Richard Lindzen

It was before...

Look, panicking, I have no idea.

No, what happened was there was, I would say, with the first Earth Day, 1970, there was a real change in the environmental movement.

It began to focus much more strongly on the energy sector and much less on saving the whales.

And there was a big difference.

I mean, the energy sector involved trillions of dollars.

The whales, not so much.

And at that time, it was cooling this global mean temperature, which doesn't change much.

But, you know, you focus on one degree, a half degree, so it looks like something.

And it was cooling from the 1930s.

1930s were very warm, and it was getting cooler until the 70s.

And that's why they were saying, well, this is going to lead to an ice age.

And they focused on that for a while.

And then in the 70s, and at that time, well, what do you say if you're worried about an ice age?

They said, well, it will be the sulfates emitted by coal burning because that reflects light, and the less light that we get, the colder we'll get.

But then the temperature stopped cooling in the 70s and started warming.

And that's when they said, well, you have to now scare people with warming, and you can't use the sulfates anymore.

Scientists called Suki Manabe showed that even though CO2 doesn't do much in the way of warming, doubling it will only give you a half degree or so.

But if you assumed that relative humidity stayed constant so that every time you warmed a little, you added water vapor, which is a much more important greenhouse gas, you would double the impact of CO2.

which now gives you a degree, which still isn't a heck of a lot, but still it was saying you could increase it.