Climate change an emergency

1
Climate change - an emergency?
What are the worlds leading climate scientists
telling us?
David Knight Co-ordinator, WinACC Science and
Technology Advisory Panel
2
Climate Change

• Climate change undermines
• personal, national and regional security
• the livelihoods of the poor
• human health
• overseas aid
• prosperity
• It is a fairness and equity issue between and
  within generations
• the poor in the developing countries cause it
  the least yet suffer the most.
• our actions of today greatly affect future
  generations .

3
A global mean temperature rise of 2oC would be
catastrophic. The most probable scenarios give
less than a 5050 chance of staying beneath 2oC
4
Update on IPCC TAR1 report 2001 (Smith et al.
PNAS March 17, 2009 vol. 106 no. 11 4137)
Even a 1oC increase on 1990 is far from safe
5
We collectively are causing it
Observed Simulated all factors - GHGs Simulated
all factors GHGs
6
(No Transcript)
7
2nd hottest on record
Hottest on record
8
(No Transcript)
9
What are the root causes of climate change?

• Population growth is not the key issue
• Growth in number and wealth of consumers
• Technological change and urbanisation
• Addiction to fossil fuel

10
Putting the blame on population growth is
blaming the wrong countries and the wrong
subgroups in those countries.
Sixty-three per cent of the worlds population
growth occurred in countries with very low
emissions
1980 to 2005 from Satterthwaite 2009
11
Not the population explosion!
growth in world population and CO2 19802005
(Satterthwaite 2009)
12
Area denotes total footprint, colour per capita
foot print
13
Wealth and urbanisation are important causally
small blue diamonds low-income nations small
white diamonds lower-middle income Large blue
trianglesupper-middle income nations large blue
squares high-income nations.
14
Wealth Explosion
Human Development Index vs. Ecological Footprint
HDI is normalized measure combining life
expectancy, literacy, educational attainment, and
GDP per capita . EF is area of Earth's productive
land and water required to supply all the
resources that an individual demands
15
Explosion in energy use our addiction to fossil
fuels and changing our environment
16
Environmental impact population x affluence x
technology (IPAT). Environmental impact
consumers x affluence x technology ( ICAT)
17
Temperature
Direct impacts Marine acidification, plant growth
reduced, destruction of limestone, kidney stones
Natural forcings Volcanic eruptions Ice and cloud
cover Ocean circulation changes
The rest of the presentation follows a logical
sequence from emissions to accumulation in the
atmo
(land use, land use change and
forestry ) Electricity and heating, Land
transport etc.
18
GHG emissions

• What? from where? and how fast?

19
2
Global Warming Potential is a measure of how
powerful a unit mass of a greenhouse is at
producing global warming
The CO2 e , (concentration of CO2 equivalent to
the warming effects of all the GHGs put
together ) is the sum of concentration x GWP for
each gas
20
(No Transcript)
21
Global emissions (GtC/y)
Raupach et al. PNAS June 12, 2007 vol. 104 no.
24 10289
22
(No Transcript)
23
Where do they come from?
Direct escape from coal mining, oil production,
refining gas wells etc
24
(No Transcript)
25
GHG atmospheric concentrations

• How are they increasing?

26
From emission rates to atmospheric concentrations
How fast the bath fills depends on the rate at
which water flows in (sources- the taps) and out
(sinks- the plug hole and overflow outlet)
27

• The rate at which CO2 is removed from the
  atmosphere depends on the rate of the sources
  and sinks

28
The fraction of CO2 remaining in the air, after
emission by fossil fuel burning, declines rapidly
at first, but 1/3 remains in the air after a
century and 1/5 after a millennium (Atmos. Chem.
Phys. 7, 2287-2312, 2007).
29
CO2 is a cumulative in the atmosphere
30
and its difficult to predict how well the
natural sinks will cope as CO2 levels rise in the
future but they are threatened by

• Warming , drying of forests and deforestation
• Changes in agricultural practice
• Marine acidification
• Higher sea temperatures

31
CO2 measurements from ice cores and recent
observations

• Concentration of CO2 much higher now than at any
  time in the last 800,000 years

32
so CO2 is a cumulative poison
1750 1800
1850 1900
1950 2000


33
Ice traps gas bubbles enabling us to measure
atmospheric concentrations in the past
The increase starts in about 1750
34
(No Transcript)
35
Its not just CO2 concentrations that are
increasing in the atmosphere
Source IPCC Working Group 1, Summary for
Policymakers (2007)
36
and greenhouse gases differ weight for weight
in their potential for causing global warming
37
From atmospheric concentrations to temperatures

• How hot will it get and how fast will this happen
  if we carry on as usual?

38
How hot will the planet get at a given
atmospheric CO2 level?

• Three factors determine eventual temperature rise
  
• gas concentrations
• warming potential of each gas
• and climate sensitivity
• The climate sensitivity the eventual
  temperature rise (equilibrium temperature)
  produced by a doubling in greenhouse gas
  concentration.
• There is uncertainty about the climate
  sensitivity. The IPCC assumes a range 2C -
  4.5C but does not rule out greater sensitivity.
  Hansen (Director of NASA planetary science lab)
  considers that a sensitivity of 6C is needed to
  include the effects of slow vicious cycles
  (positive feedbacks e.g. methane release from
  the permafrost and oceans).

