Nicholas Stern may have underestimated the cost of cutting carbon, whilst the latest OECD climate report fudged the science to cut costs. Zara Maung and Chris Bianchi investigate the real economics of climate change.

Over the past two years, an increasing number of macro-economic reports and one major scientific report have been commissioned by governments to advise them on climate change policies.
The effect of these reports has been overwhelming. As a result, global warming has been established as one of the greatest threats to humankind this century.
The major scientific report predicted the effects of rising levels of CO2. It was compiled by the International Panel on Climate Change (IPCC) in 2007, the intergovernmental science body that subsequently shared the Nobel Peace Prize with Al Gore.
The trend for macro-economic reports on climate change began in 2006, when the UK economist Sir Nicholas Stern released his groundbreaking economic review estimating the costs of mitigating climate change.
In March 2008, four months after the release of the science report by the IPCC, the Organisation for Economic Co-operation and Development (OECD) released an economic report that, on the surface, seemed broadly to agree with Stern’s.
Credibility gap
Both the Stern and OECD reports play an important role in advising developed countries (in Stern’s case, the UK) on what they could do to lower their CO2 emissions to sustainable levels. Both claim to prescribe policies which would “avoid global warming’s harshest effects”.
However, it appears that although the CO2 stabilisation levels recommended by the Stern report mirror those indicated by the IPCC, the recommendations by the OECD are more generous with CO2 levels.
A growing voice of dissent amongst economists says that Stern’s original report may have underestimated government spending required to tackle climate change. Significant confusion has also arisen over the costs and imperative of mitigation efforts compared with the costs of adapting to the effects of climate change, a hidden expense which receives little mention in the Stern report.
Economists’ dismay at the rising cost of stopping global warming, combined with the pitiful record of under spending by governments so far, may be triggering a worrying economic policy shift away from IPCC targets towards ones that seem more economically achievable.
Confusion in the atmosphere
There are a number of conflicting climate science theories around, predicting different effects from rising CO2 levels, as well as differing economic theories on how governments should deal with rising CO2 emissions from industry.
Governments, however, need one accepted scientific viewpoint, not a barrage of conflicting ideas, in order to react. The IPCC and the macro-economic reports try to provide this, by aggregating the ideas and finding a “middle way” on the science and the economics of climate change.
Overall, the reports all agree that rising CO2 levels will lead to global temperatures warming and increasing damage to the environment and the economy.
Degrees of difference
The 2007 IPCC report, originally set up by the World Meteorological Organisation and the United Nations Environment Programme, concurred with Nicholas Stern’s target for stabilising CO2 levels – an upper limit of 550 CO2 parts per million – within 20 years. This would, according to the IPCC, probably involve a global temperature rise of around 2C (global average annual temperature change relative to 1980-1999).
According to the IPCC assessment, a 3C rise would bring about widespread damage to agriculture, a shift in disease vectors and infrastructural damage from floods and storms. The main OECD policy package resulting from the OECD report, however, settles for a far higher rise in CO2 than Stern. It relies on spending 1% of projected growth in global GDP until 2030 to reduce the annual increase in greenhouse emissions from the current 37% to 13% by 2030.
A question of editing
Jan Corfee-Morlot, a senior OECD researcher who was involved in writing both the OECD and IPCC reports, is aware of the disparities between the economics and the climate science. She explains to ClimateChangeCorp that some of the economic recommendations in the OECD report that did correspond with the IPCC report were edited out of the OECD’s main policy recommendations to governments.
Corfee-Morlot says that in the earlier chapters of the OECD report the economic calculations were more ambitious: “We summarised the results of a fuller range of climate change policies… consistent with the lowest of the scenarios in the IPCC assessment, where emissions peak in about 2015.” The more ambitious recommendations suggested implementing an escalating global carbon tax.
Corfee-Morlot says that whilst the main policy package recommended by the OECD “includes a realistic set of mitigation policies for greenhouse gases”, she concedes it is “less ambitious than others analysed in the report”.
-- this post is updated in 2008-5-5 14:23:51. |