Climate change –

beyond IPCCAlan Rodger

Introduction Some examples of changeExtreme events

Predicting the futureSurprises

Hydrosphere Geosphere

Atmosphere

Cryosphere Biosphere

Anthropo-

sphere

EarthSun

Earth System

Astronomical

Hydrosphere Geosphere

Atmosphere

Cryosphere Biosphere

Anthropo-

sphere

EarthSun

Earth System

Astronomical

Science

Cultural

Technology

Political

Social

Economics

Well beingWaterFoodShelterFuelHealthSecurity

IPCC, 2007

The climate system

IPCC Fourth Assessment Report

Climate Change 2007

•

Atmospheric GHG concentrations far exceed levels of last 650,000y as a result of human emissions

•

Warming of the climate system is “Unequivocal”

•

Climate forcing primarily human (x10 solar)

•

Agreed by delegates of 113 nations

IPCC does not capture non linear effects well

0km 1,000km 2,000km

80S°

70S°

60S°

Dome C

Vostok

Dome F

TaylorDome

Byrd

DronningMaud Land

Siple Dome

Dome CDome CLaw Dome

BerknerIsland

European Project for Ice Coring in Antarctica (EPICA)Ice cores –

the gold standard climate change record?

EU/ESF project1996-2006 Drilling depth of 3.27km~890 000 years old

Ice core processing and analysis

Dome C Antarctica Ice Core

Now –

386 ppm

Luthi et al., Nature, 15 May 2008Siegenthaler et al., Science 2005 (EPICA gas consortium)

• Increase ~0.8°C over the last century

• 2007 was 8th

warmest year on record

• 12 of the 13 warmest years on record occurred since 1995

• 2001-2007 was 0.21°C warmer than 1991-2000

Global Temperature

data source: Climatic Research Unit

Temperatures 1951-2001

Precipitation 1961-2002

Blue: positive trend; Red: negative

China

18 more growing days in the Qinghai-

Tibetan Plateau500 hours fewer sunshine in North China Plain compared with 50 years ago

Surface Temperature Rise

Polar amplification

The Key Science Issues for Polar Regions

•

Greatest uncertainty in global sea level rise

•

World’s largest carbon sinks, and with the potential for surprise (methane/hydrates)

•

Critical role of polar ecosystems and biodiversity in the maintenance of the earth system

•

The major driver of global ocean system, and hence fundamental to predicting world’s weather

•

Understanding how the planet works –

the polar component

Antarctic Peninsula Glacier Responses

244 glaciers -

87% have retreated over last 50yCook et al., 2005

Peninsula 1993-2003

Flow rate of over 300 glaciers

12% increase in glacier speed

Sea level rise: 0.16 ±

0.06 mm /y

Pritchard and Vaughan, 2007

Ice-thickness change 1992-2003

Major dischargesPine Island, Thwaites and

Smith Glaciers

The West Antarctic Ice Sheet and sea level rise

Bed elevation in Greenland and Antarctica

-2000

+2000

0

Bamber & Vaughan, BEDMAP.

ICE

LITHOSPHERE

OCEAN

Grounded below sea level

West Antarctica –

last of the great marine ice sheets

After G Clarke

11 Mar 2008Dublin Lecture no. 6 18

� Greenland is melting!

11 Mar 2008 Dublin Lecture no. 6 19

Arctic sea ice Median Sept. Extent 09.09.2008 1979-2000

IMPACTS

Shorter trade routesEasier access to oil and gasOcean circulationEcosystems

1

2

34

5

68

7

1: Barentshavet2: Sørlige Karahavet og Vest-Sibir3: Nordlige Karahavet4: Laptevhavet5: Øst-Sibirhavet6: Chuchihavet7: Alaska North Slope8: Øst-Grønnland

Resten av verdenArktis

Verdens uoppdagede petroleumspotensiale

N. AfrikaKaspihavetMidt-Østen

1

2

34

5

68

7

1: Barentshavet2: Sørlige Karahavet og Vest-Sibir3: Nordlige Karahavet4: Laptevhavet5: Øst-Sibirhavet6: Chuchihavet7: Alaska North Slope8: Øst-Grønnland

Resten av verdenArktis

Verdens uoppdagede petroleumspotensiale

N. AfrikaKaspihavetMidt-Østen

1.

