[Science] Arctic and Amazon climate tipping points put our future in doubt – AI

The policies of Brazil’s president, Jair Bolsonaro, have seen an increase in Amazon burningEvaristo Sa/AFP/Getty Images YOU rock your chair back, confident you are still in control and can restore equilibrium. Before you know it, you are on the floor, struck by an irreversible change you can’t swing back from. That’s the dangerous thing about tipping points: you don’t know you have reached one until it is too late. Earth’s climate could now be facing at least two. Reports from Brazil’s National Institute for Space Research suggest that wildfires in the Amazon are occurring in unusually high numbers (see “Record Amazon rainforest fires spark row between Brazil and France“). They haven’t yet been confirmed as record-breaking, but many see them as evidence that the anti-environment, pro-agriculture policies of Brazil’s president, Jair Bolsonaro, are driving illegal burning of the rainforest. Advertisement This is disastrous for the people and wildlife living there, and for the planet. The Amazon is a region of extraordinary cultural and biological diversity, and a huge global sink of carbon dioxide. We need it to have a chance of keeping global warming to a manageable level. Fewer trees means less water vapour being pumped into the atmosphere. Intact regions of forest start to suffer. At some point, the whole may reach a tipping point where the untouched forest dies and the Amazon flips to become a non-forest ecosystem. We don’t know where that point is. Some studies indicate that we could get there if a fifth of the rainforest is lost. Others suggest a tipping point could be reached as soon as 2030. Meanwhile, an unprecedented number of fires are ripping through the Arctic (see “The pyrocene has begun: How to tackle a world of raging wildfires“). There, the tipping point is of a different nature: a sea-ice-free Arctic creating positive feedbacks that accelerate warming. That risk is now so dire that some researchers say we should investigate local geoengineering options to prevent it (see “Refreezing the Arctic: How to bring the ice back with geoengineering“). The law of unintended consequences means that must be a last resort. As for the Amazon, Bolsonaro must be persuaded to about-face, if necessary by withholding aid and trade deals. We know by now what we all have to do. Let’s not test the tipping points. More on these topics: climate change forest fires