Global experts identify key options to tackle biodiversity and climate crises
A University of Plymouth researcher is among the authors of a new report into the causes, effects and solutions of our biodiversity and climate crises and the importance of tackling them in tandem.
The findings, published ahead of the G7 summit of world leaders, show that unprecedented changes in climate and biodiversity, driven by human activities, have combined and increasingly threaten nature, human lives, livelihoods and well-being around the world.
However, previous policies have largely tackled biodiversity loss and climate change independently of each other, and addressing the synergies between mitigating against them—while considering their social impacts—offers the opportunity to maximize benefits and meet global development goals.
The authors also warn that narrowly-focused actions to combat climate change can directly and indirectly harm nature and vice-versa, but many measures exist that can make significant positive contributions in both areas.
The report is the product of a four-day virtual workshop between experts selected by a 12-person Scientific Steering Committee assembled by the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) and the Intergovernmental Panel on Climate Change (IPCC).
The steering committee's members include Professor Camille Parmesan, NMA Chair in Public Understanding of Marine Science and Human Health at the University of Plymouth, who also co-edited the workshop report.
She is renowned for her research on the impact of climate change on wildlife, and was the first scientist to demonstrate that species are shifting their natural ranges in response to changes in temperature. She said:
"It's very clear that we cannot avoid 'dangerous' climate change—meaning keeping warming below 1.5°C, or even 2°C—without sucking up some of the carbon we've already put in the atmosphere. At this point, reducing emissions is not enough. The best way to do that is through nature-based solutions, using the power of plants to reduce CO² in the atmosphere.
"This report is a microcosm of what we need to be doing as a global society, with those working on how to protect and improve biodiversity getting together with those working to protect the planet from dangerous climate change."
Among the most important available actions identified in the report are:
- Stopping the loss and degradation of carbon- and species-rich ecosystems on land and in the ocean;
- Restoring carbon- and species-rich ecosystems;
- Increasing sustainable agricultural and forestry practices;
- Enhancing and better-targeting conservation actions, coordinated with and supported by strong climate adaptation and innovation;
- Eliminating subsidies that support local and national activities harmful to biodiversity.
Some focused climate mitigation and adaptation measures identified by the report as harmful to biodiversity and nature's contributions to people include:
- Planting bioenergy crops in monocultures over a very large share of land areas;
- Planting trees in ecosystems that have not historically been forests and reforestation with monocultures—especially with exotic tree species;
- Increasing irrigation capacity. A common response to adapt agricultural systems to drought that often leads to water conflicts, dam building and long-term soil degradation from salinization;
- Any measures that focus too narrowly on climate change mitigation should be evaluated in terms of their overall benefits and risks.
Finding solutions to our biodiversity and climate crises
Professor Camille Parmesan writes:
Nature-based solutions are about so much more than reducing CO² in the atmosphere. Protecting natural systems and restoring them to their healthiest improves their ability to help society.
We're finding that using natural systems to help adapt to the increases in extreme climate events that we're experiencing (because of human-driven climate change) is less costly and more effective than technological fixes or traditional large infrastructure.
So restoring natural wetlands and vegetation around rivers serves as flood management. Restoring coastal wetlands, mangroves, seagrass and kelp beds helps buffer storms from the sea. Developing green and sponge cities, which use trees and natural vegetation to shade our building and soak up heavy rains.
All of these nature-based solutions are cheaper and often more effective than traditional storm barriers and air-conditioning. And there are the additional huge benefits to helping biodiversity cope with climate change, and to reducing climate change itself.
We've learned that healthier natural systems are more resistant and resilient to human-driven climate change, and they help reduce or mitigate the impacts of emissions that humans continue to release.
It's a win-win solution—a partnership between nature and humans rather than a competition. And who wouldn't rather walk along a tree-lined meandering stream instead of a concrete canal?
One of the key messages of this report is that these nature-based solutions are critical, but only work well if we do the right thing in the right place. Trees are great in some places, but not the right thing to plant in others.
Much of Europe would be heavily forested if we stopped using it for grazing and hay-making. But if we allow that, then not only do we lose valuable food production, but also lose much of our native biodiversity, for example many insects and birds.
In the U.S., the vast native prairies we used to have are much more resistant to droughts and heat waves than even planted exotic grasses, much less trees. Trees might live for a few years, but would die off with the drought and heat extremes that are only getting worse. Then you have a stand of dead trees, giving wildfires—that are already getting worse because of climate change—even more fuel.
So restoring nature is about much more than planting trees. It's about being smart, thinking about what is best to be done where, and working together as a society—scientists and engineers, farmers and hunters, policy makers and ordinary citizens—to do the right thing in the right place and at the right time.