Land based climate measures will be essential to limiting global warming, but countries must balance climate action with food production forest protection and biodiversity conservation.
The research conducted by scientists at the Potsdam Institute for Climate Impact Research (PIK), warns that relying mainly on emission cuts in the energy sector while neglecting agriculture forests and other land based solutions could make climate targets significantly more expensive and the goal of limiting warming to 1.5 degrees Celsius by 2100 unattainable.
However, expanding land based climate solutions without careful planning could create competition for agricultural land, increase food prices and put additional pressure on already vulnerable ecosystems.
Combining Bioenergy with Forest Protection Can Reduce Land Pressure
The study examined how countries could use land based measures to reduce greenhouse gas emissions while limiting competition for land.
Researchers considered three major approaches: protecting forests and natural ecosystems to prevent emissions from land-use change, reducing agricultural emissions of methane and nitrous oxide, and expanding biomass based energy production.
The findings show that combining these measures could significantly reduce the amount of land required for energy crops.
Under a scenario limiting peak warming to 1.7 degrees Celsius above pre industrial levels, biomass cultivation could require around 66 million hectares by 2050 if countries also protect and restore ecosystems and reduce agricultural emissions.
However, relying primarily on bioenergy for land based climate mitigation could increase the requirement to 267 million hectares approximately four times as much.
The difference highlights the importance of integrating forest conservation, agricultural emission reductions and bioenergy rather than depending on energy crops alone.
Excluding the Land Sector Could Make Climate Action More Expensive
The study also found that excluding agriculture, forestry and other land use measures from climate strategies could substantially increase the economic cost of achieving climate targets.
For a pathway designed to keep peak warming below 1.7 degrees Celsius, the modelled loss in consumption rises from 1.3 per cent to 3.5 per cent when land-based mitigation measures are excluded. These estimates are compared with a baseline in which current climate policies continue.
According to the researchers without significant reductions in land based greenhouse gas emissions, limiting global warming to 1.5 degrees Celsius by 2100 even after a temporary overshoot, would no longer be achievable in the modelled scenarios.
Competition for Land Could Threaten Food Security
Despite its climate benefits expanding bioenergy production could create serious challenges for agriculture.
Growing crops specifically for energy requires land that could otherwise support food production or natural ecosystems. If more farmland is diverted to energy crops, food production may need to become more intensive on the remaining agricultural land.
The study’s projections also depend partly on future improvements in crop yields. If these improvements fail to materialise, competition for farmland could become more severe and push food prices higher.
The researchers caution that their model does not capture every way in which higher energy costs could affect food prices including expenses related to transportation, processing and marketing.
Global South Could Face a Greater Share of the Burden
The geographical distribution of land-based climate action is another major concern.
The study suggests that under similar or uniform greenhouse gas emission prices across countries a substantial share of land based mitigation could take place in developing nations.
This could increase pressure on food prices in countries where larger sections of the population depend on agriculture for their livelihoods and have fewer resources to cope with rising costs.
Alexander Popp, head of the Land Use Transition Lab at PIK and a co-author of the study, highlighted the concerns associated with this unequal distribution. He noted that much of the potential for land based climate protection lies in the Global South, where food shortages, water scarcity and biodiversity loss are already serious challenges.
The risks extend beyond food security. Large scale energy crop cultivation and afforestation can require substantial land and water resources, potentially affecting biodiversity and natural habitats.
Irrigated bioenergy plantations could further intensify water stress in regions already experiencing shortages.
Researchers also warn that expanding bioenergy without strong land protection policies could trigger land use changes that generate additional greenhouse gas emissions, potentially undermining the climate benefits these projects are intended to deliver.
The study therefore emphasises the need for an integrated approach to climate mitigation one that combines renewable energy and bioenergy with forest conservation, ecosystem restoration and reductions in agricultural emissions while safeguarding food security and natural resources.