There is scientific evidence that demonstrates there is some impact from human activities. However I don't think the evidence is conclusive.

We need to deter Putin from further actions because this is a very real threat.

In Maidan Square right now, you see thousands of Ukrainians protesting the Russian occupation of Crimea. So this is a Russian protest by Ukrainians who want their sovereignty. They want their freedom and they're protesting what Russia did in Crimea.

If we were to impose greater sanctions on economic sectors, I think we could have a significant impact on Putin.

Governor Romney is suffering from political amnesia.

You can see the actions that the Russians are trying to take in eastern Ukraine. And so it's so important that we take actions to deter further Russian aggression against the Ukrainian people.

As a former attorney general. I have the greatest respect for the criminal justice system. But it is not good at intelligence gathering.