I am not an expert in mining but I have a hard time believing that producing and using solar panels is "far more polluting" than mining and burning coal as it is done today. I am also curious of the "ratio" of materials needed. I deal with solar after the panels have been made and delivered. Even if what you say is absolutely true, we can either make them here with much less pollution (and jobs, economic benefits, etc...) or we can buy them from China. One way or the other we are gonna buy them just like any other source of power.
I still have a very hard time believing that pollutants released into the environment are even remotely close. A solar panel will produce power for decades with no pollution beyond the manufacturing and raw materials. On the production side, I have been told the pollutants are very manageable and rarely make it into the environment.
To be clear, I am also a fan of traditional power sources but the reality is we aren't going to be allowed to build much of it until the shit really hits the fan. By then it will be too late but it seems Mexico will be glad to take our money just like all the people who sell us oil. Again, I am a fan of drilling for our own oil but it won't happen in any meaningful way either. The lawyers own the damned country and I don't see that changing anytime soon.
At least investing in solar provides us with a real tangible asset that will continue to have value for decades to come while helping alleviate our growing power issues AND we can actually do it right now, today.