Climate change: What is happening and what does it mean? Andrew Watkinson LWEC Director Durham 02 March 2011

Observations

Historical climate change CO 2 T CH 4 Age (kY BP) Inferred temperature °C

Climate is changing LANDSEA Source: Met Office The temperature changes are similar on land and sea

Global temperature change Different 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 relative to 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 temperature The 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 Satellite altimetry IPCC 2007

Impacts: Changing sea ice Arctic sea ice extent (Sept min: millions km 2 )

Impacts: changing distributions Warm- temperate species Temperate species SAHFOS 2007/8 report Plankton species

A decrease in surface ocean pH by an average of 0.1 units since Observations of pH for the last 20 years show trends of decreasing pH at a rate of 0.02 pH units per decade. pH CO 2 levels ppm Ocean acidification CO 2 in atmosphere CO 2 in seawater pH

Source IPCC AR4 Number of significant observed changes Percentage of significant changes consistent with warming Physical Biological %90% Global Climate change impacts

Attributing change Understanding and attributing climate change Source: IPCC 2007

Greenhouse gases Time before 2005 Carbon dioxideMethane

The greenhouse effect

Sound science the scientific basis for climate change is well established …

Looking forward Uncertainty and risk

90% GCMs agree (-60)% increase in winter precipitation % decrease in summer precipitation Changes in precipitation

Increasing sea levels Sea level is likely to rise much more by 2100 than the often-cited range of cm from the IPCC AR4.

And in the UK? 10, 50 and 90% probability levels of changes to the average daily mean temperature (ºC) of the winter and summer by the 2080s, under the Medium emissions scenario.

Future temperatures A future scenario: European 2003 heatwave could be normal by 2040s, cool by 2060s

Source: Parry et al 2008 Projected impacts Water Food Health Ecosystems Coast Events

A comparison of IPCC (2001) projections with observations from the year 1990 CO 2 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 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 (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 Fuel Production, Extraction &Transport PowerstationTransmission Electricity Consumption Light Source: Kevin Anderson

Managing demand: behaviour Abatement offers a net economic benefit of ≈$36 per-tonne CO 2e 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 behaviour Traffic 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 g/km  ~8 year penetration of new cars … ~90% of vehicle-km 50% CO 2 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 year 2035: £1 billion per year Managing the risk Source: Evans et al 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 plans Linking 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