Lowering Local weather Change Dangers With the Proper Dose of Geoengineering

Geoengineering Climate Change Risks

Stratospheric aerosol geoengineering is the concept including a layer of aerosol particles to the higher environment can scale back local weather adjustments attributable to greenhouse gases reminiscent of carbon dioxide.

Earlier analysis exhibits that photo voltaic geoengineering could possibly be achieved utilizing commercially out there plane applied sciences to ship the particles at a value of some billion dollars per 12 months and would scale back world common temperatures. Nonetheless, the query stays whether or not this strategy may scale back essential local weather hazards at a regional degree. That’s, may it scale back region-by-region adjustments in water availability or excessive temperatures?

Outcomes from a brand new research by UCL and Harvard researchers counsel that even a crude methodology like injecting sulfur dioxide within the stratosphere may scale back many essential local weather hazards with out making any area clearly worse off.

The findings, printed right this moment in Environmental Analysis Letters, used outcomes from a classy simulation of stratospheric aerosol geoengineering to guage whether or not the strategy may offset or worsen the results of local weather change world wide. How these results differed below totally different temperature eventualities was additionally examined.

The group discovered that halving warming by including aerosols to the stratosphere may average essential local weather hazards in virtually all areas. They noticed an exacerbation of the results of local weather change in solely a really small fraction of land areas.

Lead writer, Professor Peter Irvine (UCL Earth Sciences), mentioned: “Most research deal with a situation the place photo voltaic geoengineering offsets all future warming. Whereas this reduces total local weather change considerably, we present that in these simulations, it goes too far in some respects resulting in about 9% of the land space experiencing larger local weather change, i.e. seeing the results of local weather change exacerbated.

“However, if instead only half the warming is offset, then we find that stratospheric aerosol geoengineering could still reduce climate change overall but would only exacerbate change over 1.3% of the land area.”

The group emphasise that photo voltaic geoengineering solely treats the signs of local weather change and never the underlying trigger, which is the build-up of CO2 and different greenhouse gases within the environment. It ought to subsequently be thought of as a complementary strategy to emissions cuts as a technique to deal with local weather change.

The research is a follow-up to a paper printed final 12 months in Nature Local weather Change* confirmed related outcomes when photo voltaic geoengineering was approximated by merely turning down the solar. That prior research begged the query: would the outcomes maintain up with a extra reasonable simulation utilizing injection of sulfur dioxide, the best recognized methodology of photo voltaic geoengineering.

“Our results suggest that when used at the right dose and alongside reductions in greenhouse gas emissions, stratospheric aerosol geoengineering could be useful for managing the impacts of climate change. However, there are still many uncertainties about the potential effects of stratospheric aerosol geoengineering and more research is needed to know if this idea is truly viable,” added Dr. Irvine.

The group used information from the Geoengineering Giant Ensemble Research, which used a classy climate-chemistry mannequin to simulate the local weather response to a hypothetical deployment of stratospheric aerosol geoengineering. On this mannequin research, sulfur dioxide was launched at totally different latitudes within the Tropics to provide a layer of aerosols tuned to maintain temperatures regular below an excessive world warming situation.

The researchers centered on adjustments in imply and excessive temperature, adjustments in water availability and adjustments in excessive precipitation, i.e. local weather variables that decide key local weather dangers.

Earlier work recommended that stratospheric aerosol geoengineering may result in a considerable weakening of monsoons and an intensification of drought. Nonetheless, the authors discovered that in these areas the place halving warming with stratospheric aerosol geoengineering exacerbated change, it elevated water availability relatively than decreased it. This implies that issues that stratospheric aerosol geoengineering may result in aridification and drought could possibly be misplaced.

Co-author, Professor David Keith (Harvard’s Engineering and Utilized Sciences and Kennedy faculty), mentioned: “Early research with climate models consistently shows that spatially uniform solar radiation modification could significantly reduce climate risks when combined with emissions cuts. But, should we trust the models? Uncertainties are deep and no single result is trustworthy, but this paper is a step towards more realistic modeling from injection to regional impacts.”

The group at the moment are researching the projected results of stratospheric aerosol geoengineering on the water cycle in additional depth to attempt to perceive the potential advantages and dangers to society and ecosystems.

References:

19 March 2020, Environmental Analysis Letters.
DOI: 10.1088/1748-9326/ab76de

“Halving warming with idealized solar geoengineering moderates key climate hazards” by Peter Irvine, Kerry Emanuel, Jie He, Larry W. Horowitz, Gabriel Vecchi & David Keith, 11 March 2019, Nature Local weather Change.
DOI: 10.1038/s41558-019-0398-8

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