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
?