If there is a glimmer of light amid the darkness of recent reports from the Brazilian Amazon, where deforestation is accelerating along with threats to the indigenous people who live there, it could lie in the growing power of climate diplomacy, combined with increased understanding of the crucial role played by trees in our planet’s climate system. The deal agreed a month ago between the EU and the Mercosur bloc of Brazil, Argentina, Paraguay and Uruguay (Venezuela is suspended) enhances European leverage with its South American trading partners. Already, the prize of access to EU markets is credited with having convinced Brazil not to follow Donald Trump’s lead by withdrawing from the Paris climate deal. Now the EU must strengthen its environmental commitments, as a letter from 600 scientists demanded before the deal was agreed.

Brazil’s president, Jair Bolsonaro, made no secret of his plans to promote development, and drew powerful support from Brazil’s agribusiness and mining interests before last year’s election. He scorns conservation and indigenous rights, claiming recently that his foreign opponents want Amazon tribes to live “like cavemen”. Satellite data shows the message is getting through, with clearances up sharply and this month set to be the first in five years in which Brazil has lost an area of forest bigger than Greater London. Illegal gold mining too is spreading. Last week one of the leaders of the Waiãpi people, Emyra Waiãpi, was found stabbed to death on a remote reserve in the state of Amapá, after armed men raided his village.