[Right Wing Assault]

So what’s happened in this country is that we’re substituting natural gas for coal. As a result reducing pollution and also reducing global warming, if that is what you want.

Then...

We know that the carbon dioxide has gone up by thirty percent during the last hundred years. That’s due to human activities, that’s quite clear. The question is what effect that has had on the climate. That’s not clear. Whether the carbon dioxide actually caused the warming, we don’t know.

He says natural gas reduces global warming due to its lesser carbon content.

Then...

He says we don't know whether carbon dioxide caused the warning.

A bit of a contradiction there.

[JeanLM]

Don’t think He said that natural gas should have reduced global warming. He said that its use has reduced CO2 released versus using coal. His point is the CO2 connection to warming is unproven and that climate is too complicated to make predictions about any net effects.