Climate Change and Nature Blog Series No 4
So far in this series of blogs we have seen how climate change over recent decades has changed the timing of biological events, how both populations and distributions of many species are changing, and how entire new communities are forming. The obvious question, then, is what happens next? Even if we stop all greenhouse gas production tomorrow, we will still see another decade of global heating. Starting with the climate projections of the Intergovernmental Panel on Climate Change, ecologists use a number of different tools to assess how ecology may be impacted by continued climate change.
Assessing the ecological impact of climate change
One approach has been to look at the impacts of recent extreme heatwaves and droughts, which are expected to become more normal in future years. Such extremes have had severe impacts on the ecology of grasslands, woodlands and crop productivity across Europe. Other approaches essentially match the UK’s future climate to places in Europe where such conditions exist currently and compare the ecologies of the different regions. Both approaches have potential problems. For example, the first assumes the effect of a single year is essentially similar to a long-term change in climate, while we know that many species that only live in the cooler wetter uplands of the UK actually breed better in occasional warm, dry years. Similarly, the second assumes that current distributions are primarily limited by climate and that species will be able to shift as the climate changes, both assumptions that are not always true.
Validating projections built using these methods is difficult: scientists producing ecological models that generate projections for, say, the 2080s are unlikely to be around to test their results anyway. Instead we rely on validation methods that require applying today’s methods to historical datasets and testing whether the changes we have seen up to today matches those expected. The net result of such validation confirms that the quantitative predictions for individual species should be treated very cautiously, but that the aggregate predictions are largely reliable. This means that while we might not be able to accurately project the micro detail such as the precise future for the Scottish Crossbill, or the future species composition of a grassland in Yorkshire, we can be pretty confident in projecting the big picture, say that that northward and upward movements of species will continue, that we will inevitably see losses of species from the northern and upland areas of the UK, and that novel communities will continue to form.
Knowing that continued change is inevitable, but that we cannot reliably predict the details of this change, a key challenge for conservation today is to make good decisions irrespective of the detailed future change. We know, for example, that future projections suggest landscapes with more topographic variability such as the North York Moors will become ever more important conservation priorities, and recent patterns confirm these areas have lower levels of local extinction than elsewhere, so improving the conservation status of such areas would be wise. Equally, we know water availability is a key requirement for many species: restoring and ensuring suitable wetlands to ensure against further changes in rainfall is therefore also wise, whatever the details of species in the future.
Overall, many of the changes necessary suggest conservation needs to shift from a species focus towards prioritisation of ecological and evolutionary processes that ensure conservation of a vibrant, but ever changing, diversity.
About the author: Colin is Reader in Ecology at the University of York, where he leads a group of researchers studying spatial patterns in ecology and conservation biology in the UK and globally. He previously worked for A Rocha Portugal and A Rocha Lebanon and is now a trustee of A Rocha UK. As a member of his local parish church, Colin also advises the Diocese of York on environmental matters.
This blog was written for A Rocha UK’s Wild Christian email, June 2021. Read part 5 in our climate and nature blog series here. Sign up here to receive future Wild Christian emails