World leaders met at the United Nations headquarters in New York on Monday for a one-day conference on climate change and agreed that industrialized nations must lead the fight against global warming.

Developed countries pledged to concentrate on cleaner energy sources and radical changes in the industrial sector, all these measures being aimed at curbing the emissions of greenhouse gases. But other countries that are struggling to implement economic reforms, said climate change has already affected them and asked for logistic and financial aid.

Monday’s conference represented a “historic” event and provided firm solutions that would be analyzed and approved at the forthcoming summit held in Bali, Indonesia, UN Secretary General Ban Ki-moon said.

During the December meeting, world leaders will negotiate a new agreement that would replace the Kyoto Protocol. The treaty which sets binding targets for developed economies to cut greenhouse gas emissions will expire in 2012 and a replacement is being discussed.

“I heard a clear call from world leaders for a breakthrough on climate change in Bali,” the South Korean diplomat said in front of the UN General Assembly at the close of the meeting, which gathered leaders from 150 countries.

“This event has sent a powerful signal to the world ... that there is a will and determination at the highest level to break with the past and act decisively,” Ban said.

Ban welcomed the attitude of some countries with powerful industries that vowed to head this battle with climate change on all fronts.  

French President Nicolas Sarkozy said economies should develop in a clean manner and all countries must be aware of the threat represented by global warming.

“It is not a question of choice between growth and protecting our world. We need clean growth. A new economy must be invented,” Sarkozy said.

Sarkozy made a call to the world's major polluters to significantly slash the emissions of greenhouse gases in the following years. He also said nuclear energy represents a viable solution, citing his country’s example.

US President George W Bush didn’t attend the conference, his place being taken by Secretary of State Condoleezza Rice who said state-of-the-art technologies are the main weapon of the United States in the battle with climate change.

She said “the world needs a technological revolution” and alternative power sources must be developed in order to “transcend” fossil fuels.

The European Union imposed several targets for its member states, aiming to reduce carbon emissions by 20 per cent from 1990 levels by 2020. However, German Chancellor Angela Merkel and European Commission President Jose Manuel Barroso said the target could be lifted to 30 per cent if an international agreement comprising other regions comes into effect.

According to recent reports of the Intergovernmental Panel on Climate Change (IPCC), global warming is without any doubt the result of human activity and some regions on the globe have already been affected.

“Those who contributed least to what is happening ... are bearing the brunt of it,” Ban Ki-moon said.

Ban’s statement was anchored by some developing nations, that said powerful economies should help them reduce growing carbon emissions. The UN head said every country has its own means of fighting climate change and governments should be “creative” when searching for solutions to reducing pollution.