The Earth's magentic field has been weaking recently, and the sun's magnetic field has been weaking recently, and it is a known fact that when either of these magnetic fields weaken (let alone both of them at the same time) that more cosmic rays reach the Earth - and indeed, throughout the past several decades there has been a continuously-increasing quantity of cosmic rays reaching the Earth - and it is also a known fact that cosmic rays produce C02, and that C02 causes global warming. So how do we know whether or not a huge portion of global warming is being caused by the C02-producing cosmic rays rather than human activitis? Obviously human activities do produce some amount of C02, but has an effort been made to determine how much of a contributor this is, compared to the C02 from cosmic rays?
I tried Googling for stuff like "do cosmic rays cause global warming" but the only results I am finding are things which discuss some theory about cosmic rays seeding clouds (Henrik Svensmark's theory), which is not what I am referring to. I could not find a single article that discusses - or tries to debunk - the possibility of global warming being caused by the C02-producing cosmic rays. There might be one somewhere in the search results, but I only have so much time that I am willing to spend digging through Google. Does anyone have an argument against this theory?