1. Indicators of Climate Change in the UK Melvin G R Cannell

2. OECD Pressure – State – Response Concept Pressure State Response Human activities Stocks and quality of resources Management or policies Industrial activity Greenhouse gas concentrations Climate Change Hydrology and sea level Plant, animal and human behavioural responses Policy responses Pressure State Pressure Response State Pressure State/Response State Response State/Response Response

3. Indicators of Climate Change in the UK 34 Indicators Climate, hydrology, sea level and air pollution (11) Temperature. Precipitation. NAO. River flows. Groundwater. Sea level. Thames barrage. Ozone. Insurance, energy, tourism and fire (5) Property claims. Gas use. Tourist trips. Skiing. Fires. Health (2) Lyme disease. Seasonal mortality. Agriculture and Forestry (8) Irrigation. Potato yield. Grapes and maize. Summer grass. Leaf emergence. Tree health. Insects and Birds (5) Insect activity. Swallow arrival. Bird egg-laying and abundance. Marine and Freshwaters (3) Marine plankton. Salmon behaviour. Lake ice.

4. Indicators of Climate Change in the UK Criteria for selection of variables 1.State variables (climate, sea level, hydrology) as well as response variables (plants, animals, sector behaviour). 2.Response variables known to be sensitive to climate. 3.Should have long historic time series to - establish climate sensitivity - provide baseline 4.Quality records available at low cost into the future. 5.Readily understandable to the public.

5. Indicators of Climate Change in the UK Cautionary points – the reality No assumption that climate trends and responses to climate are driven by increasing greenhouse gas concentrations. Few things change in response to climate alone. There are pitfalls in interpreting trends. Final selection determined very much by the data available, so impossible to cover some important responses to climate or give a balanced picture. The UK list preliminary, and aims only to detect change and alert public interest. Website: www.nbu.ac.uk/iccuk/

6. Indicators of Climate Change in the UK Trend over time Sea level Thames barrier closures Subsidence claims Outdoor fires Lyme disease cases Use of irrigation water Date of tree leafing Arrival of swallow Egg-laying dates of birds No obvious time trend Skiing in Scotland Groundwater levels in chalk

7. Indicators of Climate Change in the UK Hot, dry summers More domestic tourism More rural ozone More Lyme disease More irrigation Less healthy beech More insects Late migration of salmon Mild winters/springs Poor skiing Lower winter mortality Early tree leafing Early insect appearance Early breeding of birds

8. Indicators of Climate Change in the UK Seasonality Proportion of gas use in winter Seasonal human mortality Tree leaf emergence Insect appearance Arrival of swallow Egg-laying date of birds Migration of salmon upstream Change not wholly justified by climate - perception? Other factors? Area of vineyards Area of forage maize Irrigated potato area

9. Air temperature in central England No. days >20°C No. days <0°C

10. Precipitation gradient across the UK Scotland, winter SE England, summer

11. Predominance of westerly weather in winter

12. Risk of tidal flooding in London Thames Barrier closures per year

13. Scottish skiing industry

14. Domestic holiday tourism

15. Incidence of Lyme disease in humans

16. Warm-weather crops: forage maize grapes

17. Use of irrigation water for agriculture (England & Wales)

18. Proportion of potato crop that is irrigated (England and Wales)

19. Arrival date of the swallow

20. Insect abundance

21. Egg-laying dates of birds

22. Other Indicators suggested during UK consultation Climate and oceanSocio-economic Air temperature in more regionsAir conditioner sales Air temperature in the uplands‘Warm climate’ product sales Extremes of temperature and rainfallSale of slug pellets Incidence of late frosts Amount of salt used on roads Growing season length; day degreesPublic water use per capita Number of sunshine hoursIrrigation use on golf courses Cirrus cloud and condensation trails Gulf Stream position Sea surface temperature Salinity of sea water Plants and animals/natural environment Geographic ranges of crops Date of leaf fall Dates and levels of pollen in air Algal blooms on lakes Flowering times, eg. Hawthorn Smolt age of migrating salmon Spawning of natterjack toad Sea fish and marine plants Butterfly ranges, eg. Gatekeeper, comma, large skipper Overwintering birds, eg. Blackcap, chiffchaff, common sandpiper

23. Value of Indicators Quantitative simplification of complex changes. Indicative change for policy and decision-makers. Inform the general public; enable people to judge for themselves. Things to watch relative to predictions. But: Individually of limited value. Rarely statistically sound, in that the percentage variation due to climate can be calculated. May not vary for the reason the indicator is chosen. Thus, can be misleading. Do not explain why change is occurring. Can be overloaded with confusing opposing trends and miss the key trends. Media can highlight particular items and distort the picture.