreement that the world has warmed by above half a degree centigrade in the last few decades. There was disagreement as to whether these changes are responsible for an increase of more than about 1% of hurricane activity. The consensus is that there is no persuasive evidence that weather patterns have substantially moved from the normal range. According to IPCC4, there is a 90% probability that 50% of (the one degree Fahrenheit of) global warming measured since the 1960's was caused by green house gases (GHG).
Most economists in the IPCC seem to assume that global warming has more costs than it has benefits. One of the obvious costs is that in a warmer world we would use an air conditioner more frequently, so would need more electricity and air conditioners. Other costs are more speculative, such as increased hurricane activity leading to damage to property. In temperate regions, (such as Dakotas, Canada, Northern Europe, Russia, Patagonia) global warming is expected to increase agricultural yields. In other places, such as Mediterranean Europe, Southern California, failing rainfall is expected to decrease yields. Another cost is expected to result from rising sea levels (less than one meter by 2100) either flooding lowlands (e.g. Bangladesh, Manhattan, Egyptian delta), or requiring construction of a dike system such as in Holland. So far as I am aware, the IPCC did not quantify the damage.
The KYOTO PROTOCOL
This was a 1997 amendment to UNFCCC 1992 which protocol came in to force on February 16th 2005. Two "Annex I" (industrially advanced) countries (Australia and USA) have not ratified the protocol. The protocol determines a "carbon quota" for the "Annex I" countries, and exacts a 30% penalty on countries that exceed their carbon quota. It now appears that some of the various countries that ratified the protocol acted precipitously. Some of the more enthusiastic countries (e.g. Canada's obligation was to reduce GHG by 6%, currently they have increased output by 27%, Spain was to reduce by 8%, currently increased by 49%) have exceeded their treaty obligations by a very wide margin. Since so many countries are failing to meet their quotas, it will be interesting to see how they avoid paying the penalties.
More recent activity on the global warming issue has been led by economists. The raison d'etre for economists is the optimization of "utility". Utility has a precise meaning in economics, which differs from the meaning in everyday English. It is an economist's word for the enjoyment and satisfaction that people experience from the things that they do, such as spending or saving money or camping out or whatever.
Economists have created a plethora of models for financial modeling of the economy, most of which have well known failings and strengths. As far back as 1992 economists like William Nordhaus of Yale were publishing in Nature that a carbon tax of $5/ton was the optimum utility price for carbon. He reasoned that the right to pollute is an untaxed benefit. There is no financial reason for a polluter to reduce pollution. Nordhaus had calculated that a tax was an appropriate way for society to persuade polluters to reduce their pollution. Taxes are the optimum method for controlling the production of price sensitive goods. On the other hand, economists have found that permits are the optimum method for controlling price insensitive goods.
Expanding on this insight, the UK government commissioned public servant Nicholas Stern to produce a "White Paper" on the economic cost of climate change. This white paper became known as the Stern Report. Stern was originally an academic who recently (1999) turned his hand to the bureaucratic plowshare. Like all government "white papers" the Stern Report was not peer reviewed, and has met a lot of criticism from academics on that basis.
- Stern has introduced little new science or economics in the review.
- The review is considered unsound by many leading scientists because peers were not consulted and procedures were not transparent in the selection of appropriate environment and economic models and in the selection of values for applicable variables.
- Leading scientists (e.g. Noordhaus) are critical that Stern appears to have utilized models and selected variables that have resulted in a "worst case scenario".
- KYOTO introduced the world to the necessity of reducing GHG for the sake of environmental protection, in the hope of reducing serious but nonspecific damage. Stern has brought the Kyoto public closer to modern economist's thinking by application of the concept that an economic analysis of the effects and consequent costs of global warming should be used to determine our response.
Environmental economists agree that while Stern's numbers might be extreme, the very important issue publicized by The Stern Review is that we do not want the cost of reducing environmental damage to exceed the cost which would be incurred as a result of that environmental damage.