In this second blog about the pressures on nature paper published yesterday (here), I move from farming to climate change.
The new analysis shows that climate change is already the second biggest factor affecting wildlife across the UK. Yet the detail may be a surprise to some – climate change seems to be benefiting as many, if not slightly more, of our UK species than it is disadvantaging – hence this headline in today’s Daily Telegraph “Climate change has helped more species than it has harmed”.
Scientific studies have repeatedly shown climate change to be a major problem for wildlife: so what is going on here?
It’s worth noting that climate change is the factor assessed to have the second biggest negative impact on the 400 species studied (after agriculture, which is clearly the most important driver). So that is an important message: alongside whatever benefits it may bring, climate change is already causing serious negative impacts on some of our wildlife.
But why would climate change actually benefit some of our other species? The paper identifies climate change as having a larger positive impact on the UK’s wildlife than any other driver. Actually, there are a few reasons.
Firstly, let’s consider the UK’s geographical position in the north-west of Europe. Here, we have more species that are at the northern edge of their distribution, or range, and fewer that are near their southern limit. We’d expect a warming climate to enable those species at their northern range edge to expand north – and that is exactly what we are seeing. However, we are not seeing so many species ‘drop-off’ the southern end of their range, simply because we have fewer of these species. We are however seeing some changes in hillier and mountainous regions, with some uplands species such as the mountain ringlet butterfly seeming to be retreating up the hill – a lower altitude limit acting similarly to a southern latitude limit in a warming climate.
Mountain ringlet by Oliver Smart (rspb-images.com)
This picture is further complicated by the fact that we are also seeing that species seem to be moving forward at their leading, northern range edge more quickly than species retreat from their southern, trailing edge. Part of this comes down to how we record change – it only takes a few individuals to move north for us to register a range expansion, whereas an entire population has to vanish from an area before we register a range retreat. So we anticipate seeing the tail-end, negative impacts increasing over time.
Then secondly there’s the exciting arrival of species unfamiliar in Britain – for example the recent arrival and successful breeding of black-winged stilts and great white egrets. This leads us to consider our wider role in the stewardship of western Europe’s wildlife. At this larger geographical scale, many of these north-advancing species also have the tail end of their range in southern Europe. For Dartford warblers, for instance, we’re seeing exactly what we might expect: range expansion across England, but with larger declines across Spain (see here). Europe faces much more severe future climate change than here in the UK, particularly in the south, so our role will grow as a refuge for European wildlife escaping changing climatic conditions in their current range. You could say that the UK can be seen as an ark for many species affected by climate change.
And thirdly, it is worth remembering that we are still in the early days of climate change. The impact on our wildlife has only been apparent for around 30 years: we are witnessing the first signs of change, and there’s a good deal more to come. For a world with 3°Celsius average global temperature rise, Europe’s breeding birds are expected to need to shift location by an average of nearly 550 km north-east to stay within suitable climate conditions. What’s worse is that there will be less space for them overall: the extent of those suitable climate conditions is projected to decrease by 20%. And of course, each species will also need appropriate habitat in those new areas of climate suitability, as well the ability to get there –consider the dispersal challenge for a sand lizard that already finds it tricky to cross a road.
So let’s welcome whatever benefits climate change brings for the UK’s wildlife. But we mustn’t let this cloud our overall view of climate change and the devastation that it could bring to people and wildlife.
This is why the RSPB will continue to work with others to help wildlife become more resilient and adapt to climate change whilst also pressing governments across the UK to meet their targets for reducing greenhouse gas emissions.
You can read more about our work on climate change here.