Forests, mangroves, and wetlands are sometimes seen as the easy option for sequestering carbon—yet using nature to tackle climate change can be surprisingly controversial.

Magloire-Desire Mounganga, an expert from Gabon's National Agency for National Parks, walks over mangroves in the Angondje Nton district of Libreville on May 17th, 2018. (Photo: Steve Jordan/AFP/Getty Images)

Restoring forests, maintaining peatlands, planting mangroves: These are some of the "nature-based solutions" that could help the world combat climate change.

As well as sequestering carbon released into the atmosphere by burning fossil fuels, restoring natural ecosystems creates new habitats, protects against flooding, provides opportunities for food and pollination, and helps generate a trove of material for future medicines. What's more, increasing the acreage of high-quality natural landscapes doesn't require any dramatic change to the electricity grid, or demand that everyone buy an electric car—not to mention nature's remarkable ability to make life generally more pleasant.

A recent study suggests that natural solutions can provide "over one-third of the cost-effective climate mitigation needed between now and 2030 to stabilize warming to below 2 degrees Celsius," reducing the need for riskier options, like geo-engineering or bioenergy with carbon capture and storage.

This contribution could be vital to meeting global emissions targets. Relying on emissions reductions alone will likely see the planet zoom past a rise of two degrees Celsius—the limit that countries agreed to in 2015—meaning that we'll almost certainly have to rely on methods that remove carbon dioxide from the atmosphere.

So why is it so difficult—and often so controversial—to bring nature into the discussion on tackling climate change?

Only two-thirds of countries talk about nature in their climate targets, known as nationally determined contributions (NDCs), according to analysis by academics at the University of Oxford and the International Union for Conservation of Nature. The results of their forthcoming study have yet to be published, but were announced by the authors at the recent United Nations climate conference, COP24, in Katowice, Poland.

Of the 130 nations that included nature-based solutions in their NDCs, just 76 plan to use them to both reduce emissions and adapt to climate change, says Nathalie Seddon, a professor of biodiversity at the University of Oxford, who led the study. More than 60 of the countries that signed up to the Paris Agreement do not mention nature at all in their pledges.

The researchers also discovered that developing nations were leading the way on incorporating nature into their climate strategies. One hundred percent of low-income nations said they planned on using nature to tackle climate change, compared to 27 percent of high-income nations. Yet, while forests were commonly cited in these climate plans, other ecosystems were "rarely included," Seddon says. And targets were rarely grounded in science, she adds, making them difficult to achieve.

This goes against the perceived wisdom that nature can be a quick fix in tackling climate change, says Alexis Bonnel of the French Development Agency, a public bank that has financed nature-based solutions.

"Why isn't the financial community spontaneously investing?" Bonnel says. "The problem is when you are hungry and you are in front of a tree, which [cherry] would you pick: The one that is hanging low, or the one that looks mature enough to be eaten? This is the issue with nature-based solutions: It is a low-hanging fruit, but it's not mature enough to be embedded in what businesses and financiers are doing."

Using nature in climate mitigation strategies requires a way of thinking that is unfamiliar to financiers, Bonnel says: It requires long-term commitments, and an approach to funding nature as a holistic system rather than one that stops at national boundaries.

And besides, just talking about nature can make businesses uncomfortable. "The word 'nature' somehow doesn't seem to fit with the language of the business community," Bonnel says.

Lack of financing for nature-based climate solutions is just one obstacle among many. Accounting for the emissions reductions achieved through ecosystem restoration poses another challenge, says Tatiana Minayeva of Wetlands International, who has studied how countries are using peatland restoration to meet their climate targets. Her conclusion is that they're not, really.

"It’s quite depressing reading," Minayeva says. Nations aren’t making peatland restoration part of their climate action plans simply because they don’t understand how to account for the benefits the ecosystem can bring.

"There are no champions really," she says. "It's really not a low-hanging fruit."

Then there's the issue of offsets: Should emitters be able to pay to restore ecosystems that sequester carbon in lieu of reducing their own emissions? The subject has proven bitterly divisive in the climate-advocacy community, with some seeing it as a means of generating much-needed finance for preserving nature, and others regarding it as a get-out-of-jail-free card for industry.

"It really is time that governments stopped trying to find more ways to offset their fossil fuel emissions through, for example, protecting seagrass and mangroves in coastal areas," says Bill Hare, chief executive officer of Climate Analytics. "They do need protection, but if that work is then used to offset emissions, then ultimately the resulting warming will kill them. We need a clear firewall between these two activities."

The Nature Conservancy, another non-governmental organization that campaigns on climate change, helps to develop projects that generate carbon offsets. Emily Landis, who leads the Nature Conservancy's coastal wetlands strategy, endorses this approach. "We need to do something, and if carbon offsets is a way to get enhanced finance in the short term, I think, yes, we have to be careful of greenwashing but we don't have much time," she says.

It's also important that nature-based solutions aren't regarded as purely a means to reduce carbon emissions, but also as an opportunity to install fully functioning ecosystems, with all the benefits those can bring.

"Certainly, there's been a lot of focus in the U.N. talks on forestry and the ability of trees to draw CO2 from the atmosphere, but there are ways of doing that that are not very helpful," says Kat Kramer, global lead on climate change at Christian Aid, who recently authored a report on nature-based solutions. "You put up plantations of the wrong species, and it can cause all kind of problems with the water table, changing soil structures, and potentially even increasing water runoff rather than decreasing it."

Countries are set to submit their next round of climate pledges in 2020. This creates an opportunity for nature to take root in the global effort to tackle climate change. But the message from experts is clear: Nature has its own agenda, and we can't rely on the Earth alone to do the serious work that lies ahead for politicians and energy companies.

New Landscapes is a regular series investigating how environmental policies are affecting communities across America.