Climate Change and Ice Core Data Analysis

The first ice core survey took place in Vostok in the Antarctic.

What it found, as Al Gore correctly points out,

was a clear correlation between carbon dioxide and temperature.

We're going back in time now, 650,000 years.

Here's what the temperature has been on our Earth.

Now one thing that kind of jumps out at you is,

did they ever fit together?

Most ridiculous thing I've ever heard.

The relationship is actually very complicated,

but there is one relationship that is far more powerful than all the others,

and it is this.

When there is more carbon dioxide, the temperature gets warmer.

Al Gore says the relationship between temperature and CO2 is complicated,

but he doesn't say what those complications are.

In fact, there was something very important in the ice core data

that he failed to mention.

Professor Ian Clark is a leading Arctic paleoclimatologist

who looks back into the Earth's temperature record tens of millions of years.

When we look at climate on long scales,

we're looking for geological material that actually records climate.

If we're to take an ice sample, for example,

we use isotopes to reconstruct temperature,

but the atmosphere that's imprisoned in that ice,

we liberate and then we look at the CO2 content.

Professor Clark and others have indeed discovered, as Al Gore says,

a link between carbon dioxide and temperature.

But what Al Gore doesn't say is that the link is the wrong way around.

So here we're looking at the ice core record from Vostok,

and in the red we see temperature going up from early time to later time

at a very key interval when we came out of a glaciation.

And we see the temperature going up, and then we see the CO2 coming up.

CO2 lags behind that increase.

It's got an 800-year lag, so temperature is leading CO2 by 800 years.

There have now been several major ice core surveys.

Every one of them shows the same thing.

The temperature rises or falls,

and then, after a few hundred years, carbon dioxide follows.

So obviously carbon dioxide is not the cause of that warming.

In fact, we can say that the warming produced the increase in carbon dioxide.

CO2 clearly cannot be causing temperature changes.

It's a product of temperature. It's following temperature changes.

The ice core record goes to the very heart of the problem we have here.

They said, if the CO2 increases in the atmosphere as a greenhouse gas,

then the temperature will go up.

But the ice core record shows exactly the opposite.

So the fundamental assumption,

the most fundamental assumption of the whole theory of climate change

due to humans is shown to be wrong.

But how can it be that higher temperatures lead to more CO2 in the atmosphere?

To understand this, we must first restate the obvious point

that carbon dioxide is a natural gas produced by all living things.

Few things annoy me more than to hear people talking about carbon dioxide as being a pollutant.

You're made of carbon dioxide. I'm made of carbon dioxide.

Carbon dioxide is how living things grow.

What's more, humans are not the main source of carbon dioxide.

Humans produce a small fraction in the single digits percentage-wise

of the CO2 that is produced in the atmosphere.

Volcanoes produce more CO2 each year

than all the factories and cars and planes and other sources of man-made carbon dioxide put together.

More still comes from animals and bacteria,

which produce about 150 gigatons of CO2 each year

compared to a mere 6.5 gigatons from humans.

An even larger source of CO2 is dying vegetation,

from falling leaves, for example, in the autumn.

But the biggest source of CO2 by far is the oceans.

Carl Wunsch is professor of oceanography at MIT.

He was also visiting professor in oceanography at Harvard University and University College London

and a senior visiting fellow in mathematics and physics at the University of Cambridge.

He is the author of four major textbooks on oceanography.

The ocean is the major reservoir into which carbon dioxide goes

when it comes out of the atmosphere or from which it is re-emitted to the atmosphere.

If you heat the surface of the ocean, it tends to emit carbon dioxide.

Similarly, if you cool the ocean surface, the ocean can dissolve more carbon dioxide.

So the warmer the oceans, the more carbon dioxide they produce,

and the cooler they are, the more they suck in.

But why is there a time lag of hundreds of years

between a change in temperature and a change in the amount of carbon dioxide

going into or out of the sea?

The reason is that oceans are so big and so deep,

they take literally hundreds of years to warm up and cool down.

This time lag means the oceans have what scientists call a memory of temperature changes.

The ocean has a memory of past events running out as far as 10,000 years.

So, for example, if somebody says,

oh, I'm seeing changes in the North Atlantic,

this must mean that the climate system is changing.

It may only mean that something happened in a remote part of the ocean

decades or hundreds of years ago

whose effects are now beginning to show up in the North Atlantic.

The current warming began long before people had cars or electric lights.

In the past 150 years, the temperature has risen just over half a degree Celsius,

but most of that rise occurred before 1940.

Since that time, the temperature has fallen for four decades and risen for three.

There is no evidence at all from Earth's long climate history

that carbon dioxide has ever determined global temperatures.

But if CO2 doesn't drive Earth's climate, what does?