The project, announced Friday at the “Rock in Rio” music fest in Brazil, aims to restore 73 million trees in the Brazilian Amazon by 2023. “Protecting the Amazon is not something we should think in the future — we have to do it now.” 
 
 The project is a partnership between Conservation International, the Brazilian Ministry of Environment, the Global Environment Facility (GEF), the World Bank, the Brazilian Biodiversity Fund (Funbio) and Rock in Rio’s environmental arm “Amazonia Live.” 
 
 The reforestation effort is part of a broader regional initiative, the Amazonia Sustainable Landscapes Project. According to a press release from Conservation International, the effort will span deforested pasture lands over a 74,000-acre region spanning several Brazilian states—with the greatest focus in Southern Amazonas, Rondônia, Acre, Pará and the Xingu watershed. “It is a carefully controlled experiment to literally figure out how to do tropical restoration at scale, so that people can replicate it and we can drive the costs down dramatically.” 
 
 Over the past 40 years, about 20% of the Amazon has been cut down or destroyed, and scientists worry that another 20% of the rainforest will be lost in the next couple of decades. “If the world is to hit the 1.2°C or 2°C [degrees of warming] target that we all agreed to in Paris, then protecting tropical forests in particular has to be a big part of that,” M. Sanjayan, CEO of Conservation International, tells Fast Company. “The fate of the Amazon depends on getting this right — as do the region’s 25 million residents, its countless species and the climate of our planet.” 
 
 The Amazon forest is home to the richest biodiversity of any ecosystem on the planet — a recent report described some 400 new species discovered in the Amazon between 2014 and 2015 alone — yet is rapidly vanishing with increasing global demand for resources. In this latest effort, the restorationists are trying a new method called muvuca, in which they will spread the seeds of native trees across the slash and burned land and animal pastures. “With plant-by-plant reforestation techniques, you get a typical density of about 160 plants per hectare,” Rodrigo Medeiros, vice president of Conservation International’s Brazil program, tells Townsend. “With muvuca, the initial outcome is 2,500 [trees] per hectare. If you’re really thinking about getting carbon dioxide out of atmosphere, then tropical forests are the ones that end up mattering the most.” 
 
 He’s right: Simply stopping deforestation could allow existing forests to absorb up to 37% of our annual carbon emissions; replenishing degraded areas could do significantly more for the planet.
– The Amazon rainforest's "arc of deforestation" could soon have 73 million new trees. In an effort to reseed 74,000 acres of the Amazon—20% of which has been destroyed in the last 40 years—Conservation International, the World Bank, Brazil's environmental ministry, and several other groups are working together to spread seeds in the Amazonas, Acre, Pará, Rondonia, and Xingu areas of Brazil, reports Fast Company. Reforestation normally involves saplings, which must be grown and planted. But Conservation International CEO M. Sanjayan hopes dropping seeds from 200 native species per square meter of land, in what is known as the muvuca strategy, will "drive the costs down dramatically" and produce a greater diversity and density of plants. "If you're really thinking about getting carbon dioxide out of [the] atmosphere, then tropical forests are the ones that end up mattering the most," says Sanjayan, noting the move will help Brazil reach its Paris Accord target of reforesting an area the size of Pennsylvania by 2030, per Smithsonian. A release notes it's the "largest tropical forest restoration in the world." Up to 2,000 locals will work together to seed each hectare, with families receiving $700 per hectare. Additional seeds will also be distributed in existing forested areas. Some 90% of seeds are expected to germinate, though only the strongest will survive. A leader of the program predicts there will be 2,500 trees per hectare after six years and up to 5,000 after 10 years. (Deforestation has revealed millennia-old "geoglyphs" in Brazil.)