WEF's "One Trillion Trees": good but not enough

The World Economic Forum (WEF) launched a joint global push to conserve, restore and grow one trillion trees worldwide, Thursday 27 August. The initiative, 1t.org, already received support from 26 US-based organizations. This is a welcome initiative, but what is the real potential of reforestation to combat the climate crisis?

Why does it matter? Healthy forests are the fifth most effective nature-based solution to tackle global warming by reducing atmospheric CO2, lowering temperatures, and reducing energy costs, according to drawdown.org. Over the last 30 years, the planet has lost 403 million hectares of tropical forests which count for a third of the world’s forests, playing a key role in climate regulation, according to Global Forest Watch. Only half of the globe’s forests are still intact. If we do not drift from our current track, the global potential canopy cover may shrink by 223 million hectares by 2050.

1t.org. Sensitized by extreme heat and wildfires that are currently devastating California, 26 companies, cities, and organizations across the US have already announced their pledges to the 1t.org platform to help combat adverse effects of climate change. By conserving, restoring, and growing more than 855 million trees — an area equal to 11,331 sq km — this chapter one in the US “shows a significant effort and achievement toward the trillion trees goal,” said the press release.

Leaders and committers. The World Economic Forum and American Forests, supported by the 1t.org US Stakeholder Council, are leading the initiative and will provide tools and technical assistance to bring pledges to life. American Forest Foundation, Bank of America, Mastercard, Microsoft, National Forest Foundation or the cities of Detroit and Dallas are among those who have committed.

How efficient are trees to combat global warming? By soaking up carbon dioxide, trees can help reduce rising temperatures. According to the Intergovernmental Panel on Climate Change (IPCC) an extra billion hectares of trees would reduce CO2 in the atmosphere by 25% and limit the rise to 1.5C by 2050. In 2019, a study from the Crowther Lab in Zurich showed that there is “room for an extra 0.9 billion hectares of canopy cover, which could store 205 gigatons of carbon in areas that would naturally support woodlands and forests”.

Other studies have also shown trees can reduce temperatures by 9 degrees in certain urban heat islands and energy costs by 7.8 billion dollars a year. According to the press release,

“The chance of extreme wildfires occurring also decreases dramatically when forests are managed properly by, for example, planting specially-selected tree species in burned areas and using novel planting techniques.”

Investing in forests also helps improve the economy. According to the WEF, sustainable management of forests would create 230 billion dollars in business opportunities and 16 million jobs worldwide by 2030. From a health perspective, trees absorb 17.4 million tons of air pollutants a year, helping to prevent 670,000 cases of asthma and other acute respiratory symptoms annually.

Misleading potential? There is still no consensus on the best ways to plant these trees effectively. The Crowther Lab’s study has been doomed “scientifically incorrect and dangerously misleading” by certain climate scientists who criticized their methods of calculation of carbon storage potential.

Simply planting more trees is no guarantee of success: it’s not a question of quantity but it requires careful management. Planting trees in the wrong ecosystems can even have a damaging impact. Artificial tree fields, which are economically profitable, should not be confused with forests, which are natural ecosystems. Exploited in rapid rotation, they can even become sources of CO2 rather than sinks.

Last but not least, cutting greenhouse gas emissions, the only long-term and sustainable way to stabilize the climate, remains the highest priority.