Keeping global warming beneath 1.5 degrees Celsius presents a significant challenge. Reaching this target necessitates not just drastic cuts in greenhouse gas emissions tied to human activities but also an extensive reallocation of land resources. This shift is essential to meet the increasing demands for bioenergy and to harness nature-based solutions for carbon sequestration while simultaneously ensuring that there is adequate land for food production and maintaining ecosystem integrity.
The evolving role of land in a world striving for the 1.5°C threshold encompasses two main objectives: removing carbon dioxide from the atmosphere and generating clean energy. Strategies for land-based carbon dioxide removal include bioenergy combined with carbon capture and storage, direct air capture, and approaches such as afforestation and reforestation alongside various nature-based solutions. Clean energy production is further diversified through wind and solar farms and sustainable bioenergy agriculture. Any land-use decisions aimed at climate mitigation must also carefully balance competing priorities like food security and ecosystem health.
The range of land-based climate mitigation options varies significantly regarding costs—considering land requirements, implications for food security, impacts on biodiversity, and other ecosystem services—as well as the associated benefits, such as the potential for greenhouse gas sequestration and clean energy generation.
A recent study published in the journal Frontiers in Environmental Science represents the most extensive evaluation thus far of competing land-use strategies and technology options needed to restrain global warming to 1.5°C. Conducted by researchers from the MIT Center for Sustainability Science and Strategy (CS3), this study employs the MIT Integrated Global System Modeling (IGSM) framework to assess both the costs and benefits of various land-based climate mitigation avenues outlined in Sky2050, a climate stabilization scenario aimed at achieving the 1.5°C objective as developed by Shell.
According to this scenario, the demand for bioenergy and natural carbon sinks is projected to grow in tandem with the need for sustainable agriculture and food production. To assess the feasibility of accommodating these demands, the research team utilizes the global hectare (gha)—representing an area of 10,000 square meters, or roughly 2.471 acres—as the standard measurement. Current estimates indicate that the Earth’s habitable land area totals about 10 gha, with 5 gha currently allocated for food production and bioenergy sources.
The findings reveal that with transformative shifts in policy, land management practices, and consumption behaviors, global land resources can indeed meet the sustainable food supply and ecosystem service demands for this century while concurrently lowering greenhouse gas emissions in line with the 1.5°C target. Such transformative adjustments would entail policies aimed at preserving natural ecosystems, halting deforestation, accelerating reforestation and afforestation, advancing sustainable agricultural practices, curbing food waste, and encouraging consumer support for sustainably produced products.
Should these transformative changes be executed, approximately 2.5 to 3.5 gha of land would be employed for nature-based solutions capable of sequestering between 3 to 6 gigatonnes (Gt) of CO2 each year. An additional 0.4 to 0.6 gha would be allocated for energy production, specifically with 0.2 to 0.3 gha targeted for bioenergy and 0.2 to 0.35 gha for wind and solar energy generation.
As CS3 Principal Research Scientist Angelo Gurgel, lead author of the study, remarks, “Our findings indicate that sufficient land exists to support a future aligning with the 1.5°C goal, provided that robust policies are enacted at both national and global levels. These policies should foster effective land use for food, energy, and nature and necessitate long-term commitments from government and industry leaders.”
Photo credit & article inspired by: Massachusetts Institute of Technology
