Preparing for the impacts of climate change on the UK’s natural environment

This blog introduces the last of four research projects commissioned by the Adaptation Sub-Committee to inform the 2017 UK Climate Change Risk Assessment. Here’s an extended summary of all four projects.

The UK’s rich wildlife and distinctive landscapes are a source of inspiration to millions of people. Many believe that society has a moral duty to protect nature for current and future generations. There is also a growing recognition that ‘natural capital’- our water, soils, land, sea, air and the wildlife they sustain – is as important for people’s well-being and quality of life as economic and social capital.

Wildlife and natural systems are shaped by the climate and so are very sensitive to any changes. The increase in average temperatures experienced here in the UK over the last few decades has already had a noticeable impact on our wildlife. New species are arriving in southern Britain from mainland Europe and many groups of native species are steadily shifting their distributions northwards to remain within their viable ‘climate space’ – the climatic range within which a particular plant or animal can survive.

New research commissioned by the Adaptation Sub-Committee (ASC) of the Committee on Climate Change finds that further climate change in the future is expected to have major implications for British wildlife. The report, ‘Climate change impacts on the goods and services provided by the UK’s natural assets’ prepared by consultants AECOM in partnership with the University of York and the University of Exeter, is part of our work to inform the Government’s next climate change risk assessment in 2017.

AECOM’s study models the effects of changing average temperatures, water availability and seasonality for over 4,700 native British species. It finds that many species groups, particularly spiders, ants, moths and wasps, can expect to see their climate space significantly expand. This means they may be able to colonise new areas and so potentially benefit from the projected changes in climate. Birds, plants, butterflies, bees and dragonflies will not see as much of a change in their climate space overall, although there will be individual species that are expected to gain.

In theory, a warmer climate could result in richer and more diverse wildlife than we currently have in the UK today. However, wildlife will only be able to benefit from expansions in climate space if there is enough habitat in the right area and in good ecological condition to colonise. If our woodlands, grasslands and heathlands are ecologically degraded and if our rivers, lakes and estuaries are polluted, then species will find it harder to adapt. Climate change could, therefore, act as an additional pressure and accelerate species loss. As the RSPB recently highlighted, we must reduce adverse pressures and improve the condition of our habitats to give wildlife the best chance of adapting to climate change.

The AECOM report also found that some types of species may experience a shrinking in the area of suitable climate space. This is particularly the case for mosses, which mostly favour wet and cold conditions. We know from paleo-ecological evidence stretching back over 9,000 years that some moss species are capable of tolerating warmer and drier conditions. The difference now is that mossy habitats, such as peat bogs and fens, are in a poor ecological condition. Some 70% of deep peats in England are currently in a physically degraded state. This is mainly due to a long history of pollution and adverse management, including extensive drainage, over-grazing and rotational burning, as we highlighted (for England) in the ASC’s recent progress report. It is doubtful that in their current condition mossy habitats will have the resilience to cope with the impacts of climate change.

This matters for a host of reasons. Firstly, the UK’s mossy habitats are of international importance for biodiversity. For example, 13% of the global resource of blanket bog habitat is in the UK. Losses of these habitats and their species would therefore have global consequences, and the UK has international obligations to protect them.

Secondly, mossy habitats provide extremely important goods and services we rely on. One such service is carbon storage. Healthy mosses capture CO2 from the atmosphere and form peat. These peatlands store an estimated 3.2 billion tonnes of carbon in the UK. However, if the mosses dry out, peat habitats become a net emitter of CO2 through erosion and oxidation. The IUCN has estimated that losing 5% of the carbon stored in UK peatlands would be equivalent to a whole year’s worth of current UK greenhouse gas emissions.

Levels of dissolved carbon in upland rivers and reservoirs have doubled over the last 30 years, suggesting that increasing amounts of soil carbon are already being eroded from degraded peatlands. When drinking water with high carbon content is disinfected during treatment, carcinogenic by-products are produced. Water companies are therefore required to remove carbon from the water before it can be used. This is an expensive and energy intensive process, which is expected to become more technically challenging and costly if the rates of carbon loss increase in the future. Due to the potential impact on customer bills, water companies are increasingly investing in programmes to restore degraded peat habitats in an attempt to reduce carbon losses at source.

So, while in theory there may be potential benefits to our natural environment from climate change, in reality we can expect the impacts of rising average temperatures to make existing problems worse. Further action is needed to restore degraded habitats so our wildlife has the best chance of adapting to the challenges ahead.

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