Amazon experiment to gauge impact of climate change on rainforest

Open-air laboratory will allow scientists to understand how the rainforest will behave in different scenarios

One of the towers being set up in Brazil's Amazon jungle to predict how rainforests will react to higher carbon dioxide levels. EPA

Deep in the Amazon, an experiment is unfolding to evaluate what will happen to the world's largest rainforest when carbon dioxide levels rise.

The AmazonFace project, financed by Brazil and the UK, is “an open-air laboratory that will allow us to understand how the rainforest will behave in future climate change scenarios”, says Carlos Quesada, one of the co-ordinators.

Mr Quesada stands at the foot of a soaring metal tower that protrudes through the rainforest canopy at a site 80km north of Manaus in north-west Brazil.

Sixteen other towers arranged in a circle around it will “pump” carbon dioxide into the ring, replicating levels that may occur with global warming.

“How will the rainforest react to the rising temperature, the reduction in water availability, in a world with more carbon in the atmosphere?” asks Mr Quesada, a researcher at an Amazon research institute that is part of the Brazilian Ministry of Science and Technology.

The technology known as Face (Free Air CO2 Enrichment) has already been used to study the impact on forests in Australia, the US and the UK, but never in a tropical rainforest.

By 2024, there will be six “carbon rings” pumping carbon dioxide, one of the causes of global warming, at a concentration that is 40 per cent to 50 per cent higher than today.

Over a decade, researchers will analyse the processes occurring in leaves, roots, soil, water and nutrient cycles.

“We will have more accurate projections on how the Amazon rainforest can help combat climate change with its ability to absorb carbon from the atmosphere. Also, it will help us understand how the rainforest will be impacted by these changes,” says David Lapola, a researcher at the University of Campinas, who co-ordinates the project with Mr Quesada.

The carbon dioxide increase in the atmosphere may lead to the creation of grassy plains, or savannah, where the Amazon rainforest once flourished, with vegetation better adapted to higher temperatures and longer droughts.

But carbon dioxide could also “fertilise” the forest and make it temporarily more resistant to these changes.

“This is a positive scenario, at least for a short time, a period for us to get to zero-emission policies, to keep temperature increases to only 1.5ºC,” Mr Quesada says.

The project “is a window to the future”, he says.

“You open the window and look at what might be happening 30 years ahead.”

The UN's Intergovernmental Panel on Climate Change has called for ambitious action to counter global warming again this year.

According to its latest report in March, global warming will surpass 1.5ºC in the decades after 2030, leading to irreversible loss of ecosystems.

Coinciding with global warming is the impact of human deforestation in the Amazon.

A 2018 study by scientists Thomas Lovejoy and Carlos Nobre found that the Amazon is hurtling towards a tipping point where savannahs begin to replace rainforest.

They said that would happen with deforestation of 20 per cent to 25 per cent of Amazon territory. Currently, deforestation stands at 15 per cent.

AmazonFace, co-ordinated by the University of Campinas and the Brazilian Ministry of Science, has the support of the Foreign Office and the British Meteorological Service.

British Foreign Secretary James Cleverly visited the site this week and announced a new contribution of £2 million ($2.4 million) to the project. The UK has given £7.3 million to the project since 2021.

Brazil, for its part, has invested 32 million reais ($6.4 million).