Barents Sea2.

Southern Kara Sea and Western Siberia

3.

Northern Kara Sea4.

Laptev Sea5.

East Siberian Sea6.

Chukchi Sea7.

Alaska North Slope8.

East Greenland

World’s Petroleum Potential

Arctic

Rest of

World

North Africa,

Middle East

Sea Level Rise -

Tide Gauge Observations

-100

-50

0

50

100

150

1880 1900 1920 1940 1960 1980 2000

ΔMSL

(mm

)

Year

Average Rate ~ 1.8 mm/year

0.8 mm/year

2.0 mm/year

3.2 mm/year

Source: Church and White, 2006Source: Church and White, 2006

Sea level trends between January 1993 and December 1999 from satellite data in mm/yearRed = sea level rise : Blue = sea level fall

Tuvalu 8°S, 179°E

•

Land area 26 square kilometres•

Population 4492•

Third least populated independent country•

Second smallest member of the UN•

Tuvalu has very poor land; soil is hardly usable•

Almost no reliable supply of drinking water

Sea level rise and the EU

Within 500 m of the coast

•

14% of population (70 m people)

•

economic assets located of the EU's coastline valued of €1,000B

•

47,500 km2

of sites of high ecological value

15 countries have substantial coasts that are open to the world’s oceans

•

coastal flooding,

•

increased rates of erosion

•

destruction of natural sea defences

•

threats to human lives and livelihoods

Annual expense of protection €3.2 billion and rising non-

linearly

Managed retreat only option in some areas

.

Extreme events

Ciais et al., Nature 2005

effect of the 2003 heat wave in Europe

Hurricane frequency not changing

Katrina from space

HannaIke

Josephine

Gustav

Karina

3 September 2008

Webster, et al., Science 2005

Hurricane intensity is increasing

Number of hurricanes unchanged

Katrina from space

60% of rice from Irrawaddy Delta

Mangroves swamps cleared for crops -

protection lost

Crops destroyed by storm surge

The saltiest areas will have to be drained and flushed with fresh water before they can be re-planted

Draining a challenge as designed to hold water

Cyclone Nargis hits Burma May 2008

Heavier precipitation, more intense and longer droughts….

Drought areas already expanding and predicted to expand further

1960 1980 2000 2020 2040 2060 2080 2100

Perc

enta

ge in

dro

ught

50

40

30

20

10

0

Percentage of world's land area in drought

Source: Burke, EJ and SJ Brown. Modelling the recent evolution of global drought andprojections for the 21st century. Journal of Hydrometeorology, 2006

Vulnerable

LowModerateHighVery high

Desertification

IPCC Temperature Projections

Uncertainties in prediction

1.

Future emissions are not known2.

Computer models are not perfect

3.

Natural variability of climate occurs

Therefore

Improve understanding and modelling of the climate system

Quantify uncertainty: probabilistic forecasts

Incorporate probabilistic forecasts into decision making tools

geological reservoirs

fossil fuel emissions land use

changeland sink

ocean sink

7.2 1.5 2.3

2.2

atmosphere4.2

The carbon cycle2000-2005 CO2

budget (GtC/y)

Canadell et al. 2007

Natural and man-made sources and sinks changing

Raupach et al., 2007

fossil fuel CO2

emissions for the world

CO2

emissions increase 1990s

1.3% y-1

2000-2006 3.3% y-1

CO2

growth rate65±16% from increasing global economic activity17±6% from the increasing carbon intensity of the global economy18±15% from the increase in airborne fraction

Canadell et at., PNAS, 2007

Less carbon draw down from the atmosphere into the oceans

Cause: Increase in

Southern Ocean winds

Le Quéré

et al., Science, 2007

The other carbon problem 1-

ocean acidification

800 ppm

CO2

is corrosive to the shells of many marine organisms

Phytoplankton assemblages will change

The other carbon problem 2 -

methane

800 ppm

More carbon locked up in methane than in oil and gas

Methane from the tundra

Methane from the ocean

Methane from farming

Surface area 17,160 km²

(2004, three lakes)

