The Amazon rainforest, the planet's last great lung, is increasingly ailing, stripped bare and violated piece by piece. In 2016 deforestation reached record levels; research revealed that between August 2015 and July 2016 almost 8,000 square kilometres of forest were destroyed in Brazil, razed to the ground by loggers, farmers and ranchers.

In an effort to save the world's largest tropical rainforest — and ourselves — the American NGO Conservation International has announced the launch of a new project that, over the next six years, plans to plant 73 million trees, making it the largest tropical reforestation effort in history.

Reforestation focuses on the most vulnerable area

The initiative, which will be led by Conservation International and involves the Brazilian Ministry of the Environment, the Global Environment Facility (Gef), the World Bank, the Brazilian Biodiversity Fund (Funbio) and the Rock in Rio festival, aims to restore greenery to the so-called "arc of deforestation" — the area where nearly half of the world's tropical deforestation occurs.

This vast zone, which stretches across the Brazilian states of Amazonas, Acre, Pará and Rondônia, has been subject to intensive logging and thousands of hectares of rainforest have been cleared to make way for cattle pasture. The first phase of the project aims to restore 70,000 hectares (an area equivalent to approximately 30,000 football pitches) of forest.

The importance of tropical forests: they can absorb more than a third of CO2

"If the world wants to achieve the goal of keeping global temperatures well below two degrees Celsius as set out in the Paris Agreement, then the protection of tropical forests must be non-negotiable," said M. Sanjayan, chief executive of Conservation International. According to him, "it's not just about the trees — you also have to consider what kind of trees: if you truly want to absorb the greatest amount of CO2, tropical forests are the most efficient."

It is estimated that if deforestation were to cease, forests would be capable of absorbing 37 per cent of annual CO2 emissions worldwide. However, biologists fear that 20 per cent of the Amazon rainforest could be deforested over the next two decades, in addition to the 20 per cent that has been felled over the past forty years.

Leggi anche: Ipcc, il rapporto Sr15: "Il mondo rischia di mancare clamorosamente gli obiettivi sul clima"

A new planting technique that is both effective and cost-efficient

For this project, Conservation International will use a new and efficient planting technique, developed in Brazil just a few years ago, called muvuca — a Portuguese word used to describe the presence of many people in a small space. Muvuca involves sowing hundreds of seeds from native tree species of various kinds across every square metre of deforested land; natural selection then allows the most suitable plants to survive and thrive. A study conducted by the FAO revealed that more than 90 per cent of native tree species planted using the muvuca method germinate and are able to survive even drought periods of up to six months.

"With traditional reforestation techniques, an average density of around 160 plants per hectare is achieved," explained Rodrigo Medeiros, vice-president of Conservation International Brazil. "With muvuca, the initial result is 2,500 species per hectare, and after ten years it is possible to reach 5,000 trees per hectare. This system guarantees greater tree cover and is less costly than traditional techniques."

Jair Bolsonaro, the new far-right president, casts doubt on the Paris Agreement

The entire virtuous process of protecting the Amazon rainforest could, however, be called into question by the election of Jair Bolsonaro as president of Brazil. On 25 October, the far-right leader of the South American nation declared that his country would not follow in the footsteps of Donald Trump's United States. Brazil will therefore remain in the Paris Agreement on climate. But only on condition that Brasília is given full sovereignty over the management of the forest. On this point, "they must give me assurances in black and white," the new president stated. Otherwise, a second dramatic withdrawal cannot be ruled out.

Leggi anche: Jair Bolsonaro è il nuovo presidente del Brasile

In Bolsonaro's sights is in particular the "Triple A" project: a hypothetical transnational ecological corridor running from the Andes to the Atlantic Ocean to the Amazon. It envisages the creation of a vast protected zone that could link together national parks, indigenous reserves and biodiversity conservation areas. But according to the new president, in doing so "136 million hectares would no longer be under our jurisdiction." For the Brazilian right, moreover, the forest is far more an economic resource than an indispensable element in saving the planet from climate catastrophe.