Geo-engineering wins scant enthusiasm at climate talks
Dec 02 2012 , Doha
Many scientists say the proposed solutions, known as geo-engineering, are little understood and might have side effects more damaging than global warming, which is projected to cause more floods, heatwaves, droughts and rising sea levels.
“Let’s first use what we know,” said Christiana Figueres, head of the UN climate change secretariat, dismissing suggestions that it was time to try geo-engineering to halt a rise in greenhouse gas emissions.
“There are so many proven technologies we know exist that are tried and true that have not been used to their maximum potential,” she told Reuters. “To begin with, the simplest is energy efficiency.”
Geo-engineering options include adding sun-reflecting chemicals to the upper atmosphere to mimic the effect of big volcanic eruptions that mask the sun, or fertilising the oceans to promote the growth of algae that soak up carbon from the air.
Among other ideas, a giant mirror could be placed in space to block some sunlight or sea spray could be injected into the air to create clouds whose white tops would reflect sunlight.
“Let’s face it, geo-engineering has a lot of unknowns,” Rajendra Pachauri, chairman of the UN’s panel of climate scientists, told Reuters on the sidelines of UN-led climate change talks among 200 nations in Doha from November 26-Dec 7.
“How can you go into an area where you don’t know anything?” he said. The Intergovernmental Panel on Climate Change (IPCC) is examining geo-engineering in depth for the first time as part of a major report due in 2013 and 2014.
Still, one study by US scientists in August indicated that planes or airships could carry a million tonnes a year of sun-dimming sulphate materials high into the atmosphere for an affordable price tag of below $5 billion.
That would be far cheaper than policies to cut world greenhouse gas emissions, estimated to cost between $200 billion and $2 trillion a year by 2030, they wrote in the journal Environmental Research Letters.
“If you are looking at solutions you could look at solar energy,” said Mira Mehrishi, head of India’s delegation in Doha. “It’s a little premature to start looking at geo-engineering.”
“There’s a lot of skepticism” about geo-engineering, said Artur Runge-Metzger of the European Commission. “Research is necessary to see if it could be viable in one way or other.”
UN negotiations on slowing global warming have been running since a UN climate convention was agreed in 1992.
One problem is that adding sulphates - a form of pollution - to the air would not slow an acidification of the oceans since concentrations of greenhouse gases led by carbon dioxide in the atmosphere would keep building up.
Some carbon dioxide, absorbed into the oceans, reacts to form carbonic acid. That erodes the ability of creatures from clams or mussels to lobsters and crabs to build their protective shells. In turn, that could disrupt marine food chains.