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Changing Our Ways: Scotland's Climate Change Programme


Annex C: Impacts of Climate Change

Expected impacts in Scotland by the 2080s

  • Annual temperatures averaged across Scotland will rise by up to 3.5ûC in the summer and 2.5ûC in the winter.
  • Summers will become generally drier across Scotland. There may only be a slight reduction in rainfall in the north-west but as much as a 40% reduction in the south and east.
  • Scotland's growing season will become longer, by between 30 and 80 days.
  • Scotland's sea levels will rise, perhaps by up to 600 mm around the mainland.
  • Average snowfall amounts will decrease, perhaps by up to 90% less depending on location, and snowless winters may become normal in some parts.
  • Scotland will have more severe extreme rainfall events, with rainfall in 24 hours from storms expected to occur on average every two years up by 25%, especially in the east.

Source: The UK Climate Impacts Programme Scenarios 2002

How the world might be affected

Since the first SCCP was published in 2000, our understanding of the adverse effects of climate change has increased and there is now greater clarity about the impacts of climate change across a wide range of systems, sectors and societies. The impacts of climate change will be felt increasingly on the environment, on communities, and on businesses, with implications for the way in which natural resources as well as economic and social interests are protected.

The Third Assessment Report of the IPCC concluded that more people will be adversely affected by climate change than benefit from it, even for small increases in temperature. The extent to which human and natural systems across the world will be hit will vary greatly from place to place. The impacts of climate change will fall disproportionately upon developing countries and the most vulnerable people in those countries, exacerbating existing inequalities in health status and access to adequate food, clean water, and other essential resources.

The impacts of climate change are already being observed in a variety of sectors. Vegetation and animal behaviour is already showing signs of responding to current climate changes. Land ice is declining and changes in snowmelt, permafrost and rainfall will change the volume and timing of river flows and groundwater recharge. Some of the current and future global impacts of climate change are:

  • Coastal flooding: Global mean sea-level rise is predicted to increase by between 9 cm and 88 cm by 2100 depending on GHG emission scenarios. This could result in up to
    80 million people being flooded each year in coastal regions and the potential loss of up to 22% of the world's coastal wetlands by the 2080s.
  • Water resources: Climate change is likely to affect the volume and timing of river flows and groundwater recharge, and thus affect the numbers and distribution of people affected by water scarcity. It is estimated that 1/ 3 of the world's population are living in water stressed countries and that up to 2/ 3 of the world's population could be living in water-stressed countries by 2050.
  • Food production: The effects of climate change on agricultural production will be positive in some agricultural systems and regions, and negative in others, and these effects will vary through time. Differing trajectories of population growth and economic development will affect the level of future climate change and, simultaneously, the responses of agriculture to changing climate conditions at regional and global scales.
  • Human health: The most recent IPCC assessment (2001) concludes that in areas with deteriorating public health infrastructure, and where temperatures now or in the future are permissive of disease transmission, an increase in temperature (along with adequate rainfall) will cause vector-borne (insect-carried) diseases to spread to higher altitudes and higher latitudes.
  • Ecosystems: Global climate change will have impacts upon natural vegetation, affecting ecological and physiological processes, altering growing season length, biomass production, competition, and leading to shifts in species ranges and possible extinctions. Climate change could result in irreversible ecosystem losses in the Amazon Region, the Sahel, south central USA, and Central Australia.
  • National security: A report by the Pentagon entitled 'An Abrupt Climate Change Scenario and its Implications for United States National Security,' published in October 2003, sets out potential military implications of high risk but low probability abrupt climate change.

How the UK might be affected

The UKCIP, funded by Defra and Devolved Administrations, published the Climate Change Scenarios for the United Kingdom66 in April 2002. These scenarios provide four different climate change forecasts for the 2080s, depending on the level of world emissions: low, medium-low, medium-high or high. The forecasts are at a resolution of 50 km, meaning that the scenarios can be interpreted for Scotland. The scenarios show the following possible impacts at the UK level:

  • Annual temperatures averaged across the UK will rise by between 2 and 3.5ûC by the 2080s, depending on the future scale of global emissions of GHGs. Warming will generally be greatest in parts of the southeast, where temperatures may rise by up to 5ûC in summer by the 2080s. (To set this significant rise in context, it is worth noting that global average temperatures now are 5ûC warmer than they were during the last Ice Age.) High summer temperatures will become more frequent and cold winters will become increasingly rare.
  • Winters will become wetter and summers will become drier across all of the UK. The largest relative changes will be in the south and east where summer precipitation may decline by up to 50% by the 2080s. Heavy winter precipitation will become more frequent, but the amount of snow may decline by up to 90% in parts of Scotland.
  • Sea-levels are expected to rise around the UK, in line with global changes but with local variations due to land movement. In southeast England sea-levels could rise by between 26 and 86 cm by the 2080s. This means that, at some east coast locations, extreme sea-levels that currently have a 2% chance of occurring in any given year could occur between 10 and 20 times more frequently by the 2080s. No contribution from the melting of Greenland or Antarctic ice is assumed on this timescale.
  • Storminess may increase during the winter.

The next generation of climate change scenarios for the UK will be produced by the UKCIP in around 2008. These scenarios will, for the first time, include an assessment of the probability of each climate change occurring.

