www.lwec.org.uk

Climate change:What is happening and what does it mean?

Andrew WatkinsonLWEC Director

Durham 02 March 2011

Observations

Historical climate change

CO2

T

CH4

Age (kY BP)

0 100 200 300 400

Inferredtemperature

°C

Climate is changing

LAND SEA

Source: Met Office

The temperature changes are similar on land and sea

Global temperature changeDifferent data sets produce similar results

Source NASA

Rates of temperature change

Source IPCC AR4 WG1

Rates of change depend on the time period

Has global warming stopped?

Global temperature according to NASA GISS data since 1980

Regional warming

Mean surface temperature change (°C) for 2001-2007 relative to 1951-1980

Trend in ocean surface temperature (°C) from 1959 to 2008

And in the UK?

The Central England Temperature has risen by about one degree since 1980, a more rapid rise

than that of global mean temperatureThe change in temperature

between 1961 and 2006

And in 2010?

Source: NOAA

• From 1961 to 2003 the average rate of global sea level rise was 1.8 ± 0.5 mm yr–1

• From 1993 to 2003, the rate of sea level rise is estimated from observations with satellite altimetry as 3.1 ± 0.7 mm yr–1

• It is not clear whether the recent trend reflects decadal variability or an increase in the longer term trend

Impacts: changing sea level

Tide gauge measurements

Satellitealtimetry

IPCC 2007

Impacts: Changing sea iceArctic sea ice extent

(Sept min: millions km2)

Impacts: changing distributionsWarm-

temperate species

Temperate species

SAHFOS 2007/8 report

Plankton species

• A decrease in surface ocean pH by an average of 0.1 units since 1750.

• Observations of pH for the last 20 years show trends of decreasing pH at a rate of 0.02 pH units per decade.

pH

CO2 levelsppm

Ocean acidification

CO2 in atmosphere

CO2 in seawater

pH

Source IPCC AR4

Number of significant observed changes

Number of significant observed changes

Percentage of significant changes consistent with

warming

Percentage of significant changes consistent with

warming

Physical Biological

765 28671

94% 90%

Global

Climate change impacts

Attributing changeUnderstanding and attributing climate change

Source: IPCC 2007

Greenhouse gases

10000 5000 0 10000 5000 0

Time before 2005

Carbon dioxide Methane

The greenhouse effect

Sound sciencethe scientific basis for climate change is well established …

Looking forward

Uncertainty and risk

90% GCMs agree

• 0 - 30 (-60)% increase in winter precipitation• 0 - 40% decrease in summer precipitation

Changes in precipitation

Increasing sea levels

Sea level is likely to rise much more by 2100 than the often-citedrange of 18-59 cm from the IPCC AR4.

And in the UK?

10, 50 and 90% probabilitylevels of changes to the

average daily mean temperature (ºC) of the

winter and summer by the 2080s, under the Medium

emissions scenario.

Future temperaturesA future scenario: European 2003 heatwave

could be normal by 2040s, cool by 2060s

Source: Parry et al 2008

Projected impactsWater

Food

Health

Ecosystems

Coast

Events

• A comparison of IPCC (2001) projections with observations from the year 1990

• CO2 observations follow the projections almost exactly

• Temperature is in the upper part of the projected range

• Observed sea level has been rising faster than the model projections

• IPCC have not exaggerated change and in some respects may have underestimated the change

Rahmstorf et al. 2007 Science

Are we exaggerating the change?

Do we agree?

97-98% of the climate researchers most actively publishing in the field support the tenets of anthropogenic climate change outlined by the IPCC

What is the debate about?

• Climate gate• IPCC (glaciers)• Mild winters

What should we do?

Action: reducing emissions

Examples of global emission pathways where cumulative CO2 emissions equal 750 Gt during the time period 2010-2050 (1 Gt C = 3.67 Gt CO2). At this level, there is a 67% probability of limiting global warming to a maximum of 2°C.

• Energy (61.3%)• Land use (18.2%)• Industrial processes (3.4%)• Agriculture (13.5%)• Waste (3.6%)

Source

Targeting demand

FuelProduction,Extraction &TransportPowerstationTransmission

ElectricityConsumptionLight

10 50 54 120 133

Source: Kevin Anderson

Managing demand: behaviour

• Abatement offers a net economic benefit of ≈$36 per-tonne CO2e in 2030

• Achieving meaningful reductions in passenger vehicle emissions will be challenging

large upfront investment needed substantial barriers to changing consumer behaviour need for timely action

Driving behaviourTraffic flow

Total distance

McKinsey and Co. 2009

(without rebound)

UK mean car emissions ~180g/km (new ~155g/km)

EU 2015 plan 130g/km

Current performance 2010 BMW 3 series 160BHP diesel 109g/km 2010 VW, SKODA etc 85-99g/km 2010 Audi A3 3 Sportback ~ 109g/km 2010 Toyota Prius 1.8 89 g/km

~8 year penetration of new cars … ~90% of vehicle-km

50% CO2 reduction by 2020 with no new technology

Add reversed trend in occupancy ~ 70% by 2020

Efficiency and regulation

The Consensus Product Roadmap, mutually agreed by OEMs, defines future direction to develop products that will benefit UK plc

Technical innovation

TSB Low Carbon Vehicles IP

• 72 projects

• 200 partners

• £100 m grants generating £250 m project value

Difficult choices

Transforming the energy supply

SEI 2009

Geoengineering options

Aerosols in stratosphere

Iron fertilisation in

sea

Pump liquid CO2 into deep sea

Pump liquid CO2 into

rock

Greening deserts

GM crops

Grow trees

Cloud seeding

Chemicals to save ozone

Giant reflectors in orbit

IGBP 2009

Adaptation

Ranger et al 2009

Robust adaptation

2005: £575m per year2035: £1 billion per year

Managing the risk

Source: Evans et al. 2004

Foresight flood risk

But ..... Flooding from intense rainfall events

Responding to change

Source: Emma Tompkins

Governance lies at the heart of our response

National frameworks and localism

Leadership and

responsibility

Risk management

plansLinking and

co-ordination of planning processes

Legislation, regulation and enforcement

Support networks

Finance

Information and good science

Education and knowledge exchange

Meeting the challenge of

environmental change

Summary• Is our current climate changing?• What is causing climate to change?•What should local and global environmental and climate change priorities be?• What is the strength of the consensus of man-made climate change compared with natural climate change?• How to interpret scientific uncertainty?• The scientific nature of the issue versus the need to get all people engaged• What is the role of local government is, given their responsibilities for the well being of their residents and businesses?• Should the focus be on adaptation or mitigation?• If we grasp the issue there are considerable opportunities for both business and society

Yes

Anthropogenic greenhouse gases

Mitigation and adaptation

Very strong

Risk management framework

Both

8 functions

Scientific message clear. Local action within national framework

Aims to ensure that decision makers in government, business and society have the knowledge, foresight and tools to mitigate,

adapt to and benefit from environmental change

The LWEC partnership