Written by Wildwatch volunteer Sean Garvey in the summer 2019, as an update to our page on climate change at St Nicks
This heatwave seems as good a time as any to consider climate change. Extreme weather events of all kinds are set to become more frequent as global warming affects us all. Here in York, floods in recent years, and the recent blazing heat are just a foretaste of what is to come. Wildlife is already being affected by what we humans are doing to the climate; the future will bring profound, and often dire, consequences for our fellow creatures.
At St Nicks, the weekly Wildwatch group has, for many years, been observing changes in our amazing local flora and fauna. Over the last few summers it’s been rather exciting to see insects such as Cinnamon Bug and the hornet-mimic hoverfly, Volucella zonaria, for the first time here. These are more typical of southern England, and such records reflect national trends. Some of the science behind the shifting distribution of beasties like these, butterflies and damselflies is discussed on this page.
Some birds also seem to be adapting successfully to our generally milder winters. Chiffchaffs and Blackcaps, once only summer visitors to the UK, can now sometimes been seen throughout the year around York. Such sightings at St Nicks reflect broader patterns in bird distribution that have been uncovered by many ornithologists.
So we’ve realised that some bird and insect species can simply fly further north as the world warms. Field guides (even recent editions) often say that certain species are scarce or absent north of the Humber: this is no longer correct. For such species, “the Tyne is the new Humber” in terms of biogeography. However most animals – even those with wings – can’t adapt so easily. Birds and insects are suffering alarming declines in both numbers and biodiversity all over the world.
And what of all the wildlife that can’t fly? Like plants? It’s harder to spot evidence of long-term floral changes here at St Nicks. However we Wildwatchers are doing our bit at keeping up the long tradition of amateur-naturalist (citizen-scientist, if you prefer) involvement in phenology. This is the study of how plants and animals respond to the seasons, and to long-term climate change. Just recording the first flowering of a Primrose can contribute to the enormous amount of data already collected about this, over more than two centuries. On average spring is arriving almost two weeks earlier (and autumn a week later) than it was in the 1970s.
Many organisms are struggling to cope with such rapid and sustained climate change, as much research is showing. They evolved in (mostly) more climate-stable times when the links between temperature, what there is to eat, and what’s around trying to eat them was more predictable than it is now. Hedgehogs and queen bumblebees, for example, have always sometimes come out of hibernation too early, during mild winter periods when there is nothing to eat. Such ill-adaptive behaviour is going to be far more common for all sorts of creatures, as global warming unravels the subtle and complex web of interdependence between species.
Climate change is already having an impact, and not only on the lives of humans. Even relatively optimistic predictions, by the Met Office and others, point to global warming intensifying for decades to come. For Britain this means that winters are, on average, going to be milder and wetter, with summers tending to be hotter and drier. Extreme weather events of all kinds – droughts, floods, storms – are very likely to become more frequent.
So what does this mean for a nature reserve like St Nicks? There has to be a lot of uncertainty about this. This is particularly the case when we consider our woodland. After all, the oaks and yews planted here in the 1990s have the potential to live for a thousand years or more – but not if current global warming continues. In just a fraction of such trees’ lifespans – a mere 50 to 100 years, say – they might no longer be able to thrive, as some sobering models of future UK tree distribution suggest. Add in the effect that tree pests and diseases, such as Ash Dieback, are going to have, and Yorkshire woods will, within decades, probably sustain a very different community of species -and not just the trees.
Grassland and wetland habitats at St Nicks are going to face similar challenges, especially as long spells of drought and flood are likely to become more frequent. In all places, a few sassy generalist species will do well. Some of these will probably be native species that are already common, such as Magpies; others could be non-natives like our Grey Squirrels. But organisms that are already scarce, or have specialist habitat requirements, are going to be far more vulnerable to the more extreme weather events that they are going to have to face.
It’s not all doom and gloom, however. For a small urban nature reserve, St Nicks has a rich mosaic of diverse habitats that are the home to a wide variety of wildlife. Such diversity is crucial to the resilience of ecosystems – at a local, no less than a global, scale. Together with partner organisations, St Nicks is involved in developing green corridors around York. These will help link up many valuable, but fragmented, green spaces – thus allowing many animals and plants (fungi, too, perhaps?) to range more easily between them, as they will increasingly need to do. All this represents a small part of important national and international plans to provide the connections between wildlife, people and places that we all need.
The healthy plants and soil of St Nicks – especially the maturing trees – are, for now, carbon sinks. In their own small way, they are mopping up some of the excess CO2 we humans are producing.
Hard work, skill, and money transformed this landfill site into a thriving nature reserve. (But hey – if you used to be a municipal dump, then the only way is up!) All three things will be needed to reduce some of the worst impacts of climate change – at St Nicks and far beyond. Better to start on such mitigation now, rather than a future when it will be far more costly – in every way – if possible at all. But we got to the moon and back, 50 years ago: what can’t we achieve now?
Not that mitigation alone is going to halt the climate crisis. As you know. But we all – at St Nicks and elsewhere – have got to start somewhere. Got to, not just for our own human self-interested sakes, but for all our lovely (non-human) animal and plant neighbours. Actually, it boils down to self-interest after all: we need the lovelies as much as they need us.