Brazil presents itself as part of the solution, but critics see a climate scofflaw.

RIO DE JANEIRO — Brazil, a global climate leader turned environmental offender under President Jair Bolsonaro, approached the United Nations climate conference in Glasgow ready to prove that it was changing course, with commitments to create green jobs, cut carbon emissions and curb deforestation.

But even as John Kerry, the U.S. climate envoy, said on Twitter that those steps added “crucial momentum” to addressing climate change, environmentalists said the plans lacked the scope and detail to make them credible. And Mr. Bolsonaro’s absence from the summit raised questions about his commitment to the reversal.

Days before the conference, Brazil’s government announced a policy to create green jobs while preserving the country’s vast forests. Then, on Monday, Brazil committed to cutting carbon emissions in half by 2030, achieving carbon neutrality by 2050 and ending illegal deforestation by 2028.

Yet environmentalists and political opponents in Brazil were quick to poke holes in the announcements. The green growth plan lacked details to make it credible, they said, and the commitment on emissions is essentially unchanged from the one Brazil made in 2015.

Then there is Brazil’s track record. By law, the country was supposed to have already started slashing its emissions. Instead, Brazil is one of the few nations where emissions rose during the pandemic, an increase that was largely driven by a surge in deforestation.

From August 2020 to July 2021, Brazil’s portion of the Amazon lost 4,200 square miles of tree cover, according to the latest numbers published by the National Institute of Space Research.