A Global Deal For Nature
Today nature is suffering accelerating losses so great that many scientists say a sixth mass extinction is underway. Unlike past mass extinctions, this event is driven by human actions that are dismantling and disrupting natural ecosystems and changing Earth’s climate.Greg Asner, Director, Center for Global Discovery and Conservation Science and Professor, Arizona State University
My research focuses on ecosystems and climate change from regional to global scales. In a new study titled “A Global Deal for Nature,” led by conservation biologist and strategist Eric Dinerstein, 17 colleagues and I lay out a road map for simultaneously averting a sixth mass extinction and reducing climate change.
We chart a course for immediately protecting at least 30% of Earth’s surface to put the brakes on rapid biodiversity loss, and then add another 20% comprising ecosystems that can suck disproportionately large amounts of carbon out of the atmosphere. In our view, biodiversity loss and climate change must be addressed as one interconnected problem with linked solutions.
Global deal for nature
Our Global Deal for Nature is based on a map of about a thousand “ecoregions” on land and sea, which we delineated based on an internationally growing body of research. Each of them contains a unique ensemble of species and ecosystems, and they play complementary roles in curbing climate change.
Natural ecosystems are like mutual funds in an otherwise volatile stock market. They contain self-regulating webs of organisms that interact. For example, tropical forests contain a kaleidoscope of tree species that are packed together, maximizing carbon storage in wood and soils.
Forests can weather natural disasters and catastrophic disease outbreaks because they are diverse portfolios of biological responses, self-managed by and among co-existing species. It’s hard to crash them if they are left alone to do their thing.
Man-made ecosystems are poor substitutes for their natural counterparts. For example, tree plantations are not forest ecosystems – they are crops of trees that store far less carbon than natural forests, and require much more upkeep. Plantations are also ghost towns compared to the complex biodiversity found in natural forests.
Another important feature of natural ecosystems is that they are connected and influence one another. Consider coral reefs, which are central to the Global Deal for Nature because they store carbon and are hotspots for biodiversity. But that’s not their only value: They also protect coasts from storm surge, supporting inland mangroves and coastal grasslands that are mega-storage vaults for carbon and homes for large numbers of species. If one ecosystem is lost, risk to the others rises dramatically. Connectivity matters.
The idea of conserving large swaths of the planet to preserve biodiversity is not new. Many distinguished experts have endorsed the idea of setting aside half the surface of the Earth to protect biodiversity. The Global Deal for Nature greatly advances this idea by specifying the amounts, places and types of protections needed to get this effort moving in the right direction.
Technology is the easier part of the challenge. Organizing human cooperation toward such a broad goal is much harder. But we believe the value of Earth’s biodiversity is far higher than the cost and effort needed to save itGreg asner