Scientists are proposing an unproven way to tackle climate change by spraying sun-dimming chemicals into the Earth’s atmosphere.
A technique known as stratospheric aerosol injection (SAI) could cut the rate of global warming in half, they say.
The research was led by scientists at Harvard and Yale universities and published in the journal Environmental Research Letters.
The idea would involve spraying large amounts of sulphate particles into the Earth’s lower stratosphere at altitudes as high as 12 miles.
The scientists say they will deliver the sulphates with specially designed high-altitude aircraft, balloons or large naval-style guns.
The report does, however, acknowledge that the technique is purely hypothetical right now.
There is no existing technology or aircraft suitable for adaptation but the team say the system could be created in 15 years time.
They say they are ‘developing a new, purpose-built tanker with ‘substantial payload capabilities’ and would neither be ‘technologically difficult nor prohibitively expensive.’
The cost of launching the SAI system is estimated at £2.7 billion ($3.5 bn) with running costs of £1.7 billion ($2.25 bn) a year.
‘We make no judgment about the desirability of SAI,’ the report states.
‘We simply show that a hypothetical deployment program commencing 15 years hence, while both highly uncertain and ambitious, would indeed be technically possible from an engineering perspective. It would also be remarkably inexpensive.’
The team acknowledge that there would be extreme risks with the hypothetical system.
Coordination between multiple countries in both hemispheres would be required.
Aside from that they say the SAI techniques could jeopardise agriculture, lead to droughts or cause extreme weather.
Dr Gergot Wagner from Harvard University’s School of Engineering and co-author of the study said: ‘Given the potential benefits of halving average projected increases in radiative forcing from a particular date onward, these numbers invoke the ”incredible economics” of solar geoengineering.
‘Dozens of countries could fund such a program, and the required technology is not particularly exotic.’
WHAT SHOULD THE EU BE DOING TO PROTECT PEOPLE FROM CLIMATE CHANGE?
In 2013, the European Academies’ Science Advisory Council (EASAC) published a report which looked at the frequency of extreme weather events.
Since then, there has been a continued rise in how common these events occur.
In order to cope when such adverse weather conditions strike, they made recommendations as to how the EU can better protect its citizens from climate change.
The report claimed that in order to best deal with the issues, it is necessary to understand them first.
To understand how global warming will affect the extremes of weather, it is necessary to study and model them.
2. Heat waves
Across the European continent, heatwaves can vary massively and have vastly different impacts.
Understanding the nuances of these phenomena is key to weathering the storm.
3. Flood defence and early warning
Good practice in flood preparedness and for flood defence across Europe should be shared, including information about different responses to flood preparedness and flood warnings.
The report stated that the agriculture sector as a whole needed to improve.
Vulnerability to extreme weather and possible measures to increase resilience should be produced.
5. Strengthen the knowledge of climate change
The research found that it was crucial that we viewed climate change adaptation as a continuous process.
In order to do this sustained observations, analysis and climate modelling about the Earth are integral parts of a robust and flexible climate-change adaptation strategy.
It claims knowledge dissemination, innovation and building international relationships is key.
6. Changes in policies
Before adaptation can be achieved, there are several barriers which include those that are physical, technical, psychological, financial, institutional and knowledge-based.
The proposals also don’t address the issue of rising greenhouse gas emissions, which are a leading cause of global warming.
But not everyone is convinced.
Philippe Thalmann from the École Polytechnique Fédérale de Lausanne, an expert in the economics of climate change said the system would be more costly and ‘much more risky over the long run’.
David Archer from the department of geophysical science at the University of Chicago told CNN: ‘The problem with engineering climate in this way is that it’s only a temporary Band-Aid covering a problem that will persist essentially forever.
‘It will be tempting to continue to procrastinate on cleaning up our energy system, but we’d be leaving the planet on a form of life-support.
‘If a future generation failed to pay their climate bill they would get all of our warming all at once.’