28,687 km²

(1998, two lakes)

68,000 km²

(1960, one lake)

Fivefold increase in salinity

Weapons testing

Wind blown salt damages crops

Polluted drinking water

Salt and dust laden air causing health problems

“The Aral Sea, the worst man-made environmental disaster”

says UN

Aral Sea

1989 2003 Water

Water

Change of rainfall in 2090 compared with 1990

Lack of melting snow Changes in precipitation –

very hard to predict

•

The Earth system is highly coupled

•

Change occurring everywhereRates of change increasingFastest at the polesRate of change unprecedentedHumans are affecting the planet

•

IPCC -

conservative•

Predicting the future: the big challenge

•

BUT challenge the climate scientist

Conclusions

Probabilistic forecasts

geoengineering

options

Keith, Nature, 2001 Problems:• difficult to scale up• difficult to prove efficiency• difficult to reverse• possible side-effects• decades of research needed

Model Improvements

The economics of ecosystems and biodiversityEuropean Commission, 2008

The glacial cycle

Temperature rises a little because of the orbit of the Earth

Warmer waters cannot dissolve as much CO2

Increase in temperatureIncrease CO2

leads to more heating

Other feedbacksincrease phytoplankton at high latitudesless sea ice

Earth‘s OrbitEarthEarth‘‘s Orbits Orbit

Milankovitch cycles

Temperature precedes CO2

Variations/uncertainties

Long term –

cryosphere years/decades -

m

Storm surges –

pressure/winds 1–5 days -

up to 5 m

Ocean surface topography (changes in water density and currents) -

days to weeks -

up to 1 m

El Niño-Southern Oscillation (ENSO) -

up to 0.6 m

River runoff/floods -

2 months -

1 m

Seasonal water density changes (temperature/ salinity) -

6 months 0.2 m

Sea-Level Rise Could Wipe Out Bangladesh by 2100Proudman Oceanography Laboratory, 2008X 4 IPCC estimates of sea level rise

Serengeti2005 2006January

South Sandwich Trench 6348 m © Diaz & Carpenter, VIMS

Unexpected high diversity in the Southern Ocean deep sea: > 1400 species, > 700 new, undescribed species

Isothermal environment Southern Ocean warmingAnimals susceptible to change

Impacts of change on the Antarctic Peninsula

Natural Variability

Variability on long term trends

Long term and abrupt climate change

Methane hydrates

Methane from tundra

The Intergovernmental Panel on Climate Change (IPCC) has been established by WMO and UNEP to assess scientific, technical and socio-economic information relevant for the understanding of climate change, its potential impacts and options for adaptation and mitigation.

11 Mar 2008 Dublin Lecture no. 6 60

Projected patterns of precipitation changes 2090/2099 : 1980/1999

Dec-Feb Jun-Aug

Stippled areas: uncertain40% of the world’s food supply requires irrigation

Socolow

Zachos

et al. 2008

385

180

1850

2008

650 thousand years

atmospheric CO2

(ppm)

280

1958

Siegenthaler et al. 2006

Atmospheric increase = Emissions from

fossil fuels + Net emissions from changes in land use - Oceanic

uptake - Missing carbon sink

3.2 (±0.2) = 6.3 (±0.4) + 2.2 (±0.8) - 2.4 (±0.7) - 2.9 (±1.1)

Plantations in Campo-Maan

in Cameroon now dominate the landscape (right)30 years ago the forest appears largely intact

Declining water levels in Lake Chad. Persistent droughts and increased agricultural irrigation have reduced the Lake’s extent in the past 35 years to one tenth of its former state

The drying up of Lake Faguibine

in Mali. When the lake was full (left) it was amongst the largest lakes in Africa but in the 1990s it dried up completely (right)

The disappearing Damietta

Promontory in Egypt. The promontory has eroded dramatically in the last 30 years as waves and currents have stripped its sands faster than the river can replenish them

Antarctic ice shelf 'hanging by a thread'

Vast iceberg breaks off Wilkins Ice Shelf in Antarctic

28 Feb 2008

17 March 2008

Vaughan et al., 2008

Ecosystems

Ecosystem services are the benefits that people obtain from ecosystems

Examples include food, freshwater, timber, climate regulation, protection from natural hazards, erosion control, pharmaceutical ingredients, clean air recreation etc.

