Over 100 world leaders have pledged more than $19bn to halt and reverse deforestation by 2030 in the first major agreement at COP26.

Boris Johnson celebrated the “landmark commitment” to protect “the lungs of our planet”, saying: “Let’s end this great global chainsaw massacre”.

Countries to sign the pledge cover around 85 per cent of our forests globally. Key signatories include China, Indonesia – the world’s largest exporter of palm oil –  and Russia, which contains more than one fifth of the planet’s trees.

Perhaps most crucially of all, Brazil – which houses two thirds of the Amazon – has signed the deal. This comes after deforestation in the Amazon accelerated to a 12-year high in 2020. 

Why is curbing deforestation so vital? 

Forests are one of our primary defences against a warming world. They regulate ecosystems and are an enormous carbon store. Approximately 2.6 billion tonnes of carbon dioxide – one-third of the CO2 released from burning fossil fuels – is absorbed by forests every year.

Yet according to current estimates, an area of forest the size of 27 football pitches is destroyed every minute. 

Usually this human-driven removal of trees is done to convert land into space suitable for growing commercially valuable agricultural products: in Brazil, large parts of the Amazon have been cut down for beef production, while many Indonesian forests have been cleared for palm oil plantations. 

Human land-clearing accounts for almost a quarter of greenhouse gas emissions. Deforestation also threatens to drive numerous species to extinction: almost two thirds of Earth’s species live solely in forests. 

Protecting forests is paramount. But how easy will it be to tackle deforestation in practice? 

It’s worth noting that we already have a model example: Costa Rica is the only tropical country to have successfully reversed what was once one of the highest deforestation rates in Latin America and to regrow large expanses of forest. This is in large part down to a conservation scheme called “payments for environmental services” which financially rewards landowners for protecting forests and biodiversity.

Indonesia has also managed to slow deforestation in recent years thanks to a palm oil expansion moratorium, although some experts warn that this measure is fragile because, unlike in Costa Rica, the economic incentive to cut down forest remains.

Reforestation is a significant part of the COP deal. One issue is choosing what type of trees to plant: should the priority be choosing a tree species which is fast growing and absorbs the most carbon or a native species to preserve biological diversity?

Fast-growing trees like teak and eucalyptus are often used for reforestation, but many NGOs warn that relying on monocultures is unsustainable, and the use of non-native plants has adverse effects on the surrounding environment. 

Ireland, Europe’s least forested country, is a case in point. The Irish government offers landowners generous grants to plant fast-growing trees such as Sitka spruce. Yet dense blocks of non-native coniferous trees replacing once nature-rich farmland is driving out endogenous wildlife such as hen harriers and curlews. 

Others are sceptical about whether this new deforestation deal will have any real impact because a similar pledge made in 2014, signed by 40 governments, came nowhere close to meeting its target of halving deforestation by 2020. 

But it could be different this time. Big players like Brazil, Russia, China didn’t sign up in 2014. 

Ana Yang, executive director at Chatham House Sustainability Accelerator, sums it up nicely: “This deal involves more countries, more players and more money. But the devil is in the detail which we still need to see.”