Rules needed as it’s ‘too early’ to say sun-dimming tech is helpful

With a miniature experiment to try to cool the planet by blocking sunlight planned in Arizona, US, international rules to govern “geoengineering” efforts must be put in place quickly, a governance advocate said.

In the 2015 Paris deal on climate change, world leaders agreed to work towards keeping the average global temperature to “well below” two degrees Celsius.

An Adelie penguin stands atop a block of melting ice in East Antarctica.

However, with the shift away from fossil fuels happening slower than needed, and the world on track to warming more than three degrees Celsius, some scientists now say engineering efforts to lower the risks of excess warming may be needed.

Those might range from efforts to dump iron into the ocean to help carbon-absorbing plankton grow more quickly to spraying saltwater into sea clouds to make them reflect more sunlight.

Phytoplankton blooms seen in an ocean eddy, which can trap carbon and sink it to the bottom of the ocean with the help of iron fertilization, but the geoengineering technique remains controversial.

Researchers at Harvard University hope to use a high-altitude balloon this year to release about a kilogram of sun-dimming mineral dust into the stratosphere above the US state of Arizona.

The experiment would mimic, on a tiny scale, how large volcanic eruptions cool the earth by blasting ash into the atmosphere.

However, the technique does not actually remove carbon dioxide from the atmosphere, and so would have little effect on climate change concerns, such as increasing acidification of the world’s oceans.

An open, inclusive discussion on how the world will research and govern solar geoengineering is “urgently” needed in the face of such plans, said Janos Pasztor, head of the Carnegie Climate Geoengineering Governance Initiative.

“We could be in danger of events overtaking society’s capacity to respond prudently and effectively,” he said on Friday before a speech at Arizona State University.

In a leaked draft of a report about global warming due out in October, a UN panel of climate experts said such solar geoengineering, at larger scale, may be “economically, socially and institutionally infeasible.”

Scholars from a range of climate-vulnerable countries noted in the Nature journal last week that “the technique is controversial, and rightly so. It is too early to know what its effects would be: it could be very helpful or very harmful.”

Simon Nicholson, co-executive director of the Forum for Climate Engineering Assessment, based in Washington, US, said while early geoengineering experiments like Harvard’s present no physical risk, they could lay the groundwork for eventual large-scale deployment of the technology.

“The urgency comes from the desire to get out in front of something that might be important a few years from now,” Nicholson said.

“The risk comes from the slippery slope argument, that it could quickly move from something that looks like a test to something that looks like deployment.”

Large-scale use of such sun-dimming technology could have a range of little-understood side effects, scientists warn, including potentially shifting Asian monsoons that are crucial to farming processes that feed billions.

Nicholson said the planned Arizona experiment has met all the legal requirements, and the researchers have pushed to include an environmental impact assessment even though it is not formally required by law.

“They could do this experiment tomorrow. Under Harvard research guidelines and US law there is nothing stopping them. All the boxes are checked,” he said.

But “they’re going slow because they realize that, as the first labeled solar geoengineering experiment, they have an obligation to get it right,” he said.

Pasztor, a former UN assistant secretary-general on climate change, said a growing number of governments “recognize some parts of geoengineering are coming, and we need to seriously deal with it.”

“It’s on their radar screen,” he said.

(CGTN)