Lawns May Contribute to Global Warming

The global carbon concentrations in the atmosphere beg to differ. Climate change isn't liberal propaganda. Only people whose political views are put in jeopardy by it and idiots deny it. Temperatures rise and fall, but we don't know enough about that process to predict what's going to happen. What we KNOW is that humans are making a huge impact on the environment and that our current lifestyles are unsustainable.

If we don't know how temperatures rise and fall, then how do we know we're having an effect on the temperature?