climate change – new science – old arguments. overview some old science the big experiment …...

Climate Change

– New Science– Old Arguments

Overview

Some old science The big experiment … The Earth’s climate Is the Earth warming? Does it matter? What can we do about it?

So what is the -

‘Greenhouse effect’ ?

It’s all just a bit of physics!

Actually it started with

Joseph Fourier (1820’s)

John Tyndall (1860’s)

Svante Arrhenius (1890’s)

So what is the (Earth’s) ‘Greenhouse effect’ ?

Climate Science 101

“The Earth should be a lot colder than it is”

Joseph Fourier ~1820

Climate Science 101 Fourier used basic physics to calculate that

the Earth ought to be a frozen snowball!

Climate Science 101

He realised that somehow the atmosphere must be trapping heat

Climate Science 101

Tyndall found it was the water vapour and carbon dioxide gases in the air

John Tyndall ~ 1860

Climate Science 101

Earth’s energy balance Svante August Arrhenius worked it out in 1896

Earth’s energy balance Svante August Arrhenius worked it out in 1896

“The Earth’s average temperature should be about –18oC”

?

Climate Science 101

Climate Science 101

Earth’s energy balance Svante August Arrhenius worked it out in 1896

“CO2 and H2O absorb heat and send enough back to Earth to raise the temperature by

+33 degrees!”

Climate Science 101

Earth’s energy balance Svante August Arrhenius worked it out in 1896

“So what will all the CO2 we are putting in the atmosphere do?”

?

Climate Science 101

Earth’s energy balance Svante August Arrhenius worked it out in 1896

“If we double the CO2 it could raise the temperature by about 5 degrees!”

That’s not all that far off modern IPCC estimates of 2°C – 5°C

“That will make Sweden warmer – good !”

Climate Science 101

The Earth’s temperature is determined by the balance between incoming solar radiation from the Sun…

The Earth’s temperature is determined by the balance between incoming solar radiation from the Sun…

and outgoing ‘heat’ radiation into space

Climate Science 101

A little physics Earth’s energy balance

– Two simple laws of physics enable us to figure out the energy balance: The Stefan-Boltzmann law...

I = εσT4 Wien’s law... λmax = 0.0029/T

– S-B just tells us how much heat a hot object radiates.

– Wien tells us what sort of radiation it will be.

Don’t panic!

(fortunately others have done the hard work for us!)

Climate Science 101

The H2O and CO2 in the atmosphere trap some of the IR and so the Earth heats up until it emits enough IR...

… to balance the incoming solar radiation

At present this happens at around 15oC

If less energy escapes than comes in we get warmer.

Climate Science 101

Climate Science 101

Even though the H2O and CO2 are only a tiny proportion of the air, they absorb the outgoing infrared (‘heat radiation’)

But how can CO2 which is only 0.04% of the atmosphere do that? (Or 390 ppm)

Simple: Nitrogen and Oxygen do not absorb infrared (IR) while H2O and CO2 do.

Climate Science 101

(There are good physics answers to that question but ...)

Here’s a simple analogy: Water allows all visible light through But ink blocks it ....

Climate science

300 ppm (or 0.03%) might not sound like much, but here is the effect of adding 300 ppm of ink to a glass of water:

Climate Science 101

The water is like the atmosphere – it has no effect on the light

The ink absorbs visible light just like the carbon dioxide absorbs infrared light

If we could ‘see’ in infrared the atmosphere would look quite opaque!

The atmosphere traps heat and warms the Earth

Climate Science 101

Climate Science 101

This is a like a greenhouse...

So it is called the “Greenhouse Effect” It keeps the Earth at a warm +15oC (average)

instead of that freezing –18oC

Greenhouse Effect = +33oC

Our place in space

Steady temperature:

Heat in (from you)

=

Heat out (IR radiation)

Climate Science 100

More blankets …

Harder for heat to escape …

You get warmer until …

heat in (from you)

equals heat out (IR radiation)

Climate Science 100

+33 degrees

+33 + ? degrees

The Biggest Experiment

on Earth…ever!

The BIG Experiment

Started 200 years ago Global scale Involves all of us Costs a fortune (By-passed the ethics committee) Results are coming in fast! Hypothesis is being confirmed (Could be some unintended consequences) What is it? . . . .

The Big Experiment is... … the release of the carbon stored by solar

energy over 100 million years ...

(In the Carboniferous era from around 300 Mya to 200 Mya)

Solar energy converted CO2 in the air into plant growth (forms of carbon)

The Big Experiment is... … the release of the carbon stored by solar

energy over 100 million years …

in only centuries

That is, a MILLION times faster.

We have to ask whether it might have an effect!

ie. 600,000,000,000 tonnes

The Big Experiment We have increased atmospheric CO2 by 40%

and now we are waiting to see what the climate will do!

The Big Experiment

Is the Earth warming?

