Brazilian President Luiz Inacio Lula da Silva said Thursday that the developed countries must assume their share of the responsibility for the global warming and commit to more ambitious goals of carbon emission reduction.

In his speech at the United Nations Climate Change Conference (COP15) in Copenhagen, President Lula said that many developing countries are contributing to an agreement despite having no resources, and that the developed ones should be doing the same.

The reduction goals must be set according to countries' responsibility for the climate change, he said; it is unacceptable that the least responsible for the change are the first and main victims of the problem.

"The fragilities of some cannot serve as an excuse for the hesitation of others. It is not politically rational or morally justifiable to put corporate interests above the good of humanity," the president stressed.

President Lula reaffirmed Brazil's goal, which is to reduce 36.1 to 38.9 percent of its greenhouse gas emissions by 2020, adding that the measure will cost the government 16 billion U.S. dollars per year.

Lula called for honesty during the conference, saying that the COP15 is not a game in which countries can hide their aces.

"By the end of the match, it may be too late and we will all be losers," he warned.

The president believed that reaching a common ground on the climate change issue is essential not only for environmental protection, but also for economic growth and overcoming social inequalities.

"History's verdict will not spare those who excuse themselves from their responsibilities at this moment," he said.