No matter how many solar panels, wind turbines and electric cars are built between now and 2030, the world won’t meet its increasingly ambitious climate targets without a lot of help from forests, fields and oceans. 

“Achieving net-zero by 2050 will not be possible without nature,” Interior Secretary Deb Haaland said on April 22 at the online climate summit hosted by President Joe Biden as she opened a session on nature-based climate solutions. “The impact of greenhouse gas pollution from extreme heat and storms is having a devastating effect on our lands and oceans. At the same time, nature provides us with solutions.” 

Nature-based solutions aim to slow climate change as well as protect biodiversity and human communities from its impacts by bolstering ecosystems that store carbon. Those efforts range from shielding Central Africa from the encroaching Sahara with a wall of trees to rebuilding coral reefs around Florida, restoring beds of seagrass in the United Kingdom and planting swaths of bamboo in California. 

Oceans, forests and fields already stash away about half of the carbon dioxide produced by burning fossil fuels, and international plans to limit global warming depend on even more help from such ecosystems to slow the buildup of greenhouse gases in the atmosphere. Most countries claim nature will help them lower their emissions in coming decades. But recent studies suggest that neither forests nor oceans will be able to take up as much carbon in the future as they do now, making such commitments uncertain bets.

Related: Targeted Ecosystem Restoration Can Protect Climate, Biodiversity

Indigenous Peoples and Land Rights are Key

How much nature can help slow global warming may hinge on whether local communities can regain rights to lands they have traditionally occupied, Indigenous leaders said at Biden’s climate summit. Many researchers as well as Native peoples have noted that the most effective nature-based solutions have been developed by Indigenous communities that practiced sustainable conservation for thousands of years before the industrial revolution started warming the atmosphere.

“This is a critical issue for Indigenous people,” said Tuntiak Katan, general coordinator of Global Alliance of Territorial Communities, during the natural solutions panel at the summit.

“Historically, we have been saying that the way we act as people, as humankind, our economic policies are not the right ones for the planet,” said Katan, who represents Indigenous and local communities in the Amazon Basin, Brazil, Indonesia and Mesoamerica. “Science is proving now that we have been right.” The first step toward effective natural solutions is the legal recognition of Indigenous land rights, Katan added.

“It is within your responsibility and political will to change the trajectory of destruction and climate collapse on the planet,” he said. “If we start acting now, we’re saving ourselves. It’s not a matter of saving animals or the planet, it’s a matter of saving humanity.”

The summit also made clear that Native peoples have a particularly strong incentive to act.

Tribes and Indigenous communities are particularly vulnerable to the impacts of climate change, which is affecting “their homelands, sacred places and the resources they depend on,” Environmental Protection Agency Administrator Michael Regan said at the summit.

The Quinault Indian Nation in the Pacific Northwest felt some of those impacts in 2006, said Fawn Sharp, president of the National Congress of American Indians. The “harsh reality,” after millenia in which millions of sockeye salmon spawned in the Quinault River, was that the number dwindled to only about 4,000.

“Salmon cannot emerge out of the river to stand in the halls of Congress,” she said. “We are their voice. We have a sacred duty to not only fight, to not only protect all of humanity, but to protect all things living.”

Sharp described watching the rising sea inundate one of the Quinault Nation’s coastal communities, and seeing miles of coastline littered with marine animals killed by oxygen depletion in the ocean. 

“Every one of these frontline impacts has taken a significant toll and traumatized our entire nation,” she said. “We have witnessed a world completely unhinged from the values, teaching and sense of responsibility we all share in caring for our relatives, the ocean, the forests and the skies.” 

For indigenous communities, “nature protection is not a policy. It’s a way of life,” said Hindou Imarou Ibrahim, of the Indigenous Women and Peoples Association of Chad, where rising heat and shifting weather patterns have already disrupted water supplies and uprooted communities.

