

Geoengineering has been a hot topic over the past little while and into this mix has come a new study looking at the possibility of using solar geoengineering to counter the loss of Arctic sea ice by tailoring geoengineering by region and by need.

A team of leading researchers developed a new computer model that promises to maximise the effectiveness of solar radiation management by mitigating its potential side effects and risks.

The model was highlighted in a study published in the November issue of the journal Nature Climate Change.

Solar geoengineering is easy to outline and harder to be specific about: in short, seed the atmosphere with particles that reflect light back into space and we can mitigate how much is reaching planetside.







However most solar geoengineering plans have involved a uniform spread. Such a dramatic intervention in the planet’s climate system would have untold consequences over the whole planet. Simply put, minimising solar radiation in one part of the planet may not have the same effect on the other side of the world, or even next door.

“Our research goes a step beyond the one-size-fits-all approach to explore how careful tailoring of solar geoengineering can reduce possible inequalities and risks,” says co-author David Keith (pictured at right), Gordon McKay Professor of Applied Physics at the Harvard School of Engineering and Applied Sciences (SEAS) and Professor of Public Policy at Harvard Kennedy School. “Instead, we can be thoughtful about various tradeoffs to achieve more selective results, such as the trade-off between minimizing global climate changes and minimizing residual changes at the worst-off location.”

“There has been a lot of loose talk about region-specific climate modification. By contrast, our research uses a more systematic approach to understand how geoengineering might be used to limit a specific impact. We found that tailored solar geoengineering might limit Arctic sea ice loss with several times less total solar shading than would be needed in a uniform case.”

The researchers believe that varying the amount of sunlight deflected away from the Earth by region and by season could combat some of the issues with uniformly mitigating sunlight.

“These results indicate that varying geoengineering efforts by region and over different periods of time could potentially improve the effectiveness of solar geoengineering and reduce climate impacts in at-risk areas,” says co-author Ken Caldeira, Senior Scientist in the Department of Global Ecology at the Carnegie Institution for Science.

Unsurprisingly the researchers are quick to make clear that even though they are using a state of the art computer model, the reality may be something entirely different. There would be a variety of uncertainties that may crop up in the event of such a selective seeding of the planet’s atmosphere, the any interference with Earth’s climate system may provoke intentional or unintentional responses.

“While more work needs to be done, we have a strong model that indicates that solar geoengineering might be used in a far more nuanced manner than the uniform one-size-fits-all implementation that is often assumed. One might say that one need not think of it as a single global thermostat. This gives us hope that if we ever do need to implement engineered solutions to combat global warming, that we would do so with a bit more confidence and a great ability to test it and control it.”

Source: Harvard School of Engineering and Applied Sciences

Image Source: NASA Goddard Photo and Video