Is There Enough Land to Fight Climate Change and Feed the World?

Limiting global warming to 1.5°C is a challenging task. Reaching this target will require not only a significant reduction in greenhouse gas emissions from human activities but also a major reorganization of land use to support these efforts and maintain the biosphere, including human populations. More land will be necessary to meet the rising demand for bioenergy and nature-based carbon sequestration, while also ensuring enough space for food production and ecological balance.

The Dual Role of Land in a 1.5°C World

In a 1.5°C future, land will play a dual role: removing carbon dioxide from the atmosphere and producing clean energy. Land-based carbon dioxide removal methods include bioenergy with carbon capture and storage, direct air capture, and afforestation/reforestation, along with other nature-based solutions. Clean energy production from land involves wind and solar farms, as well as sustainable bioenergy crops. Any decision to allocate more land for climate mitigation must also consider competing needs for food security and ecosystem health.

The choices for land-based climate mitigation vary in cost—such as the land area needed, effects on food security, and impacts on biodiversity and ecosystem services—and in benefits, including their potential for sequestering greenhouse gases and generating clean energy.

A recent study published in Frontiers in Environmental Science offers the most detailed analysis to date of land-use and technology options for limiting global warming to 1.5°C.

MIT Researchers Explore Land-Based Strategies for a 1.5°C Future

Led by researchers from the MIT Center for Sustainability Science and Strategy (CS3), the study uses the MIT Integrated Global System Modeling (IGSM) framework to assess the costs and benefits of various land-based climate mitigation strategies in the Sky2050 scenario, a 1.5°C climate-stabilization model developed by Shell.

In this scenario, the demand for bioenergy and natural carbon sinks increases, alongside the need for sustainable farming and food production. To determine whether there’s enough land to meet these growing needs, the researchers use the global hectare (gha)—a unit of measurement representing 10,000 square meters (or 2.471 acres)—and current estimates of the Earth’s habitable land area (around 10 gha) and land used for food production and bioenergy (5 gha).

The study finds that, with transformative changes in policy, land management, and consumption patterns, global land can sustainably supply food and ecosystem services throughout the century while also reducing greenhouse gas emissions to meet the 1.5°C target.

Transformative Policies for Sustainable Land Use

These changes include policies to protect natural ecosystems, halt deforestation, accelerate reforestation and afforestation, promote sustainable agricultural technologies and practices, reduce food and agricultural waste, and incentivize consumers to buy sustainably produced goods.

If these changes are implemented, 2.5–3.5 gha of land could be dedicated to nature-based solutions (NBS) to sequester 3–6 gigatons (Gt) of CO₂ annually. Additionally, 0.4–0.6 gha would be allocated for energy production, split between 0.2–0.3 gha for bioenergy and 0.2–0.35 gha for wind and solar power.

“Our scenario demonstrates that sufficient land exists to support a 1.5°C future, provided effective national and global policies are in place,” says CS3 Principal Research Scientist Angelo Gurgel, the study’s lead author. “These policies must promote efficient land use for food, energy, and nature while being backed by long-term commitments from governments and industry leaders.”

Read the original article on: Phys Org

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