“You are smart because you start to understand that without Indigenous peoples, there is no way we can solve the climate change mess the industrialized countries have put us in,” she said at the summit. “We don’t have Ph.D.s, but we have our traditional knowledge. We have our grandmothers who can tell us how to restore the tropical forests. We know how to build resilience because we know how to listen to our mother Earth.”

But, she added, “If you want our help, we have some conditions. Firstly, it is time for governments and companies to start listening to us, and to stop stealing our land for agriculture and fossil fuel. This is needed right now.”

‘Not Every Measure That Uses a Tree Qualifies as a Nature-Based Solution’

Nature-based solutions are “part of the portfolio of measures that we need to pursue to decarbonize our economies rapidly and effectively,” said climate researcher Joeri Rogelj, with the Grantham Institute at the Imperial College London and the International Institute for Applied Systems Analysis in Austria. ​But, he added, they are not a silver bullet.

“First, not every measure that uses a tree qualifies as a nature-based solution,” he said. “Planting monoculture forests that reduce local biodiversity, and local populations’ access to agricultural land or water would not meet the mark.” Species richness declines, for example, when palm oil plantations replace old growth or secondary forests. 

And, because those same ecosystems we hope will help us are very vulnerable to climatic changes projected to occur in coming decades. “It is unclear whether these ecosystems will indeed continue to store as much carbon as we expect them to,” he said. “While we should not avoid nature-based solutions, we shouldn’t bet our future on their success.”

Related: Unchecked Global Warming Could Collapse Whole Ecosystems, Maybe Within 10 Years

A 2017 study showed that natural climate solutions can provide about one-third of the cost-effective climate mitigation needed between now and 2030 to stabilize the climate at less than 3.6 degrees Fahrenheit of warming. More recent research even mapped out a detailed global plan to preserve and restore forests to sequester carbon. 

“So far, plants are the only technology we have to draw down large amounts of carbon from the atmosphere, others don’t exist,” said Constantin Zohner, a climate change biologist with the Crowther Lab at ETH Zürich. “They are one of our allies in the fight against climate change. But instead of using that offer, we tear down more plants and forests every year.”

And even if we use plants to slow climate change, Zohner said natural solutions can “never be a substitute for drastic cuts in emissions.”

Efforts to protect and restore forests must also be socially and ecologically responsible, he added. “You have to plant the right forest in the right location, and only if local people are involved and profit from it will it be sustainable,” he said. “Otherwise, the forest will just be removed 10 years later.”

A 2019 Intergovernmental Panel on Climate Change special report detailed how ecosystems on land could take more carbon out of the atmosphere, but also how vulnerable those ecosystems are, said Claire Fyson, with Climate Analytics, a nonprofit science and policy institute.

“Whenever I talk about nature-based solutions, the most important caveat is that they are not going to work if we warm too much,” she said. Thawing permafrost and heat-stressed forests are already losing their ability to keep carbon out of the atmosphere. “If we get close to 2 degrees Celsius of warming, it’s going to be a big challenge for the world we rely on.”

Another big concern, she added, is greenwashing, or symbolic environmentalism, when governments or countries use nature-based solutions like tree-planting planting “to obscure continued or increased emissions,” she said.

Microsoft, for example, has a plan to be “carbon negative” by 2030 that relies partly on planting vast swaths of carbon-absorbing forests, but research suggests the company’s estimates of how much carbon the trees can sequester and how much the company will emit may be overly optimistic.

The adaptation aspect—bolstering nature to protect ecosystems and communities—should drive investment into nature-based solutions, rather than the financial incentive of carbon credits, Fyson said. 

As for restoration, recent history offers some hope, even in areas that currently appear to have little, Fyson said.

“Brazil had a lot of success improving forests in the early 2000s, with good enforcement and monitoring,” she said. “We need to make sure people who are relying on the land are the ones making the decisions.”

In any scenario, the path of nature-based solutions is “fraught with uncertainties,” she added.

“We’re sort of in a bind with nature,” she said. “We need it to get where we want to go, but if we don’t do everything else we can to help it, we will lose it.”