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