April 5, 2024


Is Solar Radiation Modification (SRM) a good approach to combat global warming?

According to several estimates, 2023 was the warmest year on record. It wasn’t even close. The annual average temperature was 1.45 degrees Celsius above pre-industrial levels. Every month between June and December had new monthly records. July and August were the hottest on record. The alarm bells have been ringing for quite some time, and countries are looking to mitigate the effects.

Many approaches have been adopted. Most of them are conventional like reducing greenhouse emissions, switching to renewable energy, etc. However, some unconventional ones have also been discussed. One of them is called Solar Radiation Modification (SRM). It involves cooling the Earth rapidly by reflecting a portion of sunlight back into space. It might sound absurd and science fiction-y. However, some see it as a viable method. Would it be?


SRM, or solar geoengineering as it’s sometimes known, has been gaining traction among some countries and climate scientists as a viable method to help tackle global warming. It’s obviously all hands on deck in combating this, and any possible solution is being looked at.

The Intergovernmental Panel on Climate Change (IPCC) has made it clear that the world will most likely exceed, for several decades, the 1.5-degree Celsius goal. Climate scientists are anxious about how that will play out. We know for sure it’s not going to be anything good.

It’s a problem where we know the cause and its effects. Currently accepted tools and strategies have been deployed across the world, some would say, to relatively mixed results. Some argue there’s no guarantee that current strategies will be sufficient to keep temperature increase below 1.5 degrees Celsius.

SRM is actually an umbrella term that consists of various approaches. Among them are Cirrus Cloud Thinning (CCT), Marine Cloud Brightening (MCB), and Stratospheric Aerosol Injection (SAI). SRM, in particular, has to do with the sun’s rays.

It’s an idea that the Biden administration has reportedly been open to exploring. Last year, a White House report stated that more research is needed into SRM. In particular, figuring out how to deflect the sun’s rays and what the side effects could be for the planet. However, the White House wasn’t going to change its climate change strategy and said there were no plans to set up any comprehensive research program for SRM.

It’s the attitude many have about this approach – curiosity with a hefty dose of scepticism. But that hasn’t stopped startups from funding research since they see some promise. The Alliance for Just Deliberation on Solar Geoengineering is looking to bring developing countries to the table to discuss SRM. The group’s emergence is a sign of how this approach is increasingly seen as a viable option.

At this point in time, a few things are clear. This technique has clearly caught the attention of scientists and policymakers. Some see merits in using SRM. Others aren’t convinced.

VIEW: Could give it a shot

Broadly speaking, those who favour this technique believe the benefits outweigh any potential consequences. We already have one side of the equation well understood by fixing the issue at the source by replacing fossil fuels with renewable energy sources that don’t produce greenhouse gases. SRM looks at the other side of that equation. Reflecting enough extra sunlight will be a herculean effort, but it could be cheaper compared to the trillions of dollars spent on decarbonising the world.

If SRM is adopted, it could help reduce the future risks associated with temperature rise in most regions of the world. Switzerland is one country that wants a UN group to be formed to explore such an option. SRM won’t have to replace any existing mitigating efforts. It would be an additive component of decarbonisation.

SRM is an attractive solution to global warming. It would require relatively less radical behavioural change and economic adjustments. That could be music to the ears of developing nations. They often have to spend more than they have since they sometimes bear the brunt of climate change. While countries do understand the risks, it would be equally dangerous to sit back and not explore unique options.

COUNTERVIEW: Too many unknowns

The common refrain from sceptics is that it’s just too risky. There’s too much we still don’t know about what will happen if we deflect a portion of the sun’s rays. The planet does need a good amount of sunlight to survive. We’re in the Goldilocks zone for a reason. Blocking out a portion of the sun’s rays could have long-lasting effects on low and middle-income countries even though they’re on the frontlines.

But let’s assume we do adopt this technique. How will it be regulated? Who will regulate it? If we think of SRM as trying to change the temperature on the earth’s thermostat, who should be given the power to do that? There’s no comprehensive international set of laws for this. This itself is reason enough to be sceptical. There could be uninformed, unilateral actions that force countries to react quickly.

Just on a scientific level, some see SRM only as a bandage-type solution to the climate crisis. There’s a fear that countries would reduce their decarbonisation efforts. One group has called for an end to investing in research on SRM. It’s just too risky to the planet’s ecology, they say. It’s what critics of SRM repeatedly point out – there are just far too many questions than answers at this point.

Reference Links:

  • White House cautiously opens the door to study blocking sun’s rays to slow global warming – EENews
  • Expert panel finds many questions on solar radiation modification, but no quick answers to climate crisis – UNEP
  • Solar radiation management – risks from reversing climate change – Swiss Re
  • Solar Geoengineering Is Coming. It’s Time to Regulate It. – Foreign Policy
  • New report explores issues around solar radiation modification – UNEP

What is your opinion on this?
(Only subscribers can participate in polls)

a) Solar Radiation Modification (SRM) is a good approach to combat global warming.

b) Solar Radiation Modification (SRM) isn’t a good approach to combat global warming.


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