Indicators of Climate Change in the UK

Melvin G R Cannell

OECD Pressure – State – Response Concept

Pressure State ResponseHuman activities Stocks and quality of resources Management or policies

Industrial activity

Greenhouse gasconcentrations

Climate Change

Hydrology and sea level

Plant, animal and humanbehavioural responses

Policy responses

Pressure

State Pressure

Response State Pressure

State/Response State

Response State/Response

Response

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.

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.

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/

Indicators of Climate Change in the UK

Trend over time

Sea levelThames barrier closuresSubsidence claimsOutdoor firesLyme disease casesUse of irrigation waterDate of tree leafingArrival of swallowEgg-laying dates of birds

No obvious time trend

Skiing in ScotlandGroundwater levels in chalk

Indicators of Climate Change in the UK

Hot, dry summers

More domestic tourismMore rural ozoneMore Lyme diseaseMore irrigationLess healthy beechMore insectsLate migration of salmon

Mild winters/springs

Poor skiingLower winter mortalityEarly tree leafingEarly insect appearanceEarly breeding of birds

Indicators of Climate Change in the UK

Seasonality

Proportion of gas use in winterSeasonal human mortalityTree leaf emergenceInsect appearanceArrival of swallowEgg-laying date of birdsMigration of salmon upstream

Change not wholly justified by climate -perception? Other factors?

Area of vineyardsArea of forage maizeIrrigated potato area

Air temperature in central England

No. days >20°C

No. days <0°C

Precipitation gradient across the UK

Scotland, winter

SE England, summer

Predominance of westerly weather in winter

Risk of tidal flooding in London

Thames Barrier closures per year

Scottish skiing industry

Domestic holiday tourism

Incidence of Lyme disease in humans

Warm-weather crops:

forage maizegrapes

Use of irrigation water for agriculture(England & Wales)

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

Arrival date of the swallow

Insect abundance

Egg-laying dates of birds

Other Indicators suggested during UK consultation

Climate and ocean Socio-economicAir temperature in more regions Air conditioner salesAir temperature in the uplands ‘Warm climate’ product salesExtremes of temperature and rainfall Sale of slug pelletsIncidence of late frosts Amount of salt used on roadsGrowing season length; day degrees Public water use per capitaNumber of sunshine hours Irrigation use on golf coursesCirrus cloud and condensation trailsGulf Stream positionSea surface temperatureSalinity of sea water

Plants and animals/natural environmentGeographic ranges of crops Date of leaf fallDates and levels of pollen in air Algal blooms on lakesFlowering times, eg. Hawthorn Smolt age of migrating salmonSpawning of natterjack toad Sea fish and marine plantsButterfly ranges, eg. Gatekeeper, comma, large skipperOverwintering birds, eg. Blackcap, chiffchaff, common sandpiper

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.