US considers risky geo-engineering options to avert abrupt climate change

The US government wants the world's scientists to develop technologies to block sunlight as a last-ditch way to halt 'Abrupt Climate Change' (ACC), in case it were to occur. It says research into 'geo-engineering' techniques such as seeding the oceans with iron, pumping sulphate droplets into the atmosphere, or launching giant mirrors into space would be an "important insurance" against rising emissions, and has lobbied for such a strategy to be recommended by a major UN report on climate change, the first part of which will be published on Friday.

The US has also attempted to steer the UN report, prepared by the Intergovernmental Panel on Climate Change (IPCC), away from conclusions that would support a new worldwide climate treaty based on binding targets to reduce emissions - as sought by Europe. It has demanded a draft of the report be changed to emphasise the benefits of voluntary agreements and to include criticisms of the Kyoto Protocol, the existing treaty which the US administration opposes. The final IPCC report, written by experts from across the world, will underpin international negotiations to devise a new emissions treaty to succeed Kyoto, the first phase of which expires in 2012. World governments were given a draft of the report last year and invited to comment.

Risky techniques
The US response, technically entitled "U.S. Government Review of the Second Order Draft of WGIII Contribution 'Climate Change 2007: Mitigation of Climate Change'" [*.pdf], says the idea of interfering with sunlight should be included in the summary for policymakers, the prominent chapter at the front of each IPCC report. It says: "Modifying solar radiance may be an important strategy if mitigation of emissions fails. Doing the R&D to estimate the consequences of applying such a strategy is important insurance that should be taken out. This is a very important possibility that should be considered."

Scientists have previously estimated that reflecting less than 1% of sunlight back into space could compensate for the warming generated by all greenhouse gases emitted since the industrial revolution. Possible 'geo-engineering' techniques include putting a giant screen into orbit, thousands of tiny, shiny balloons, or microscopic sulphate droplets pumped into the high atmosphere to mimic the cooling effects of a volcanic eruption. The IPCC draft said such ideas were "speculative, uncosted and with potential unknown side-effects".

A much safer option: Bio-Energy with Carbon Storage
The proposed geo-engineering options are risky and unnecessary because there exists a method that is safe and delivers energy while being implemented. The system is known as 'Bioenergy with Carbon Storage' (BECS) and is easy to understand: biomass would be planted on a massive scale at strategic locations around the planet and take CO2 out of the atmosphere. This biomass would then replace all coal, natural gas and oil in power stations that are connected to carbon sequestration facilities. In such a radical carbon negative energy system, atmospheric carbon would be put back into the ground -- where it used to be before the world started using fossil fuels. Societies would be able to function normally while BECS is being implemented on a large scale.

According to scientists, BECS can take us back to pre-industrial carbon levels in a short time (earlier post):

Under strong assumptions appropriate to imminent ACC, pre-industrial CO-levels can be restored by mid-century using BECS [...].
Negative emissions energy systems are key to responding to ACC because – taking account of rising levels on non-CO2 greenhouse gases, for which no means exists for accelerating natural removal processes – the need may be to get to CO2 levels below pre-industrial. This cannot be done by natural absorption, even with zero emissions
energy [such as wind, solar, nuclear].
A portfolio of Bio-Energy with Carbon Storage technologies, yielding negative emissions energy, may be seen as benign, low risk, geo-engineering that is the key to being prepared for ACC.

However, the US submission does not take the option into account:
biomass :: bioenergy :: biofuels :: energy :: sustainability :: abrupt climate change :: greenhouse gas emissions :: carbon dioxide :: CO2 :: geo-engineering :: BECS :: Kyoto :: IPCC :: United Nations :: US ::

What's more, it complains the IPCC draft report is "Kyoto-centric" and it wants to include the work of economists who have reported "the degree to which the Kyoto framework is found wanting". It takes issue with a statement that "one weakness of the [Kyoto] protocol, however, is its non-ratificiation by some significant greenhouse gas emitters" and asks: "Is this the only weakness worth mentioning? Are there others?"

It also insists the wording on the ineffectiveness of voluntary agreements be altered to include "a number of them have had significant impacts" and complains that overall "the report tends to overstate or focus on the negative effects of climate change." It also wants more emphasis on responsibilities of the developing world.

The IPCC report is made up of three sections. The first, on the science of climate change, will be launched on Friday. Sections on the impact and mitigation of climate change - in which the US wants to include references to the sun-blocking technology - will follow later this year.

The likely contents of the report have been an open secret since the Bush administration posted its draft copy on the internet in April. Next week's science report will say there is a 90% chance that human activity is warming the planet, and that global average temperatures will rise another 1.5C to 5.8C this century depending on emissions. The US response shows it accepts these statements, but it disagrees with a more tentative conclusion that rising temperatures have made hurricanes more powerful.

More information:
US Government Review Collation: "U.S. Government Review of the Second Order Draft of WGIII Contribution 'Climate Change 2007: Mitigation of Climate Change'" [*.pdf] - Sept. 14, 2006

The Guardian: US answer to global warming: smoke and giant space mirrors - Jan. 27, 2007

RealClimate, Climate Science from Climate Scientists: Geo-engineering in vogue... - Jun. 28, 2006

Center for Research on Globalization: Climate Change and Geoengineering - ‘intentional large scale manipulation of the global environment’ - October 20, 2005