If I was to mention "climate change" and "biodiversity", what picture appears first in your mind? Emaciated polar bears on shrinking ice floes? Bleached coral reefs? Or maybe stories of zebra carcasses on dry and cracked soils? My point is: you'll tend to think about species that may be driven extinct by climate change, but my guess is you won't systematically think about those species that are being forced to move and colonise new environments, potentially changing the nature and functioning of these recipient systems. And more importantly, you probably won't think about how that may impact you, your community, or your country.
Many species are indeed on the move in a desperate attempt to adapt to changing climatic conditions, and those moves are expected to increasingly pose a substantial, yet quite understated, challenge to human society. Shifts in species distributions is not science fiction, and indeed they are already happening: terrestrial species, for example, have been shown to move poleward by 17 km on average each decade, while marine species move by 72 km. The arrivals of these new species in established communities can create chaos, disturbing predation, herbivory, host-plant associations, competition, and mutualistic interactions, and can ultimately reduce the delivery of those benefits we currently derive from nature effectively for free - so-called 'ecosystem services'.
Species redistributions shouldn't only be of concern for conservation biologists - they should worry everyone. Likely to have serious consequences for the economy, food security, and human health, they are an issue we all face. Moving species could indeed lead to changes in the local supply of food and other products humans used from nature; in some cases, this may mean reduction or even disappearance of the locally exploited species, either because these had to shift their distribution in response to climate change, or because new species have moved in and driven the exploited species to extinction at a local level. This would obviously be bad news for people whose livelihoods depend on the availability of these exploited species. Moving species may then also lead to increased level of nuisance: just imagine the impacts of bigger 'blooms' of jellyfish on tourism in the Mediterranean, for example, or how people will react to greater numbers of ticks and thus more Lyme disease cases in the UK, both of which are expected to occur in the years to come.
Nations are far from being equally equipped to deal with the consequences of this redistribution of biodiversity, and the world as a whole isn't prepared to face the range of issues likely to emerge from species moving across local, national, and international jurisdictional boundaries. Environmental legislation has traditionally tended to focus on in situ conservation and the preservation of historical conditions. But with species moving beyond their traditional ranges, the emergence of novel ecosystems and the disappearance of historic ecosystems are inevitable, which means that conservation law objectives will need to be reassessed.
The changing distribution of species within countries, between countries, and between national borders and the global commons will require increased international cooperation combined with adequate resources. To help decide on what's best to do, we'll need to be able to better predict where and when redistributions will occur and what the impacts are likely to be; for this to happen, scientists will need access to better data, and develop better, more integrated models.
The public has a key part to play in helping address the challenges ahead; ultimately, it's everyone's actions and everyone's vote that will shape our collective response to any global environmental issue. So what can you do to help? Well, you can simply start by raising the issue among your colleagues, friends and family, making them aware of the environmental challenges ahead and why they matter to our society as a whole. You can also get directly involved in data collection and interpretation through citizen science schemes like Redmap, helping scientists to get a better understanding of which species are moving where, and why.
And then you can do as much as you can to reduce your own carbon emissions and talk to your governmental and/or parliamentarian representatives to get them to push for legislation to do more to reduce greenhouse gas emissions. Given the seriousness and certainty of what's ahead, it's crucial that the general public and decision-makers alike understand that this isn't the time to build fences and walls that can prevent species from moving and successfully adapt to changes to changing conditions; this isn't the time to invest and develop oil and coal industries or snub renewable energy solutions; this isn't the time to muzzle climate change scientists and undermine their capacity to do their job. This is the time to listen to scientific evidence, and take the climate crisis seriously. It's time to prioritise long-term benefits over short-term gains. It's time to act.Suggest a correction