Guy Edwards, a Latin America expert and co-director of the Climate and Development Lab at Brown University, said Brazil’s decision to back out of hosting the summit is unwise in economic terms, since it would mean the country would forgo any investment, business deals and cooperation agreements to advance low carbon growth at the time when Brazil needs an economic boost.

“The irony of the incoming Bolsonaro administration’s decision to cancel the conference is that it will forgo the potentially hefty levels of investment and any number of business deals and cooperation agreements to advance low carbon growth just at the time that Brazil needs an economic boost,” he said.

Manuel Pulgar-Vidal, the former environment minister of Peru, called Brazil’s decision “a bit sad,” and added that it also creates a logistical hurdle for next year’s climate change discussions.

Under the United Nations system, a country from Latin America is supposed to host the summit in 2019. Brazil was the only country in the region to volunteer for the task, which can cost a country as much as $100 million.

Other countries in the region still have time to step in, but it is unclear which might do so. Argentina has held climate summits in the past, but it is hosting this week’s Group of 20 talks and may not want to incur another large expense. Mr. Pulgar-Vidal said it is unlikely that Peru, which spent $72 million to host a climate summit in 2014, would do it again.