Since 1900 50% of the world’s wetlands have been lost

30% of coral reefs have been seriously damaged through fishing, pollution, disease and coral bleaching

In the past two decades 35% of mangroves have disappeared

Rates of species extinction are 1000 times more rapid than the natural rate

The economics of ecosystems and biodiversityEuropean Commission, 2008

Southern Ocean Ecosystem

Ocean ecosystems

High productivity in the Southern Ocean

Least exploited fishery

The unknown

The deep sea

Lakes and river systems under the ice

Woods Hole Research Centre, 2007

The carbon cycle

King et al, in prep.

Hudson Mountain Subglacial

Volcano

Estimated date of eruption - 220 BC

Rahmstorf

et al. 2007

Is the IPCC Conservative?

Comparison of reality with IPCC 2001 predictions

BAS Mission

•

to undertake a world-class programme of science

•

to sustain for the UK an active and influential regional presence, and a leadership role in Antarctic affairs

Broader Context

60 yr historyApprox 500 staff

Annual budget approx £40 MScience Logistics

Stations

BAS in Summary

The greenhouse effect –

a misnomer?

Transmission of visible light and infrared radiation the same

Greenhouses work by lack of convection

The ‘greenhouse’

effect has been understood for nearly 200 years

The ‘natural’

CO2

keeps the Earth around 30°C warmer than it would otherwise be

Survey by BAS and University of Texas, 2005

Pine Island Season 2006-07

Ice accessible for discharge ~1.5m msl

equivalent

20052004 2006

2007

Harlequin Ladybird

Impacts of climate change and mankind

Wandering albatross-

1% decline p.a. (pre-1997)-

4% decline p.a. (post-1997) 19

60

1964

1972

1976

1980

1984

1988

1992

1996

2000

2004

2008

8 0 0

1 2 0 0

1 6 0 0

2 0 0 0

80% reduction of krill in 30 years –

key food for birds, seals and whales

By catch

Ecology

Evolution

Physiology and molecular processes

Precipitation changes Frost changes

Gentoo penguin breeding success at Bird Island

Year1985 1990 1995 2000

Bre

edin

g S

ucce

ss a

t Bird

Isla

nd

0.0

0.2

0.4

0.6

0.8

1.0Years of extremely low performance

Long term trend 1976-2004

The interconnected world

Southern Ocean Ecosystem

•

Clear link between warm conditions and breeding failure in penguins, seals and whales

•

Long-term decline in krill abundance

•

New interest in krill fishing - aquaculture, pharma

and

neutraceuticals

•

The largest under-exploited protein resource -

managing sustainable

fishing critical

Lake Faguibine, Mali

1974 2005

590 km 2 in 1974Red= vegetation

traditional livelihoods of fishing, agriculture, and livestock herding became impractical

Lenton, T. M. et al. (2008) Proc. Natl. Acad. Sci. USA 105, 1786-1793

Tipping points

Subsystems indicated could exhibit threshold-type behaviour in response to anthropogenic climate forcing, where a small perturbation at a critical point qualitatively alters the future fate of the system.

Tipping points

Fisheries

•

Over exploitation

•

Global problem

•

Ecosystem change

•

By-catch

Convention on the Conservation of Antarctic Marine Living Resources

In 2002 fish provided more than 2.6 billion people with at least

20

percent of their average per capita animal protein intake

CO2

emis

sion

s (G

tC/y

)World

N. America

W. EU

China

Indiadata source: CDIAC and EIA

CO2

emissions increase 1990s

1.3% y-1

2000-2006 3.3% y-1

CO2

growth rate65±16% from increasing global economic activity17±6% from the increasing carbon intensity of the global economy18±15% from the increase in airborne fraction

Canadell

et at., PNAS, 2007

Carbon dioxide increases