2010

”But the warming has stopped”

Overview

Climate science 101 – Greenhouse effect The big experiment …

The Earth’s changing climate Is the Earth warming? Does it matter? What can we do about it?

Earth’s climate – looking at the past

Climate change IS natural … BUT!

Hothouse Earth

Snowball Earth

In the last 500 million years the climate has swung between ‘Hothouse Earth’ and ‘Snowball Earth’

Earth’s climate

Earth’s climate

The Earth: 500 million years ago to

20 million years ago

Hothouse Earth

Snowball Earth

Earth’s climate

20 Mya

Earth’s climate

The Earth 20 million years ago About 2oC or 3oC warmer than today Sea about 50 metres higher

Earth’s climate

The Earth today

Earth’s climate

Do we really want to go here?

Earth’s climate

The Earth 18 thousand years ago About 5oC colder than today Sea about 100 metres lower

Earth’s climate

Today

Earth’s climate changes – but why?

Over millions of years: Continental movement Changing atmosphere – plant life Changes in greenhouse gases Meteor impacts Massive volcanic activity Changes in the Earth’s orbit Changes in the Sun’s output

Earth’s climate changes – but why?

Over thousands of years (the last 1 million): Volcanic activity (small) Changes in the Earth’s orbit Changes in the Sun’s output Changes in greenhouse gases

Earth’s climate changes – but why?

Earth’s climate

Earth’s climate

Earth’s climate

The orbital wobbles triggered the changes The carbon dioxide AMPLIFIED them …

Earth’s climate and Carbon Dioxide

Solar warming

More carbon dioxide into atmosphere

Higher temperaturesMore

greenhouse warming from carbon dioxide

Positive feedback!

Earth’s climate – looking at the past

The last ‘interglacial’ – similar to current climate.

Maybe ~2°C warmer than last century average...

last interglacial period when sea level peaked at around 10 metres higher than today. His findings suggest that at one point the sea rose 3 metres within 50 to 100 years.”

“Paul Blanchon's team at the National University of Mexico has been studying 121,000 year old coral reefs in the Yucatan Peninsula, formed during the

Temperatures in that interglacial were only a couple of degrees warmer than the 20th C.

July2009

10 m higher than today

Sea level in the last inter-glacial

Today

Earth’s climate – looking at the past

Climate change in the time of human civilization has been very minor: ±½°C.

Talk of ‘warm Greenland’ or the ‘Little Ice Age’ is just a distraction.

The climate change we are facing is far more drastic than anything humans have experienced.

Earth’s climate – looking at the past

2010

Earth’s climate – looking at the past

+3°C

Pliocene

Earth’s climate – looking at the past

Pliocene

Sea levels between 25 and 75 metres higher than today

Earth’s climate

There is much more! Some past abrupt

climate changes have been linked to sudden releases of greenhouse gases

National Academies Press (USA)

Earth’s climate

Many extinction events followed a rise in CO2 levels

Not ‘proof’, but surely cause for concern!

Adapted from: Under a Green Sky – P.Ward, Smithsonian

Overview

Climate science 101 – Greenhouse effect The big experiment … The Earth’s climate

Is the Earth warming? Does it matter? What can we do about it?

really

^

‘Sceptics’ and ‘deniers’

Scientists are always sceptical If you can show a theory is wrong that is great! “If the facts change, scientists change their

minds” POLITICS: Chose only the facts that ‘prove’ your case … and stick to them whatever! (Look at what happens if a politician changes her mind!)

“Climate-change denial could have disastrous consequences if it delays global action to cut carbon emissions. Denialism is gaining popularity because people have difficulty differentiating deniers’ twisted arguments from the legitimate concerns of genuine sceptics.”

Christopher Monckton of Brenchley’s version of temperature trends

Title Let’s put Monckton’s red line on the

NASA graph

Typical Bolt:

“In fact, if Gillard shut down our economy completely and shot every burping cow , the temperature by 2100 would fall just 0.01 degrees. All pain, zero gain.”

Herald-Sun 12 March 2011

‘Sceptics’ and ‘deniers’

…if nobody else did anything!

“In the end, he found Bolt's writings were calculated to offend and inflame negative views in his readers, omitted crucial information that would have countered the arguments he was making, and were full of errors. He also found that they were reasonably likely to offend, insult, intimidate and humiliate …”

The Age Editorial 30 Sep 2011 (The “White Aboriginal” case)

‘Sceptics’ and ‘deniers’

Satellites can measure the heat escaping to space …

Low radiation High radiation

Is the Earth warming?

Is the Earth warming?

… and IT IS LESS THAN THAT COMING IN from the Sun!

The Earth must warm until they balance!

Reflected visible radiation Emitted IR radiation

Is the Earth warming?

