And we know the solar output's not constant through time.

So those are all natural causes of climate change.

Well, the problem is that we've got very complicated forces in the climate system.

It may surprise you that it's not only climate.

Our energy sources are not sustainable.

For me, what's important.

So what needs to be done?

There's two great forces that are both volitional but inevitable.

Climate change is real.

That is the change needed to restore energy balance and prevent further warming.

And, of course, Arctic communities are toast.

We have now, and are the first generation with, the power to do this.

75 minutes.

In the U.K., the Thames Barrier protects London from storm surge.

Okay? We cannot reduce animal numbers to rest it more without causing desertification and climate change.

Don't we already know how they affect temperatures?

Climate change deniers argue that the Sun is the main cause of climate change.

less stuff.

You know, this is really an infinite thing.

We're not even slowing down.

And the same thing is true for people who are in absolute crisis. Right?

We, the people, still believe that our obligations as Americans are not just to ourselves, but to all posterity.

They've got no points of land more than about six feet above sea level.

And he used to be the USA Today Monday morning guy.

And you need to deal somehow break the link between human actions that change climate, and the climate change itself.

And I'll mention them the emission of CO2, climate change, the fact that we have the responsibility of the acceleration of the climate change.

As we see the spread of it, we see national hubs emerging.

And more CO2 causes more warming.

And there is natural variability caused by the Sun, caused by El Ninos.

Widespread water pollution and massive degradation of lakes and rivers.

Anyway, last year, I heard about the Himalayas and the melting of the (Laughter) and the melting of the glaciers because of climate change.

But fossil fuels, carbon coal and gas are by no means the only thing that is causing climate change.

They are both two branches of the same field of atmospheric science.

So, we're not sure where this story is going to end, whether it's got a happy or sad ending.

And I think it really summarizes where we are here.

You know the climate.

The game retreated northward

The whole world needs to tackle the problem of climate change together.

And even at that time, with the introduction of agriculture, 8,000, 10,000 years ago we started to see climate change.

What's new is just the degree of it.

I'm just going to talk about two things.

We see and feel the climate changes, the droughts and the flooding, the storms and the heat.

The climate is changing.

One cubic meter of wood will store one tonne of carbon dioxide.

I can't think of anything else that's happened in my lifetime that way.