Our oil problems are only going to get worse. Our trade balance is only going to get worse. So we have to slow the growth of U.S. oil consumption, particularly imported oil consumption.

The way things are going, we are not too far from the day when it will take an hour's labor just to pay for the gasoline to get to the job.

So we in Congress have a very clear choice. We can take largely symbolic action and sit back and fiddle while Americans burn more gasoline. Or we can pass concrete, effective legislation that will save consumers money while significantly reducing U.S. oil consumption.

But our energy woes are in many ways the result of classic market failures that can only be addressed through collective action, and government is the vehicle for collective action in a democracy.

The damage that climate change is causing and that will get worse if we fail to act goes beyond the hundreds of thousands of lives, homes and businesses lost, ecosystems destroyed, species driven to extinction, infrastructure smashed and people inconvenienced.

If we're concerned about climate change as a country, we should have policies that make sure our great-grandchildren have a planet that's healthy and strong.

Nuclear tests poison the environment - and they also poison the political climate. They breed mistrust, isolation and fear.

Autoimmunity is probably the next frontier. The majority of cases of autoimmune disease result from a complex genetic problem that has environmental influences. It is a colossal task for the immune system to maintain tolerance to self and yet be ready to react to everything in the world around us.