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Climate Change – an Emerging Issue in Health
Colin SummerhayesScientific Committee on Antarctic Research (International Council for Science)
Scott Polar Research Institute, Cambridge University
Ex Member: Steering Committee for the Global Climate Observing SystemEx Director: Institute of Oceanographic Sciences Deacon Laboratory, UK
World Health Organisation’s Global Health Histories Seminar, Geneva, 24 March 2010
Climate change and health
IPCC WG‐II, 2007
Aside from extreme events, climate change is seldom the main factor in considering stresses on sustainability;
Vulnerability depends onspecific geographical and social contexts (state ofdevelopment is a key);
Adaptive capacity needsto be improved (fresh water and sanitation infrastructure);
Adverse impacts will be higher in poorer countries;
Access to water is a key vulnerability indicator (the Issue of aquifers).
Malaria: additional 220-400 million at risk; Reduction in SE Africa in 2020; decreases in Sahel and south-central Africa in 2080; local increases in highlands by 2100. Some increased risk in UK, Australia, India and Portugal.
Climate science: the fundamentals
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Climate science: the fundamentals
Greenhouse gases warm the planet
• 1827
– Jean‐Baptiste
Fourier
first
recognises
warming
effect
of
greenhouse gases
• 1860
– John Tyndall first measures the
absorption
of
infrared
radiation
by
carbon dioxide and water vapour
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Climate science: the fundamentals• 1769 James Watt patents his steam
engine, marking onset of the Industrial Revolution
• 1957 – Keeling starts to measure atmospheric CO2 concentration in Hawaii
• 2000s – Isotope analysis shows CO2 in the air carries the signature of fossil fuels
IPCC 2007 has “very high confidence”that humans are increasing the concentration of greenhouse gases, so making temperatures rise –
10% probability that this is NOT the case.5
Carbon dioxide concentration over the past 1000 years
David MacKay‘Sustainable energyWithout the Hot air’
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http://www.census.gov/main/www/popclock.html
GLOBAL POPULATION ESTIMATES
A vicious circle for our times
More people use more energy;More energy means more emissions;More people want affluence;More affluence means more gadgets;More gadgets need yet more energy;Which produces yet more emissions.
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The consequences
• The world is getting
hotter (very slowly
0.1°C per decade)
• Sea levels are rising
(very slowly 3mm/yr)
• Snow cover is
decreasing
IPCC, WG1, Figure SPM.3, 200710
The Ups and Downs of El Niño & La Niña
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Global monthly and 12-month running mean surface temperature anomalies relativeto 1951-1980 base period, and the Nino 3.4 index. Data extend through February 2010
J Hansen, NASA-GISS, 2010
The last 10 years are all in the top 15 warmest years on record
12Global Ranked HADCRUT3, UK Met. Off.
Weather
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If you thought the winter of 2009-10 was cold it’s because you live in western Europe or the USA. Baffin Island was 7°C warmer than usual. Remember the
Winter Olympics – not enough snow in Vancouver. You were experiencing weather, not climate.
Atmospheric water vapour has increased (the atmosphere can hold more water when the air
temperature is higher)
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Warming causes evaporation;Water is a greenhouse gas;More water vapour provides positivefeedback to thewarming causedby CO2 .
Arctic sea ice coverage is decreasing
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Less sea ice means less reflectionof the sun’s energy;More exposure of dark coloured oceanmeans more absorption of the sun’s heat;These combined effects warm the Arctic, helping to melt more sea ice – another vicious circle(otherwise known as positive feedback).
Rates of ice loss are increasing
16P Barrett, 2010 Kaser et al., 2006
Understanding climate in 1975Early modelling of temperature response to changes in CO2
Manabe and Wetherald, Journal of Atmospheric Science,1975
Stratospheric cooling
Troposphericwarming
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Poles warm more than anywhere else
What would human induced warming look like? Observed temperature trends 1979‐2004
Stratospheric cooling
Troposphericwarming
IPCC 2007,WG1, AR4, Figure 3.1818
Stratosphere
How do we know it’s human induced?Amplitude of solar and human influence
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Bard & Delaygue, 2008
Why does this matter? How could warming increase in future?
IPCC, WG1, 2007, SPM‐520
Change and uncertainty in projected temperatures relative to 1980‐99
IPCC WG‐1, 2007
uncertainties
B1 = low carbon economy; population peak at 2050;A1B = rapid growth economy; balanced energy sources; population peak at 2050;A2 = slower development; population peak at 2100.
