A renewed pledge from participants at ongoing U.N. climate talks in Warsaw, Poland, to cut carbon emissions remains elusive, the Associated Press reports.
As negotiators head into the final week of the conference, participating nations have not yet promised to up existing commitments to reduce greenhouse-gas emissions.
Instead, Japan said Friday that it would no longer be able to meet its goal of cutting emissions by 25 percent from 1990 levels as it looks to fossil fuels to supply energy while it transitions away from nuclear power.
Australian Prime Minister Tony Abbott is also pushing to repeal a tax on carbon, a move that environmental advocates say will make it extremely difficult for the country to cut emissions.
The announcements have drawn criticism from delegates who say that wealthier nations should be leading the charge against climate change.
"We need to be very concerned with individual actions of developed countries that are backtracking [on] their commitments," said Jose Marcondes de Carvalho, an envoy from Brazil.