Shooting giant mirrors into orbit and scattering carbon-absorbing rocks across the earth may be needed in a “Plan B” to fight global warming, the U.K.’s national science academy said.
The experimental techniques must be developed for use as an “emergency” remedy to ensure a safe future for the Earth, the Royal Society said today in a report. They’re needed in case measures to reduce greenhouse gases such as carbon dioxide are unsuccessful in containing rising temperatures, it said.
Governments should invest about 100 million pounds ($160 million) a year to research the geo-engineering techniques, John Shepherd, a professor of Earth systems science at Southampton University, told reporters today in London. Methods that suck CO2 from the air are preferable to projects that block sunlight from the Earth with mirrors or reflective particles, he said.
“If Plan B is to be an option in the future, considerable research and development of the different methods, their environmental impacts and governance issues must be taken now,” Shepherd said. He led the research produced by the Royal Society, which counts 73 Nobel prize winners among its members.
In three months governments from 192 nations are due to meet in Copenhagen to write a treaty to fight global warming by bringing down greenhouse-gas emissions. Shepherd said “there clearly is a risk” talks will fail to produce an accord that delivers emissions reductions of the scale and pace required.
Blocking The Sun
The environmental group Greenpeace said politicians are unlikely to reach agreement on geo-engineering.
“Intervening in our planet’s systems carries huge risks, with winners and losers,” Greenpeace’s chief scientist, Doug Parr, said today in an e-mailed statement. “If we can’t deliver political action on clean energy and efficiency then consensus on geo-engineering is a fantasy.”
The researchers, based in the U.S., the U.K. and Canada, examined two broad groups of geo-engineering methods, which they termed carbon-dioxide removal and solar-radiation management.
Planting trees, creating algal blooms in the oceans, building air “scrubbers” that absorb CO2 and using rocks that react with the air to remove carbon would help reduce levels of greenhouse gases, they said. Sun-blocking measures included painting roofs white to reflect solar radiation.
Carbon-dioxide removal techniques take longer to become effective are more expensive in keeping temperatures down, they said. Even so, because sun-blockers don’t tackle other effects of carbon emissions, such as their ability to acidify oceans, they shouldn’t be considered an alternative to emissions reductions and CO2 removal, the researchers wrote.
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Alex Morales, Bloomberg, 1 September 2009. Full article.