More people die when it’s cold
22BMJ 2001;323:1207 ( 24 November )
United Kingdom has an estimated 50,000 excess deaths in winter
IPCC WG‐1, 2007
Key Impacts ‐WaterGlobal mean annual temperature change relative to 1980-1999 (C)
0 1 2 3 4 5 C
Increased water availability in moist tropics and high latitudes
Decreasing water availability and increasing drought in mid-latitudes and semi-arid low latitudes
Hundreds of millions of people exposed to increased water stress
mi-arid low latitudes
Mongolian drought turns Beijing orange
25Independent 22 March 2010
Winners and Losers
Relative to 1980‐99IPCC WG‐1, 2007
Key Impacts ‐ EcosystemsGlobal mean annual temperature change relative to 1980-1999 (C)
0 1 2 3 4 5 C
Up to 30% of species at Significant extinctionsincreasing risk of extinction around the globe
Increased coral bleaching Most corals bleached Widespread coral mortality
Terrestrial biosphere tends toward a net carbon source
Increasing species range shifts and wildfire risk
Ecosystem changes due to weakening of themeridional overturning circulation
Increasing species range shifts and wildfire risk
Ecosystem changes due meridional overturning circulationEcosystem changes due to weakening of themeridional overturning circulation
to weakening of theEcosystem changes due meridional overturning circulation
Up to 30% of species at Significant extinctions
g Most corals Widespread coral mortality
The other big carbon dioxide problem – ocean acidification
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Key Impacts ‐ FoodGlobal mean annual temperature change relative to 1980-1999 (C)
0 1 2 3 4 5 C
Complex, localised negative impacts on small holders, subsistence farmers and fishers
Tendencies for cereal productivity Productivity of all cerealsto decrease in low latitudes decreases in low latitudes
Tendencies for some cereal productivity Cereal productivity toto increase at mid-to-high latitudes decrease in some regions
istence farmers and fishers
decreases in low latitudesproductivity
ctivity Cereal productivity toto increase at mid-to-high lati some regionsto increase at mid-to-high latito increase at mid-to-high lati
ZIMBABWE MAIZE YEILD AND EL NIZIMBABWE MAIZE YEILD AND EL NIÑÑOO
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Key Impacts ‐ CoastsGlobal mean annual temperature change relative to 1980-1999 (C)
0 1 2 3 4 5 C
Increased damage from floods and storms
About 30% ofglobal coastalwetlands lost
Millions more people could experiencecoastal flooding each yearcoastal flooding each yearcoastal flooding each yearcoastal flooding each year
Projected change in sea level to 2100
Church et al., 2008
1.4 m max projection from Rahmstorf model (2007); = Daily rise (1.5cm/yr) only visible with time-lapse photography; i.e. Not a tsunami. A creeping catastrophe.
146 million people live within 1m of sea level;1.4m rise will have significant effect on coastal megacities
and offshore platforms;Need coastal engineering solutions.
IPCC original
IPCC add-on
Current rate = 3.4mm/yr
Melting Antarctic ice – rising global seas: ‐how will coastal megacities cope?
1 metre sea level riseNW Europe
Redesign Barrier to withstand 2m rise
London – estimated bill for one flood: £30bn = 2% of GDP
Key Impacts ‐ HealthGlobal mean annual temperature change relative to 1980-1999 (C)
0 1 2 3 4 5 C
Increasing burden from malnutrition, diarrhoeal, cardio-respiratory, and infectious diseases
Increased morbidity and mortality from heat waves, floods, and droughts
Changed distribution of some disease vectors
Substantial burden on health services
EL NIEL NIÑÑO AND HEALTH RISKS: MALARIAO AND HEALTH RISKS: MALARIA
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“The biggest impacts of global warming will be from the shifts in the frequency and duration of extreme events,
not the slow rise in the average temperature”
Chart: New York Times
Looks bad but needs adjusting for population growth and coastal growth
The Tragedy of the Commons
• Nobody owns the resource (the air we breathe);• More and more people want to use it (as a dump
for CO2
emissions);
• The value declines (as in overgrazing; overfishing; global warming);
• Classic market failure (markets are the problem not the solution);
• Polluters are not paying;• Regulation is the solution (Ozone and Whales).
37J. Stiglitz, “Making Globalization Work”
The climate problem is also an energy problem; the cost of energy is going up;
this will hurt developing countries and so affect health
Past peak oil pushes energy costs upfor finding new deep water oil
We are at or past or fast approaching peak oil
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450ppm CO2 equiv= 2°C
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Geoegineering –forming oceanic clouds to reflect solar energy
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Climate change and health
IPCC WG‐II, 2007
Recognise the rise inwarming is slow overnext 30 years.
Not facing health
tsunami;
A creeping catastrophe;
Plan for prevention – it’sbetter than cure.
Encourage improveddevelopment;
Clean water;
Good sanitation;
Low carbon economies.
Thank you for your attention!
Supplementary slides
Climate Science, International and Impacts team, CESA
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How do we know it’s human induced? Modelled warming compared to observed
Tett et al JGR2002 46
+
+
Natural Forcings only(volcanic,Solar)
GHG
Aerosols, ozone
Observations
Why does this matter?Impacts in a 4°C world
Change in temperature from pre‐industrial climate 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
Current City population • 3‐10 million • 10‐20 million
Meltingice
OceanAcidification
Rainforestloss
Reduced crops
Forestfire
Increased drought
Stronger tropical storms
Methane release
More heatwaves
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Climate in North Patagonian Andes
Newman et al., 2009
Summer (Nov-Mar) w.r.to 1908-2003 av.
Summer (Dec-May) w.r.to 1943-1999 av.
Tree ring and instrument data
1.0 = 2292 metres for Frias Glacier
How do we know it’s human induced? Relative contributions of natural and anthropogenic forcing
Solar Volcanoes
Greenhousegases
Ozone changes
Sulphateaerosols
Total
IPCC 2007 WG1 Fig 9.149
The last 10 years are all in the top 15 warmest years on record
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Why does this matter?Negative impacts increase with temperature
IPCC, 2007 WG251