Is the Earth warming? The Ocean

It is the heat in the ocean that drives the weather

More heat

warmer water

more evaporation

more water vapour

more storms and rain

Is the Earth warming? Storms

Pakistan 2010

Beijing June 2011

China August 2010

Cyclone Yasi Feb 2011

Cyclone Yasi Feb 2011

Cranbourne

Brisbane

Ethiopia

Russia

Is the Earth warming? Global temperatures

Is the Earth warming? Glaciers

Is the Earth warming? Antarctica

Is the Earth warming? Greenland

Is the Earth warming? Arctic Sea Ice

Arctic Sea Ice September 2011

Is the Earth warming? Arctic Sea Ice

Is the Earth warming? Sea levels

Is the Earth warming? Sea levels

Is the Earth warming? Floods

“The year 2010 was one the worst years in world history for high-impact floods. But just three weeks into the new year, 2011 has already had an entire year’s worth of mega-floods. “ – Meteorologist Jeff Masters

THE world has just five years to make ''urgent and radical policy changes'' or lock in dangerous climate change, the world's leading energy agency has warned, sparking a debate about whether Australia should shift to gas or renewable energy.

Agency chief economist Fatih Birol said if by 2017 there is not a start to major new clean infrastructure investments ''the door to 2 degrees will be closed''.

''I am very worried,'' he said, ''if we don't change direction now on how we use energy, we will end up beyond what scientists tell us is the minimum. The door will be closed forever.''

We find that in the set of scenarios with a ‘likely’ (greater than 66%) chance of staying below 2 °C, emissions peak between 2010 and 2020 and fall to a median level of 44 Gt of CO2 equivalent in 2020 (compared with estimated median emissions across the scenario set of 48 Gt of CO2 equivalent in 2010). Our analysis confirms that if the mechanisms needed to enable an early peak in global emissions followed by steep reductions are not put in place, there is a significant risk that the 2 °C target will not be achieved.

"The bad news just got worse: A new study finds that reining in greenhouse gas emissions in time to avert serious changes to Earth's climate will be at best extremely difficult. Current goals for reducing emissions fall far short of what would be needed to keep warming below dangerous levels, the study suggests. To succeed, we would most likely have to reverse the rise in emissions immediately and follow through with steep reductions through the century. Starting later would be far more expensive and require unproven technology".

Nature Climate Change | Letter Emission pathways consistent with a 2 °C global temperature limit Joeri Rogelj et.al. 23 October 2011

The Age 5 Nov 2011

Overview

Climate science 101 – Greenhouse effect The big experiment … The Earth’s climate Is the Earth warming?

Does it matter? What can we do about it?

Sea level rises drown all our major coastal cities

Droughts and floods ruin agricultural land and cause famine

Biodiversity lost as species fail to adapt Water supplies (from Himalayan glaciers) to

the great Asian food bowl dry up Climate refugees overwhelm developed

countries

Does it matter?

Does it matter?

“We have already overstepped three of nine planetary boundaries and we are at grave risk of transgressing several others”

Does it matter?

Does it matter?

“A bit of warming won’t hurt us” WRONG, WRONG and WRONG! It won’t be “a bit” It’s not the “warmth” – it’s the results of it It will lead to a very different Earth that

hasn’t been seen for millions of years!

Could we be wrong?

Science always has some “uncertainty” It is the nature of science to be “sceptical” But the more we find out, the less the

uncertainty Only a tiny handful of climate scientists are

not convinced Most of those have vested interests (Plimer)

or strong political (Lindzen) or religious (Spencer) views

ALL major scientific academies and institutions around the world have made statements to the effect that climate change is real, human caused, and requires urgent action

• Would you get on this aeroplane if 1 out of 10 engineers found dangerous cracks in the wings?

Uncertainty in Science

• How about if 9 out of 10 engineers said there were dangerous cracks in the wings and 1 said they didn’t matter?

Uncertainty in Science

That’s about the proportion of scientists saying climate change is dangerous!

Actually it is more like over 97%

“This image was digitally altered!”

That’s about the proportion of scientists saying climate change is dangerous!

And if it’s NOT a big hoax?

But why should we do anything while nobody else does?

Many are doing FAR more than us!

Trial and error in a carbon world Adam Morton Sat Age November 12, 2011

News Ltd consistently avoids or distorts climate issues:

Prince Frederik visits wind farm

Media Bias

Media Bias

But no mention of the Vestas connection and the comments about the 2 km policy!

Media Bias

The Coal Seam Gas issue:

Emissions “up to 87% smaller”

Media Bias

The Coal Seam Gas issue:

Emissions “up to 87% smaller”

Media BiasHow to get 87% less!

Media Bias

Radio 2GB anti C tax or anti climate science

(Aug – Nov 2011)

Radio 2GB pro C tax or pro climate science

(Aug – Nov 2011)

Media Bias

Overview

Some old science The big experiment … The Earth’s climate Is the Earth warming? Does it matter?

What can we do about it?

BUT THERE IS GOOD NEWS!

We CAN move to a sustainable future

www.beyondzeroemissions.org