The Earth's climate has been changing for ~4.5B years, without the help of humans.

 It would be interesting, if those who are claiming humans caused climate change, to provide some scientific data as to how just how much, humans are contributing, in comparison to natural variability. 

 Is it 1%/99%, 50%/50%, 99%/1%? 
Natural gas, as does coal combustion,  produces greenhouse gases such as H2O, CO2, etc.
One of the simplest way to note significant global temperature change is noting sea levels. Oceans cover most of the earth's surface, & H2O expands with temperature. If there would be abnormal heating, sea level increases would show an acceleration in their rise (going on since the last ice age).

Long term sea level tidal gauge date shows a virtually straight line rise over the last 100+ years, indicating that pretty much all the climate change is due to natural variations.

Prescribing drugs for the wrong, or no illness, can be dangerous.