Harvard set for geoengineering test
US scientists are testing possible solar geoengineering techniques.
A new research programme will see aerosols injected into the stratosphere, 20km above Earth, to find out how to safely simulate the atmospheric cooling effects of a volcanic eruption.
The experts say a technological fix for global warming may one day be needed if current measures fail.
The first substances to be trialled are designed to disperse water and calcium carbonate particles.
“This is not the first or the only university study,” said Gernot Wagner, the Harvard University project’s co-founder, “but it is most certainly the largest, and the most comprehensive.”
Janos Pasztor, former assistant climate chief at the UN and now leader of the Carnegie Climate Geoengineering Governance Project, says the tests will be on a small scale and strictly controlled.
Mr Pasztor says; “The real issue here is ... What does moving experimentation from the lab into the atmosphere mean for the overall path towards eventual deployment?”
He said most scientific observers believe opportunities to limit the warming world to a 1.5°C rise are “practically gone”, especially given that atmospheric carbon dioxide concentrations would continue rising for decades after the planet reached any ‘net zero emissions’ point.
Geoengineering advocates say any cloud-seeding or other approaches would be used to compliment – not substitute – aggressive emissions reductions action.
“It is appropriate that we spend money on solar geoengineering research,” says Kevin Anderson from the Tyndall Centre for Climate Change Research.
“But we also have to aim for 2°C with climate mitigation and act as though geoengineering doesn’t work, because it probably won’t.”
The Harvard team’s promotional video for the project says using just one per cent of current climate mitigation funds on geoengineering would allow the planet to be covered with a solar shield for around $10 billion a year.
But this idea is alarming for established climate scientists, who fear funding could be drained from proven mitigation technologies (like wind and solar energy) to new ideas that carry more potential for significant damage and disaster.
Frank Keutsch, an atmospheric sciences professor leading the Harvard experiment, says solar geoengineering is “a terrifying prospect”, but “at the same time, we should never choose ignorance over knowledge in a situation like this.”
“If you put heat into the stratosphere, it may change how much water gets transported from the troposphere to the stratosphere, and the question is how much are you [creating] a domino effect with all kinds of consequences? What we can do to quantify this is to start with lab studies and try to understand the relevant properties of these aerosols.”
The Stratospheric controlled perturbation experiments (SCoPEX) will see water molecules sprayed into the stratosphere to form a 1km long and 100m wide icy plume.
That plume will then be monitored by a manoeuvrable flight balloon.
There are plans for the experiment to be replicated with a limestone compound, but the researchers stress this will neither absorb solar or terrestrial radiation, nor deplete the ozone layer.
The project is backed by Bill Gates and other philanthropic leaders, and reports say the aerospace industry will be keeping a close eye as well.
The shift of geoengineering from fearful fantasy to research reality will be highlighted at the upcoming Gordon research conference in July, featuring figures from the National Oceanic and Atmospheric Administration (NOAA) and Oxford University.