imgAfforestationIcon Afforestation

Plant new forests and restore old forests. As trees grow, they draw carbon out of the air, which reduces the concentration of carbon dioxide. However, without care, large-scale afforestation can compromise biodiversity and historical land rights.


  • Government policies, incentives, and funding to identify available land, plant trees, and manage forests.
  • Business, land owner, and public support for large scale tree planting.

Big Message

  • Afforestation has the potential to pull significant amounts of carbon dioxide out of the atmosphere, but land availability and other effects should be considered.

Key Dynamics

  • Growing more trees boosts global removal of CO2 from the atmosphere. Photosynthesis pulls carbon into biomass and soils. Watch the temperature decrease modestly as a result.
  • Explore the graph “Land for Carbon Dioxide Removal”. The land mass of India is 300 million hectares, so if we were to forest an area of that size we would still not see much change in temperature.

Potential Co-Benefits of Increasing Afforestation

  • New forests can create new ecosystems and protect existing wildlife habitats, biodiversity, and ecosystem services.
  • Larger and healthier tree canopies in cities reduce urban heat island effects and energy needed for heating and cooling.
  • Jobs are created in tree planting, care, and maintenance.

Equity Considerations

  • Afforestation entails shifting large areas of land into forests. This can sometimes result in monocultures of trees that are all the same ages, which is not as helpful to biodiversity or providing people sustainable livelihoods as natural forests.
  • Large shifts in land can compromise historic land access, so involving low-income and minority communities, including Indigenous peoples, in the process of funding, design, implementation, and job training is essential.

Slider Settings

status quo low growth medium growth high growth
Percent available land for afforestation 0% to +15% +15% to +40% +40% to +70% +70% to +100%

Model Structure

The input changes total or gross carbon removal from trees and plants through photosynthesis. The carbon sequestration of forests changes over time as the forest matures. Notice that net carbon removals are different than total removals due to carbon loss in older or unhealthy forests.

The default settings for the maximum potential of afforestation (“% of max potential”) are sourced from the low range of the 2018 ‘Greenhouse gas removal’ report by the Royal Society (Table 2, chapter 2). For example, moving the simulator’s afforestation slider to “100% of max potential” increases removals up to 4 Gton/yr. This value was taken from the report’s range of 3-20 Gton/yr, accounting for afforestation and reforestation, in combination with the added value 1-2 Gton/yr due to forest management.

For higher removal, one can adjust the “Afforestation settings” within the “Assumptions” view.