The search for win-win biodiversity-climate solutions

Biodiversity loss and climate change are intricately linked and we need to treat them that way when searching for solutions

If you’re reading this newsletter, you probably already realise that biodiversity loss and climate change are two of the most pressing (some might say existential) issues of our time. If not, it doesn’t take long to find the science: we’re losing species at a rate from hundreds to thousands of times above background rates. And the climate, well, it’s getting pretty hard to ignore. As humans, the main way we tend to experience climate change is in the form of extreme events. Recent years have seen, for instance, massive heatwaves across Europe, extreme wildfires across the Western US and unprecedented flooding across many parts of the world, including New Zealand.

It stands to reason that these changes to the climate will only worsen biodiversity loss, and indeed, the evidence is stacking up on this front. But why is this a problem? Because biodiversity provides us with countless ecosystem goods and services, like clean water for drinking, food, medicine, climate regulation (more on this later), among countless others.

Despite the clarity of the science here, we continue to push our planet beyond its boundaries. In fact, last year, it was declared that we have already crossed six of the nine planetary boundaries, indicating earth is beyond its safe operating space for humanity.

This is pretty morbid stuff, I know. But we can’t ignore it — we need to find solutions. Fortunately, there has been a lot of work on this front. But it turns out that many remediation actions on either of the climate or biodiversity fronts could lead to perverse outcomes — climate-specific strategies can be detrimental for biodiversity, and biodiversity-specific strategies can be detrimental for the climate. For instance, climate fixes like planting monocultures of fast growing trees for carbon capture can have detrimental biodiversity effects for a number of reasons, including planting in areas that were not previously forested leading to increased fire risk or loss of native species and associated ecosystem functions. But many climate mitigation tools also come with multiple co-benefits, including flood or coastal protection, improved water quality, improved pollination, and even creating jobs.

Life is all about trade-offs. Until we understand that, our actions will be sub-optimal. Yet, until recently, policies have tended to treat climate change and biodiversity loss as separate issues.

Fortunately, a few years back, the Intergovernmental Panel on Climate Change (IPCC) and the Intergovernmental Panel on Biodiversity and Ecosystem Services (IPBES) ran a co-sponsored workshop to explore the complex interplay between biodiversity and climate change. The result was a report that included a series of findings that considered the synergies and trade-offs in actions to mitigate either one. Understanding these trade-offs and synergies is fundamental to making better policy and decision making in this space.

Many of the synergistic solutions fall under the umbrella of “nature-based solutions”. These so-called nature-based solutions are “actions to protect, sustainably manage, and restore natural and modified ecosystems that address societal challenges effectively and adaptively, simultaneously providing human well-being and biodiversity benefits.” Green infrastructure is one such example. Cities are set to get hotter and harder to live in if climate projections are to play out. Green infrastructure like tree planting in parks, on streets and along waterways will help to reduce the heat island effects cities will experience. It will also contribute to climate mitigation goals via carbon capture, come with multiple ecological co-benefits such as providing habitat for native species, shading waterways and provision of organic matter for detritivores, and provide many well-known social benefits.

More generally, ecosystem restoration is one of the most effective nature-based solutions if done properly. Restoration of functioning ecosystems on land, in freshwater and in the oceans is one of the best win-win solutions because it directly meets both goals of increasing species richness and increasing carbon sequestration. Restoring diverse native ecosystems, rather than planting monocultures of non-native species like pines, also increases the resilience of such ecosystems to future climate shocks, in addition to increasing many ecosystem services such as flood protection and regulation, water quality improvements and reductions in rates of erosion. Moreover, diverse native ecosystems tend to be better in the long-run at sequestering carbon.

What is clear is the overwhelming need to tackle these two issues together — mitigation strategies for either climate change or biodiversity loss must not ignore each other.

Biodiversity loss and climate change are intricately linked and we need to treat them that way. As the world warms, the key contributions that nature makes to people will be disrupted, including food supplies and drinking water — climate change exacerbates biodiversity change. Similarly, as we lose species due to other human-induced threats, ecosystems begin to unravel, altering key processes that can directly impact the climate.

To reach the sustainable future we are seeking for people and nature, which is still possible, requires transformative change. We cannot reach these goals following business as usual. I just hope we start to make these changes.

The key take home for me is that taking action to slow climate change is part of the solution the global biodiversity crisis and, equally, preserving and restoring nature is part of the solution to the climate crisis. Without an holistic approach we may fail to solve either issue. But it turns out win-win strategies are possible.