1. The fragility of spaceship earth
web: kevinanderson.info
Kevin Anderson
Professor of Energy & Climate Change

2. Coming to terms with our new world vision (1960s -)

3. The science behind Climate Change
What we can do about it

4. The Great Global Experiment
‘Climate Change and its Consequences’

5. Some underlying drivers of the world’s climate & weather
Gravity
Earth’s rotation
Topography
Volcanoes
Life
Solar radiation 5

6. Radiation Shortwave (solar) : from the sun; dominates incoming sources
Longwave (terrestrial) :
from the earth, dominates outgoing sources 6

7. THE GREENHOUSE EFFECT SUN EARTH ATMOSPHERE Low temperature
The Met.Office Hadley Centre
Some of the infrared
radiation is absorbed
and re-emitted by the
greenhouse gases.
The effect of this is to
warm the surface
and the lower
atmosphere
SUN
high
temperature
Some solar radiation is
reflected by the earth’s
surface and the atmosphere
Solar radiation
high temp’ source
-short wavelength
ATMOSPHERE
Solar radiation
passes through the
clear atmosphere
Terrestrial radiation
low temperature source
longer wavelength
(Infrared)
EARTH
Low temperature
Most solar
radiation absorbed -
warming the surface

8. Early Contributors
Fourier (1827) first advanced the idea that the atmosphere acts like the glass of a greenhouse (Mem de l’ Ac. R. de Sci de l’Inst de France Vol 7.)
Tyndall (~1860) first to demonstrate & quantify the impact of the greenhouse gases [infrared emitters]
Arrhenius (1896) Provided first predictions of changes in global temperature arising from increases in CO2 concentration. (Phil Trans 41, )

9. Breakdown of Warming caused by
Greenhouse Effect
without with mean
Greenhouse Greenhouse Increase
Surface
Temperature oC oC oC
Water Vapour responsible for 60-70% greenhouse effect
(~1% of atmosphere – a positive feedback of other GHGs))
Other Gases responsible for ~ 30-40% greenhouse effect
(~0.04% of atmosphere)

10. So what is changing? Drivers:
Position of the sun in relation to the earth
Volcanic eruptions
Solar cycle
Concentration of greenhouse gases

11. How do we know things are changing?
- Tree rings – 10,000 years – reflect water availability
- Ice cores –160,000 years – Oxygen isotopes and air bubbles (with CO2) provide information (e.g. 1ppm difference in oxygen isotope is equivalent to a 1.5ºC temp changes)
- Ocean sediment – million years – proportion of heavy oxygen in sea shells goes up when temperatures drop

12. Trends of main greenhouse gases atmospheric concentrations
pre-industrial ~2015/ %
concentration concentration Increase
CO2 280ppmv +400ppmv ~43%
CH4 700ppbv ~1835ppbv ~162%
N ppbv 328ppbv ~22%

13. Greenhouse Gas Flows Global flow of CO2 ~ 750 Gt p.a
Note: 1 Giga tonne (Gt) is 1000 million tonnes
Global flow of CO2 ~ 750 Gt p.a
Human emissions of CO2 ~ 40 Gt p.a.
Human CO2 added to Atmosphere ~ 18 Gt p.a
This has led to a:
… ~ 43% increase in atmospheric carbon
concentration since ~1800

14. Historical concentrations
The current CO2 concentration has not been exceeded during past yrs and…probably not during the past 5 million years
Evidence for being human made - CO2 from fossil fuels contains no 14C unlike the ‘background’ atmospheric CO2 ?
2016:

15. The Greenhouse Effect & Climate Change
The Greenhouse Effect is uncontested!
without it the earth would be ~ 33K cooler.
Climate Change is uncontested!
the balance of incoming and outgoing radiation has always fluctuated, with, for example, changes in atmospheric constituents, their relative concentrations, solar variations, etc.
Anthropogenic Climate Change is uncontested
though slightly different views exist on the degree to which the observed warming is due to anthropogenic emissions.
Future anthropogenic Climate Change is contested - a little.
the level of future warming depends on the ‘climate sensitivity’ – i.e. how much warming is likely for a doubling in CO2 concentration compared with pre-industrial levels. (IPCC likely range is 2 to 4.5°C; most likely estimate is 3°C)

16. To Conclude the Science Section:
Greenhouse effect is understood
Atmospheric concentrations of
greenhouse gases are rising
Empirical data tends to support the
science and the models
Feedbacks are, to some degree, understood (net effect exacerbates warming)

17. Where do human emissions come from ?

18. What can we do ?
Learn to live with increased climate change (adaptation)
Find ways to reduce carbon emissions (mitigation)

19. Adapt to What ? More severe weather events Destruction of Ecosystems
Flooding
Food shortages
Fresh Water shortages
Human Migration
Increased Military tension
Changes in Disease

20. Adaptation: Equity & Morals!
High Carbon emitters geographically & financially able to adapt
Low Carbon emitters suffer geographically and financially from climate change impacts - also have less political influence
____________
Today’s generation are the Cause
Tomorrow’s generation suffer the Impacts

21. Adaptation: Equity & Morals!