Could Kessler Syndrome be used to control the temperature of the Earth?

Question

Imagine launching a bunch of tiny reflective particles in orbit. This would reflect sun away from earth. Based on the orbit, you could have a swarm only go over certain parts of the earth. Or only cover the earth for part of the day.

They all eventually fall out of orbit and burn up. This also makes it something that isn't permanent and could be replenished as needed.

The source for the material could be an asteroid that gets broken up in orbit or something launched from earth like metal powder, glitter, Styrofoam etc. Or even made by grinding up old satellites.

When launching satellites or people into space, a blowtorch could be placed on the front of the launch vehicle to burn a hole through the swarm. Or the swarm could be tracked and launches planned accordingly.

The only big drawback would be blocking the view of the moon and stars and sun. But if the swarm is only on the bright side of earth it would just make the sun and moon look a little weird in the day time. Maybe add a bit of sparkle to the sky.

Answer 1

Yes, but not in any sensible manner.

Space mirrors could certainly work to manage Earth temperature, the issue is that to do meaningful amounts they need to re-direct a reasonable % of the light reaching Earth, making the needed area a sizable % of earth's surface. This produces designs with areas measuring 1000s of km on a side and weighing millions of tonnes.

These designs normally assume placement at Earth/Sun L1 point. This last bit is important, since at L1 our massive and expensive structure is shading 100% of the time. Putting the same amount of 'shade' in LEO means more than half of it is either behind earth, or off to the side, needing more 'stuff' launched. There is no way to have an solar shade orbit that stays on the 'day' side*.

Designs to date also assume an active structure that keeps facing the right direction to provide shade. If uncontrolled, flat shapes will often not be shading effectively and non flat shapes will be mass inefficient - both options increasing needed mass to orbit. Worse, some shapes may stabilize end on to Earth, making optimally inefficient shades. It would be easy for the massive number of rocket launches to get millions of tonnes of shade material aloft to have more climate effect than the shade itself.

Collisions between shades is also a problem, since it will tend to convert them from something efficient into something less so. And for very large numbers of small shades collisions are inevitable due to how all orbits not in the same plane will intersect twice, and the way these objects will be acting as solar sails so will not stay in original orbit.

Which yes will make a kessler cascade of the question, but leave earth with a debris ring that may in fact make things worse! A poorly operating LEO shade system can end up hindering cooling on the night side of earth, reflect light onto earth rather than away to space or block visible light but re-radiate infra red to Earth anyway.

Further, a LEO system will tend to re-enter as on average collisions will remove orbital energy, and several millions tonnes of shade material in the upper atmosphere will be complicated to deal with.

So, while a massive deliberate Kessler event could impact the climate it certainly would not be 'control'.

Answer 2

Let's assume that your question can be restated as:

Can we control the temperature of the planet by initiating Kessler Syndrome?

In this case, the answer is "No".

Control is a means of limiting or regulating something - in this case, the temperature of the Earth.

There are two types of control: closed-loop control and open-loop control. A closed-loop controller or feedback controller is a control loop which incorporates feedback, in contrast to an open-loop controller or non-feedback controller. Because Kessler Syndrome is a run-away cascade of satellite destruction that we can't control once it's initiated, we can't implement closed-loop control with it. This leaves open-loop control.

Open-loop control of the temperature of the Earth by triggering Kessler Syndrome would require accurately modeling the cascade of destruction, modeling the Earth's climate, and combining the two models to prove that the generated space debris will alter the climate to achieve the desired climate outcome. Even if the models predicted that the outcome would be desirable, you would also need to reach a consensus that the models are accurate and can be trusted.

Both the destruction-cascade model and the Earth's climate model will need to deal with chaotic behavior which is inherently difficult to model. It is beyond unlikely that either model could be implemented with enough accuracy to enable open-loop control. Even if they could be, it is unlikely that enough people could be convinced to trust the models. So, open-loop control would not be possible either.

Since neither type of control is possible, it is not possible to control the temperature of the planet by initiating Kessler Syndrome.

However, if your question is really about launching reflective glitter into orbit to control the Earth's temperature, then it might be possible to implement closed-loop control. Solar Radiation Modification is "a thing" - albeit a somewhat controversial thing. There is even a recent congressionally-mandated report on "solar and other rapid climate interventions" which you can find here.