Climate prediction.net

Climate prediction.net is the largest experiment to try and produce a forecast of the climate in the 21st century. It utilises personal computers across the world to help scientists quantify the uncertainty encountered in climate models and generate the world's most comprehensive probability-based forecast of 21st century climate. The experiment, which launched in September 2003, is a collaboration between several UK Universities and the Met Office, led by the University of Oxford and funded by the Natural Environment Research Council and the Department of Trade and Industry's e-Science programme.

By July 2005, the climate prediction.net project had completed over 100,000 simulations of the Earth's climate, thanks to members of the public donating spare processing time on their personal computers. Most of the simulations returned to climate prediction.net suggest that, even with current greenhouse gas concentrations, the climate of the world will eventually be 1-2.5 degrees centigrade warmer than it would have been in the absence of human influence.

To take part in the challenge of the climate prediction.net experiment you need to download some software which runs on your PC (whenever you are not using the processor for other jobs). The climateprediction.net software is a version of the Met Office's state-of-the-art climate model. Find out more at www.climateprediction.net

On the way in

1. Creepy crawlies
Bloodsucking ticks, scorpions and poisonous spiders all night become a feature of life in a hotter UK

6. Wisteria Scale
We could see a bout of new garden pests such as Wisteria Scale, which could threaten Wisteria plants

2. Hayfever
Hayfever could be experienced for months on end as trees and grasses flower far beyond their previous seasons

7. Termites
These six legged pests are spreading north through Europe and are already in France, and could reach the UK

3. Clogged waterways
Once water frosts disappear, we could see the spread of Water Hyacinth a vigorous alien weed, which could clog out waterways

8. Vineyards
The North and East of Scotland could becomd warm and dry enough to make decent white wine

4. Pest control
We will need to take action to control infestations of flea, wasp, mice, rat populations, which thrive in the mild winters and hot summers

9. Diseases
Mosquitoes carrying diseases such as Dengue fever and West Nile virus have already invaded the US because of rising temperatures. They could become a regular feature in the UK in the future

5. Sharks
Different types of sharks could be spotted off the coast of Scotland and stingrays along the south coast of England in the warmer waters

10. Cleaner air
If we tackle those exhaust emissions we will all be able to breathe more easily

On the way out

1. Scotlands' Ski resorts
With increasingly mild temperatures and much less snow, Scotlands' ski industry has already had to diversify into other activities like mountain biking and paragliding

6. The village green
Traditional greens could become difficult to maintain, as soaring temperatures, drought and water restrictions turn them brown, promoting a move to new grass seed mixes

2. Golf courses
Golf courses could become very expensive to maintain in the long hot summers with drought and tough water restrictions affecting the quality of grass, and waterlogged conditions in winter

7. Sunbathing
Days spent lying in the sun on the beach could become a thing of the past as holliday makers are more cautious of the summer sun

3. The Snowdon Lily
The rare Snowdon Lily and many other British alpine plants could become extinct, as their mountain homes grow too hot and they face competition from other species

8. Daffodils
Warmer winter temperatures will our daffs and crocuses at risk, while other climate change impacts will affect snowdrops, rhododendrons and primula

4. Cod
Warm waters further threaten our already dwindling numbers of cod, with cod and chips potentially relegated to a thing of the past

9. Golden beaches
A trip to the seaside could be a thing of the past, as some sandy beaches are submerged under the rising seas. 70 per cent of the world's sandy shores have already been retreat over the last century

5. The Dormouse
The Dormouse could disappear as warmer summers and milder winters threaten its habitat

10. Christmas trees
Spruce tree plantations could die, as they no longer have sufficient cold spells in the winter to allow them to grow the following season

(Source: Forecasting the Future: Changing Climate, Changing Behaviour, (2003) UK Climate Impacts Programme and the Energy Saving Trust, available at: www.est.org.uk )

Social Cost of Carbon

The analytical work in support of the UK Climate Change Programme included an element of cost-benefit analysis that valued reductions in emissions using estimates from the Government Economic Service Working paper ( GES) Estimating the Social Cost of Carbon Emissions, which was published in 2002.

The paper suggested a central value of £70/tC (within a range of £35 to £140/tC) as an illustrative estimate for the global damage cost of carbon emissions. It also suggested that these estimates should increase £1/tC per year in real terms, to reflect the increasing damage costs of carbon emissions over time. Finally the GES paper recommended periodic reviews of the illustrative figures as new evidence became available.

In 2004 the inter-departmental group on the social cost of carbon ( IGSCC) commissioned further research on the issue. Two research reports Social cost of carbon: a closer look at uncertainty by the Stockholm Environment Institute and 'Methodological approaches for using social cost of carbon estimates in policy assessment' by AEA Technology have been published by Defra.

Both reports will provide relevant input into the Stern Review on the Economics of Climate Change, which as part of its terms of reference is considering evidence on environmental, social and economic consequences of climate change, including extreme events. Overall, the evidence gathered by the research reports indicates a comparable range of estimates to those currently recommended in the GES paper including the risk of higher values at the top end of the range. The government will consider whether any revision of the current advice is ncessary once the Stern review has reported in autumn 2006.