[MD] Global Warming: Science or Politics?

[Squonkriff at aol.com]

Dear Platt,
May i ask you an additional question please regarding this issue?
 
The background:
That the Earth's climate is and has been, over geological  time, thermally 
fluctuating seems to be broadly agreed upon.
However, the preconditions for thermal fluctuation (TF) are disputed:
1. Natural Solar systemic cycles.
2. Technology.
Assuming TF is preconditioned by the relationship between Earth's orbit and  
the Sun over geological time (1), then technological influences (2) may be 
ruled  out.
 
Here is my question:
How may we be sure that present TF is not being catastrophically enhanced  by 
technological influences:
3. 1 + 2. ?
 
Best,
Mark