What is wrong with this idea?
Could installing a shade fix the climate crisis?
No thats not a joke. Sometimes simple answers work, sometimes they don't. It seems the whole point of reducing carbon emissions is to change the absorbtion ratio of the solar energy that hits the earth. While its probably a good idea to maintain the atmospheric balance of gasses in ratios similar to those we evolved in, I suggest that the amount of solar energy the earth absorbs can be addressed seperately and much more directly.
I am aware that the various space programs would not have the funds to attempt such an endevour at this time. I am not so sure that it would be beyond our current technical expertise. I am no expert here, just a layperson. I would like to see a more robust space program in the future, and ponying up the funds to install a solar orbital with a earth - synchrous orbit whose purpose is adjustably deflecting solar energy could be an excellent oppritunity for it to cut its teeth on.
It would also cost a lot to maintain. It would need fuel for orbital corrections. It would need repair/upkeep for degradation problems. It is also likely that it could fail catastrophically, we would need to be able to replace it quickly. Despite maintenence costs, it seems that its impact would be quicker and more direct, and a much better step in controlling our climate on a global scale.
If we installed additinal solar orbitals that could reflect solar energy toward us, we would have direct control over a range of solar energy reaching our planet. Right now that would be bad, but if we start slipping towards an ice age in a millenia, I'd want a couple of those too.
Cleaning the panes of glass on a greenhouse will change how hot it gets, but installing a shade would have a much greater effect.