THE SCIENCE
the
science
emissions rise
Emissions of CO2 from fossil-fuel bu
rapid rise since 1950
Variations of the Earth’s
temp risetemperature for the
surface
past 1,000 years
The last 160,000
ice cores
years
(from ice
cores) and the
next 100 years
Projected changes in annual temperatures for th
projected temp rise
IPCC 2007- Probable temperature rise between 1.8oC and
The MetOffice. Hadley Center for
4oC by 2100. Possible temperature rise between 1.1oC and
Climate Prediction and Research.
6.4oC.
Natural factors cannot explain recen
not volcanoes or sun spots
The MetOffice. Hadley Center for Climate Prediction and Research.
Recent warming can be simulated
when
man-made
factors are included
human emissions
The MetOffice. Hadley Center for Climate Prediction and Research.
Projected Patterns of Precipitation
precipitation changes
Precipitation increases very likely
in high latitudes
Precipitation decreases likely in
most subtropical land regions
From Summary for Policymakers, IPCC WG1 Fourth Assessment Report
Arctic summer sea-ice could disappear by
arctic ice
Arctic summer sea-ice could disappear by
Arctic ice
Deforestat
ion
Deforestation
S. Bahia
(Brazil)
1945
Deforestat
ion
Deforestation
S. Bahia
(Brazil)
1990
Competition for land
Competition for Land
Croplands & pasture-lands now cover c.40% of world land
area
Cities, roads, & airports now cover 2% of world land.
The geography of water
Water Stress
stress
Changing disaster patterns:
 weather related disasters doubled over the past 2 decades
 increase small- and medium-scale disasters
 more uncertainties
Disaster trends
400
300
200
100
0
‘9 ‘91 ‘9 ‘93
0 geo- 2
physical
‘9 ‘95 ‘96
4
epidemics,
‘9 ‘98
7
insect infestations
‘9 ‘00 ‘0 ‘02
9hydro- 1
meteorological
‘0 ‘04
3
‘0 ‘06
5
Source:
CRED
Increased species extinctions
Extinctions
Rising Sea Levels
Sea level rise
• sea level rise will bring
large coastal areas at risk
• salt water intrusion
threatens water supply and
food security
• impacts already being felt
particularly during storm
surge
Climate change projections have changed
dramatically recently
• Arctic summer sea ice reached record
minimum levels in 2005, 2007 and 2008,
80 years before CC models predicted it
• Jim Hansen re-modelled max viable CO2
level compatible with human civilisation
as 350ppm.
• We’re already at 384ppm.
• Current campaigns are for between 450ppm - 550ppm
Climate change projections have changed
dramatically recently
• Rajendra Pachauri, IPCC Chair stated Sept 08:
“the very latest science demonstrates that we need a fundamental
change in our carbon habits by 2012, or the earth’s carbon
feedback loops will be out of control.”
• He also stated: “the latest science now says a 2m sea level rise
will happen this century unless there is an early major reduction in
our emissions.”
• International Scientific Survey of
the Arctic sea in August 2008
reported a “boiling ocean”:
hundreds of thousands of funnels
of methane bursting out of the
sea. These are coming from
cracks in the previously frozen
sea bed, due to average arctic
temperature increase of 4oC
Climate change projections have changed
dramatically recently
• UK Met Office’s Hadley Centre warn that cutting global emissions
by 3% a year from 2010 offers the only possible hope of avoiding
a global temperature rise of more than 2oC
• Tyndall Centre reviewed CC models, incorporating rising global
emissions since 2000, and carbon feedback. Conclude that
unless dramatic reductions in GHGs take place urgently, we are
committed to a catastrophic 4oC rise
• This will leave most of Africa uninhabitable and much of the
Indian sub-continent incapable of growing crops, leading to
multiple global conflicts and displacement of billions of people.
Climate change projections have changed
dramatically recently
• Climate scientists are urgently re-modelling CC tipping points &
carbon feedback loops, fearing that they may happen much
earlier.
• Tipping points include the rapid melting of glaciers; sudden
collapse of the Greenland & West Antarctic ice sheets; collapse of
the Gulf Stream & El Niño; reversal of the Indian & West African
monsoons; rapid desertification of the Amazon and Siberian &
Canadian forests
• Carbon feedback includes the rapid release of methane and
carbon dioxide from permafrost, frozen sea beds, soil, forests and
the oceans
• Sir Nicholas Stern, Oct 2008: “The only way out of the current
global financial crisis is to bring low carbon technologies to the
top of the agenda.”
UK Met Office: world
heading for 5-7oC rise
“Business as usual” means:
• mass extinction
• devastating ocean acidification
• brutal heat waves
• sea level rise 1 to 2m by 2100
• >100 million env refugees
• >1/3 planet desertified
• ½ the planet in drought
• loss of all glaciers providing water
to a billion people