The REAL STORY of Climate Skeptics New Favorite Graph

- This may be climate skeptics' favorite graph.

And at first glance, it seems to show

that climate change is just a part of Earth's natural cycle.

And in some ways it is.

Earth has always warmed and cooled,

but according to its natural cycle,

we should be in the beginning stages

of a gradual cooling trend, eventually leading

to another ice age.

But we're not.

- We've totally broken the ice age cycle

and we're not going back into another ice age.

- The reason for this is simple.

We've added around 50% more carbon dioxide

to the atmosphere than in previous warm periods.

But this is where things get confusing.

When we look back at Earth's past climate,

CO2 doesn't seem to be the thing that kicks off the warming.

In fact, temperatures start rising first

and carbon dioxide levels follow every single time.

So does that mean CO2 doesn't actually

determine global temperature?

And if not, could there be something other than fossil fuels

behind global warming today?

Let's get to the bottom of it.

More than 70% of US citizens today agree

that the earth is warming.

And that's not really surprising

because the evidence is everywhere.

Glaciers and sea ice are disappearing,

Antarctica is getting greener,

and days of extreme heat have increased dramatically.

What fewer people agree on is why. Zeke Hausfather is a

climate scientist who is frequently in the media,

including on this show.

He told us the two most common arguments he gets from

climate skeptics are: one, the climate has always changed,

and two, it's the sun.

And the reason these arguments are so compelling is