Temperature overshoot responses to ambitious forestation in an Earth System Model

Area of Science:

• Climate Science
• Ecology
• Environmental Science

Background:

• Global temperature overshoot is a growing concern.
• Country pledges for Afforestation/Reforestation (A/R) are ambitious.
• The Earth system response to large-scale A/R under high overshoot scenarios is not well understood.

Purpose of the Study:

• To assess the mitigation potential of ambitious A/R scenarios.
• To understand Earth system responses to large-scale A/R under high overshoot.
• To evaluate A/R as a climate mitigation tool alongside emission reductions.

Main Methods:

• Developed an ambitious A/R scenario using 1259 Integrated Assessment Model scenarios, restoration potential maps, and biodiversity constraints.
• Simulated the scenario using the Max Planck Institute's Earth System Model.
• Quantified temperature reductions and changes in overshoot duration.

Main Results:

• The ambitious A/R scenario reached 595 Mha by 2060 and 935 Mha by 2100.
• Peak temperature was reduced by 0.08°C.
• End-of-century temperature was reduced by 0.2°C, and overshoot duration decreased by 13 years.

Conclusions:

• Global A/R, consistent with country pledges, can be a valuable mitigation tool in overshoot scenarios.
• A/R complements fossil fuel emission reductions.
• Socio-ecological implications of large-scale A/R must be carefully scrutinized to avoid adverse side effects.