Could we significantly reduce atmospheric CO2 by planting more trees?
Scientists have established that reforestation can help mitigate climate change by sequestering atmospheric carbon dioxide.
A Science study published in 2019 on global reforestation potential found that ecosystems could support a 25% increase in forested area. That increase could store a quarter of the current atmospheric carbon pool.
In response to critical comments on the study, Science clarified that "tree restoration should [not] be considered the unique solution to climate change" and acknowledged "the urgent need to reduce greenhouse gas emissions from the combustion of fossil fuels."
There is not enough reforestation potential to sequester the CO2 necessary to keep global warming below two degrees Celsius: a 2017 study found that trees could sequester a third of what's needed. Trees also do not prevent CO2 from being absorbed into the oceans. CO2 acidifies water, disrupting marine ecosystems.