For the first time, an international team of scientists have calculated the total land area that the countries of the world have included in their individual plans for climate action, known as nationally determined contributions. The results show a big divide between the countries' expected land use and the actual potential of land to mitigate climate change.

“By totalling the aggregate land area that countries want to use to reach net zero emissions, our study shows how unrealistic the NDCs are. If fully implemented, the plans will affect land currently used for other purposes. This would create major conflicts around food production and biodiversity,” says Wim Carton, senior lecturer at Lund University.

Every five years, countries that support the Paris Agreement produce nationally determined contributions, NDCs, which set out their plans for action on climate change. While not legally binding, the NDCs can be seen as an indication of how different countries plan to meet their climate change mitigation and adaptation targets.

The research study, published in Nature Communications, calculates the total amount of land that would be taken up if the countries' climate plans are implemented. In total, the researchers reviewed 194 different NDCs and were able to convert land strategies into hectares for 140 countries.

Forests to sequester carbon dioxide
Under the plans, a large part of the land in question, 40%, will be converted to forest to store carbon dioxide (as the forest grows, carbon dioxide is absorbed from the atmosphere and sequestered by the trees). The remaining land area includes ecosystem restoration, land and forest restoration, and for a few countries, projects to capture and store carbon in various ways.

“While we will probably need to capture and store carbon in the future to reach net-zero emissions, we clearly need to stop relying so heavily on tree planting and bioenergy crops. Otherwise, we will exacerbate the problems we already have with high-intensity agriculture and unsustainable land use.”

Above all, countries need to have more realistic expectations about the role that land can play. Existing scenarios are unlikely to work, and if they do, there would be catastrophic consequences for livelihoods, ecosystems and biodiversity. They also distract from actions that need to be taken here and now to reduce emissions.

Major users of fossil fuels put their hopes in land
Some NDCs stand out more than others, say researchers. For example, a number of countries in sub-Saharan Africa are committing to using more than a fifth of their land area to reach net zero emissions. If implemented, this would result in already vulnerable and poor people losing access to land they need to survive.

But even large-scale fossil fuel users are planning to use a lot of land to meet their climate targets.

“The countries that emit the most seem to want to continue business as usual. Instead of stepping up their efforts to reduce emissions, they foresee a future where they simply offset any emissions by removing carbon on a large scale.”