Climate ‘fix’ could deplete ozone Unit 3 Ideas in Context P7(H) Paper Paul Kerr The Derby High School, Bury.

Climate ‘fix’ could deplete ozoneUnit 3 Ideas in Context P7(H) Paper

Paul KerrThe Derby High School, Bury

What is climate and weather?

Climate – average weather conditions over a period of at least 30 years Weather – current

conditions in the atmosphere, e.g. Rain. The Sun drives all of the Earth’s weather systems

Changing temperatures

Correlation?

• Temp & C02 level rising • Ice core evidence confirms

similar changes in the past • Scientists know C02 warms

the atmosphere • Computer models show

global temperatures are related to rising C02 levels

Cause? – The Greenhouse Effect

Changing Climates - Effects

• Natural factors– Distance from the Sun changes– Amount of radiation from the

Sun changes in cycles– Volcanic eruptions increase C02

levels• Human factors– Emission of greenhouse gases

C02, CH4, H20 vapour

Changing Climates - Risks

• Melting ice (glaciers and ice caps)

• Rising sea levels (coastal changes)

• Extreme weather• Effects on food and water

resources• Human health (e.g. Malaria)• Financial (e.g. Insurance)

Changing Climates - Action

Use the car less.... Turn the heating down.... Use non-fossil fuels....

Buy local produce.... Reduce air travel.... Recycle more... Avoid standby...

1991 Mount Pinatubo Eruption

Volcanic CoolingSulfate (S02) particles reflect sunlight (Albedo) to counteract Global Warming

Atmospheric layers

Sulfates provide a surface on which chlorine gases in POLAR stratospheric clouds can become activated causing chemical reactions that destroy Ozone (03) molecules

Ozone (03) protects us by absorbing harmful UV radiation. After the eruption of Mt Pinatube 03 decreased over Antarctica

Sulfate Injection

• Geo-engineering or climate-engineering is a deliberate method of changing the Earth’s climate to try to counteract Global warming

Military jets and tanker aircraft or

high altitude balloons could deliver sulfates

into the stratosphere.

Clouds form due to sulfate injection.

Up to 90% reflection occurs, enhancing

Albedo.

The Ozone LayerOzone production

Ozone absorbs dangerous UV radiation, protecting us below

Ozone destruction

Sulfates activate chlorine gases in polar clouds.

Cl + O3 → ClO +O2

A free oxygen atom can release the chlorine atom to do further damage ClO + O → Cl +O2

Dr Simone TilmesI measured O3 levels in the

atmosphere and used computer simulations to estimate future 03

loss if sulphate injections continued

Over the next 20yrs this

could destroy as much as ¾ of the 03 layer over the Arctic

Arctic – North Pole

Dr Simone TilmesThe expected recovery of ozone

over Antarctic could also be delayed by about 30 to 70 yrs

Sep 1979 Oct 2007

2050 fully repaired?

(2080 – 2130?)

1987: Montreal Protocol. World agreement to ban CFC’s (Cl, F and C).

Antarctic – South Pole

Dr Simone TilmesMore research is needed before

society attempts global geo-engineering solutions in the

future.

We should not rule out this approach. Politicians will have to decide what is most important.

They need to know what is good and bad about it.

Risks (bad) v Benefits (good)

Sulfate injection

Benefits• Reduce Global Warming

Risks• Ozone depletion• Holes in Ozone layer• Increased UV exposure

leading to increased cases of skin cancer

Cancelling Sulfate injection

Benefits• Ozone layer protected

Risks• Global warming• Melting ice caps and glaciers• Rising sea levels• Extreme weather• Disease• Financial costs

?