A solar ring around the Earth made of solar panels can provide limitless solar energy for hundreds of years. Another application is the protection of the planet's surface--a solar ring can help protect against massive solar flares that may interfere with life on Earth. Solar shading can also alter temperatures and weather on the surface as needed.
If it works as proposed, I think that it would be a good idea to try this. If we are able to reduce greenhouse gasses with this method, I think it is worth a shot because the earth is quickly heating up and the ice caps are rapidly melting. Anything that could help reverse the process or slow it down would be greatly beneficial to our planet.