BRASILIA (Reuters) - Brazil may have backed out of hosting this year's U.N. climate summit, but the country will still take a leading role in negotiating the mechanisms needed to implement the Paris Agreement, its top climate negotiator said on Tuesday.

Shortly after right-wing President Jair Bolsonaro won election last year, he canceled Brazil's plans to host the COP25 climate change conference. The summit will now be held in Chile in December.

At the meeting, countries will attempt to settle final details on how to implement the landmark 2015 Paris Agreement, which aims to hold global warming to 1.5 degrees to 2 degrees Celsius to avert the worst affects of climate change.

Leonardo Cleaver de Athayde, the lead climate negotiator in Brazil's Foreign Ministry, told a congressional hearing that Brazil would be a protagonist on many of the key points of negotiation, including rules for carbon markets and financing for developing countries.

Athayde said that developed countries should remember that they played a larger role in causing climate change and therefore should take more responsibility in resolving it.

"The recognition of the historic responsibility of developed countries and more industrialized nations for greenhouse gas emissions is a central aspect of the climate regime and always has been," he said.

He warned developed countries not to forget commitments made prior to the Paris accord, noting that the promise to mobilize $100 billion in annual financing to support developing countries' climate initiatives by 2020 had yet to materialize.

"There is essentially one major challenge the climate regime is facing and will continue to face in the years to come," he said. "We have sensed that unfortunately there is a tendency on the part of many players ... to act as if after the Paris Agreement everything that came before it ceases to exist."

Brazil has laid out ambitious targets for greenhouse gas reductions under the Paris Agreement, pledging to cut emissions by 37% by 2025, compared to 2005 levels, with a looser commitment to raise that to 43% by 2030.

Bolsonaro said on the campaign trail last year that the country would pull out of the Paris Agreement but later backtracked. Athayde confirmed that the country's targets remain unchanged under the new Bolsonaro government.

Bolsonaro has nevertheless appointed climate skeptics to key positions, such as Foreign Minister Ernesto Araujo, who argues that global warming is a Marxist hoax.

Page: WTVB