39
How temperatures are predicted to rise for
different atmospheric concentration scenarios
UK met office prediction 28.09.09
Source IPCC Working Group 1, Summary for
Policymakers (2007)
40
(No Transcript)
41
Effects of greenhouse gas emissions will remain
with us for many centuries
Source IPCC (2001)
42
How much carbon in the form of CO2 can we emit
during the period 2000 to 2050?
43
(No Transcript)
44
The probability of exceeding 2oC for different
cumulative emissions budgets
Meinhausen 2009. Nature 458, 1158
45
1.0 1.44 trillion tonnes
of carbon
C02 target 2000 to 2050
1 in 4
1 in 2 probability of exceeding 2oC
0 0.5
1.0
1.5 2.0
2.5
Trillion tonnes C
Greenhouse-gas emission targets for limiting
global warming to 2oC Meinhausen et al. Nature
Vol 458, 30 April 2009 See also Allen et al in
the same issue.
46
Limiting the total quantity of CO2 emitted over
the period 200050 to 1,000 Gt gives odds of 1 to
3 (or 25 probability 1 chance in 4) that
warming will exceed 2 ?C. A limit of 1,440 Gt
CO2 gives evens ( 50 probability 1 chance in
2) that temperature will exceed 2 ?C. Over the
period 200006 CO2 As we have already emitted 234
Gt CO2, less than half the proven economically
recoverable oil, gas and coal reserves can still
be emitted up to 2050 to achieve such a goal.
Review of many recent models and scenarios By
Meinhausen et al. Nature Vol 45830 April
2009 See also Allen et al in the same issue.
47

• Since 2000 we have already emitted 0.244 trillion
  tonnes out of the 1 trillion budget..
• Thats 23 of the budget in 12 of the time

48
It is not too late yet but we may be very
close. The 500 billion tonnes of carbon that
humans have added to the atmosphere lie heavily
on the world, and the burden swells by at least 9
billion tonnes a year. If present trends
continue, humankind will have emitted a trillion
tonnes well before 2050, and this would be
enough to push the planet into the danger zone.
And there is no reason to think that the pressure
will stop then. The coal seams and tar sands of
the world hold enough carbon for humankind to
emit another trillion tonnes and apocalyptic
scenarios extend from there.
Editorial . Nature April 30th 2009
49
Postscript

• World GHG emissions must peak in the next few
  years and decline rapidly thereafter
• The UK needs to make year on year cuts of about
  8 p.a. to a 90 reduction on 2009 levels by
  2050.
• Climate change will become the largest threat to
  national security and wellbeing .
• Therefore the government must to take vigorous
  and immediate action on this threat.
• The world needs a fair, binding treaty at
  Copenhagen with targets dictated by the best
  Science rather than other needs.
• Change is needed at all levels to enable a smooth
  transition to a practically zero carbon world.
• Individual and corporate change must be coupled
  with effective political campaigning.

50

• Thank you for your attention

51
Impacts of different global mean temperatures
52
US National Snow and Ice Data Centre http//nsidc
.org/data/seaice_index/
53
Greenland Total Melt Area 2007 value exceeds
last maximum by 10
Konrad Steffen and Russell Huff, CIRES,
University of Colorado at Boulder
54
Surface Melt on Greenland
55
(No Transcript)
56
(No Transcript)
57
New study by the Met Office 28.09.09 indicates
that with BAU ,global mean temperatures could
increase 4C above pre-industrial levels by 2060.

• Arctic could warm by up to 15 C
• Western and southern Africa warming up to 10 C
  and drying.
• Some land areas could warm  gt7C .
• Rainfall could be 20 less or increase in some
  areas.
• All models indicate rainfall decrease over
  western and southern Africa, Central America, the
  Mediterranean
• Rainfall in India could increase by 20 with
  heightened risk of river flooding.
• Huge impact on food production

58
(No Transcript)
59
(No Transcript)
60
(No Transcript)
61
(No Transcript)
62
(No Transcript)
63
(No Transcript)
64
Climate change and international conflict

• 10s of millions displaced
• Hunger and famine
• Increased incidence of disease
• Increased incidence of severe weather

Climate Change, coupled with other stresses, can
lead to local and regional conflict and migration
depending on the social, economic and political
circumstances WBGU 2007
65
(No Transcript)
66
Mitigation Strategy

• Putting a price on carbon through
• Capping fossil fuels or
• Capping emissions
• Energy taxes
• Widening scope of Clean Development mechanism
• Regulation - national, regional and global
• Technology transformation
• Renewables
• Increased energy efficiency
• Low carbon transportation
• Carbon capture and storage
• Research on carbon negative geoengineering
• Protecting and enhancing carbon sinks.
• Protecting forest and afforestation
• Mobilising behaviour change
• Citizens
• Business

67
(No Transcript)