Andy Lester, Head of Conservation, probes the recent study on the potential of global tree restoration as one of the best solutions for climate change.
In a report earlier this month, several scientists announced that up to two thirds of current CO2 emissions could be mopped up if we plant one trillion trees globally. British scientist Tom Crowther boldly proclaims, ‘It’s a solution that doesn’t require Donald Trump to immediately start believing in climate change. Every one of us can get involved by growing trees themselves, donating to forest restoration organisations and avoiding irresponsible companies.’ Is it really that simple?
The answer is – as is often the case – yes and no. Yes, trees can make a huge and significant difference. Trees are the largest land-based supplier of oxygen and one of the most substantial global ‘sinks’ (storage) for carbon.
But it is not quite that easy. Not all trees have a net benefit for nature or a long-term benefit for the planet. The government in Ireland, for example, is actively promoting reforestation and planting an area the size of Dublin every year. But the majority of the trees being planted are not native mixed forest but Sitka spruce from Alaska. This conifer thrives in the damp, mild climate, grows fast and has numerous forestry uses. However, they are dire for wildlife, creating an acidic blanket of needles that suppresses vegetation and prevents birds from nesting and insects from feeding.
So what is the solution? In short, there needs to be a concerted global effort to re-forest the planet with native tree species; in areas where climate change is rapid, this needs to be with species that are either drought- or flood-resistant. Nowhere is this more successful than in Costa Rica, where the government is working with landowners and big business to reach a 60% target of forest cover by 2050 (most of it native). The advantage of the Costa Rican model is that it locks in more carbon for longer and increases wildlife, which plays a substantial role in spreading seeds to new areas and naturally regenerating additional forest areas, in turn reducing the cost of replanting.
In the UK, woodland cover currently stands at 13%, with much variation between England, Wales, Scotland and Northern Ireland. To keep the UK on track for net zero emissions, an ambitious 17% woodland tree cover target by 2050 must be realised. Latest statistics from The Forestry Commission stress the challenges faced: just 1,420 hectares of woodland was created, against the government’s aspirational target of 5,000 in the period January – March 2019 in England.
Despite the urgency to increase afforestation efforts, as well as Tom Crowther’s very valid point to get out there and plant trees, we shouldn’t fall into the trap of planting just any trees. We need to choose wisely and take into account the needs of wildlife as well as the needs of people to ensure the most sustainable future for all. Even less should we fall into the disastrous trap of believing that tree planting is a get out of jail free card: we still need to proceed urgently to cut our greenhouse gas emissions in the first place, by getting off fossil fuels fast, changing our diets, and stopping rampant tropical deforestation.