Do you know how far restoring old farmland could go toward solving the global climate challenge? According to a study published in Nature last month, restoring 15% of converted lands in key priority areas could store enough carbon equal to 30% of the total CO2 increase in the atmosphere since the Industrial Revolution.

Ecosystem restoration is gaining recognition as an option to address climate change and biodiversity loss. Ecosystems serve as carbon sinks, drawing in and reducing the amount of atmospheric carbon dioxide driving climate change. They can also provide habitats for a wide variety of species. However, the degradation of landscapes, usually for agricultural or development purposes, weakens the provision of these services. Making use of what nature naturally provides by restoring degraded ecosystems can be a cost-effective way to help us address environmental problems. The only issue? Scientists and government officials aren’t sure which ecosystems would provide the most bang for buck as far as restoration goes.

The new study published a month ago identifies key areas for ecological restoration and confirms the immense potential of nature to address climate change and biodiversity loss. The study recommends restoration efforts that would save 60% of species from extinction due to climate change.

According to the researchers from Pontifícia Universidade Católica in Rio de Janeiro, Brazil, wetlands and tropical forests are priority areas for restoration. These biomes are home to many carbon stocks capable of storing the atmospheric carbon dioxide driving climate change. They also have rich levels of biodiversity.

What sets this study apart from previous nature-based climate solutions studies is its broad survey approach of different biomes rather than only one biome. The study identifies restoration opportunities for five landscapes: forests, wetlands, grasslands, shrublands, and arid areas. Ecosystems that have been transformed through human actions such as agriculture are the main focus of the study, as their degradation reduces their ability to store carbon and provide habitat.

Fig. 1: Global priorities for restoration according to the combined criteria of biodiversity, climate change mitigation, and minimization of financial costs. Dark red signifies converted lands of highest priority for restoration (top 5%) while blue signifies converted lands of lowest priority (85–100%).

Researchers compared the effects of restoration efforts on different biomes by examining changes in projected species extinctions and the amount of greenhouse gases captured and stored.

An algorithm was used to identify optimal areas for restoration across 1,200 global scenarios. The algorithm applied three main criteria: biodiversity conservation, mitigation of climate change, and cost.

The research suggested that protecting 30% of the priority ecosystems of wetlands and tropical forests, in conjunction with protecting ecosystems still in their natural, undisturbed form, would reduce carbon emissions equivalent to 49% of all the carbon that has built up in our atmosphere over the last 200 years.

The benefits are cost-effective. Researchers argue that strategically prioritizing wetlands and tropical forests for restoration can be 13 times more cost-effective than the current ecosystem restoration approach, which lacks a unified global strategy.

Researchers warn that to completely tackle climate change, restoration efforts alone, such as rewetting wetlands drained for agriculture, will not be enough. These efforts would need to be accompanied by strong reductions in fossil fuel emission, which is still the highest priority for limiting global warming. In an interview with InsideClimate News, Robin Chazdon, co-author of the research paper, stresses the need for transformative, societal changes. “The study is just a map, a motivator. To really make any of this happen, we need political, economic, and cultural change.”

Effects from reducing CO2 through the restoration of ecosystems are not necessarily permanent. If ecosystems are destroyed, the carbon will be released back into the atmosphere. If ecological restoration is pursued, mechanisms have to be put in place to ensure that they are protected.

The study confirms that ecosystem restoration can play a major role in addressing climate change and biodiversity issues – and the best part is, we can do it at a low cost. We’ll still need to reduce our fossil fuel emissions. But, restoring ecosystems is a step towards saving our world from climate change.