Solar geoengineering is like pulling the goalie in a hockey game

During the financial crisis of 2008, I first heard about the possibility of solar geoengineering, or planes spraying sulphate particles high in the atmosphere to reflect sunlight back to space. I had invited Gwynne Dyer, an author and historian, to speak in Truro, N.S. He stunned many of us by saying politicians would probably not make the tough decisions necessary to address climate change and would delay until solar geoengineering was the only option left.

When I contemplate too long what we might have done from 2008 until now to reduce greenhouse gas emissions (GHGs), contrasted with the paucity of political action in that time, I have to slap my forehead and utter, “Ugh.” It’s like a highly rated hockey team frittering away their final series until they are down a goal in the last minute of the last period in the last game and then pulling their goalie to gain more offence. The desperate effort could backfire and seal their demise.

Carbon dioxide (CO₂) levels were 385 parts per million (ppm) in 2008 but are now beyond 415 ppm, too far north of the 350 ppm needed to restore climate stability. We’re nearing the end of the third period.

Policies are urgently needed to reduce GHGs by at least seven per cent each year from now to 2030 and beyond. In 2020, it appeared that a seven per cent reduction could be attributed to COVID-19. Now that we know it is possible, we need global, national, provincial and municipal political will to decrease GHGs another seven per cent in 2021 and another seven per cent in 2022, and so on.

Regardless of lower emissions in 2020, it was the hottest year on record, along with 2016. Think of GHGs going into an almost full bathtub. If the inflow (GHG emissions) declines by seven per cent, there are still too many GHGs in the bathtub that is too slowly draining (e.g., sequestration of carbon by trees and forage crops). That is why more incentives, such as payments for increasing soil organic carbon as proposed by the 4 per 1000 Initiative, are needed for farmers and foresters to sequester more carbon and for industries and citizens to emit fewer GHGs every year.

Our habit of pouring CO₂ into the atmosphere means that oceans will absorb some of that CO₂ and keep acidifying. Reflecting light back into space from sulfur dioxide would still allow CO₂ buildup and thus put marine life under stress. Sulfur dioxide also might delay ozone regeneration in the stratosphere.

According to an article in the Guardian, “Blocking the sun could come with a host of other issues, from negative impacts on crop productivity and shifts in rainfall.” Furthermore, having started solar geoengineering, we may be committed because to stop would be to allow too much solar radiation through too abruptly.

“Sulphate particles ... would not stay aloft for more than a couple of years. Planes would have to keep flying and spraying ever-larger quantities essentially forever,” according to Yale Environment 360. Meanwhile, “the suppression of solar radiation could well create massive changes in weather systems and rainfall patterns, which are mostly driven by solar energy. The Asian monsoon, on which two billion people depend for their food crops, might shut down.”

How will soil, crops, forests and water bodies respond to continuously descending sulphate?

There are serious scientific investigations into the possibilities and potential risks of solar geoengineering at institutions such as Cambridge, Oxford, Harvard, the Institute for Applied Systems Analysis and the National Academy of Sciences, as well as others in China.

Will this research tempt politicians to dither about reducing GHGs even more than they already are? Who should decide, and on what authority, if and when to start solar geoengineering with given specifications?

Recent research is suggesting solar geoengineering may not have substantial negative consequences. “It is therefore crucial to ask of any specific scenario of solar geoengineering deployment: What would have occurred if more, or less, cooling had been applied?” This paper suggests some of the negative effects on rainfall in local regions could be mitigated with lower levels of solar geoengineering than originally proposed.

We only have one planet. Models, while helpful, are inexact. Do we want to risk this one planet with a potentially dangerous global intervention based on models? A well-known philosopher, Yogi Berra, said: “In theory, there is no difference between theory and practice.”

In practice, our planet experiences increasing intensities of hurricanes, floods, droughts and fires. We also still have the practical option to reduce GHGs every year.

Let’s get on with it, before the end of the third period.

Ralph Martin has a PhD in plant science and is the founder of the Organic Agriculture Centre of Canada. He also previously served as professor and Loblaw Chair in Sustainable Food Production at the University of Guelph.