One paper says that financial incentives to plant trees can backfire and reduce biodiversity with little impact on carbon emissions. A separate project found that the amount of carbon that new forests can absorb may be overestimated. The key message from both papers is that planting trees is not a simple climate solution. Over the past few years, the idea of planting trees as a low cost, high impact solution to climate change has really taken hold.
Previous studies have indicated that trees have enormous potential to soak up and store carbon, and many countries have established tree planting campaigns as a key element of their plans to tackle climate change. In the UK, promises by the political parties to plant ever larger numbers of trees were a feature of last year’s general election. In the US, even President Donald Trump has rowed in behind the Trillion Trees Campaign.
So far, around 40 nations have endorsed the idea. But scientists have urged caution against the headlong rush to plant new forests. They point to the fact that in the Bonn Challenge nearly 80% of the commitments made to date involve planting monoculture plantations or a limited mix of trees that produce specific products such as fruit or rubber. The authors of this new study have looked closely at the financial incentives given to private landowners to plant trees. The authors say that previous assumptions about how much organic carbon can be fixed by planting new trees is likely an overestimate. “We hope that people can understand that afforestation practices are not one single thing,” said Dr Anping Chen, from Colorado State University and a lead author on the study. “Afforestation involves many technical details and balances of different parts, and it cannot solve all our climate problems.”
Source: BBC
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