Climate activists staged protests yesterday to add pressure on leaders, including US President Barack Obama, to agree on a strong deal to combat global warming at talks this month in Denmark.
Indian Prime Minister Manmohan Singh, whose country is the world's number four greenhouse gas emitter, announced he would attend a closing summit in Copenhagen, joining 104 other leaders including Obama in a sign of growing momentum for a deal.
In the Danish capital, delegates from 190 nations were gathering for the start of the December 7-18 meeting. The biggest UN climate talks in history are aimed at working out a new pact to curb global warming, replacing the 1997 Kyoto Protocol.
Among protests, activists in Berlin, posing as world leaders, sat inside a giant aquarium that was gradually filled with water to highlight the risks of rising sea levels from melting glaciers and ice sheets on Greenland and Antarctica.
About 20,000 people marched in London to protest against global warming before the conference, where senior officials will lay the groundwork for the summit. A Greenpeace demonstration in Paris drew 1,500 people.
"We want the most ambitious deal we can get at the climate change talks," Britain's Energy Secretary Ed Miliband told BBC television from the march.
Denmark welcomed Singh's decision to attend and said that 105 leaders were now due to go.
"India is a key country in the global efforts to tackle climate change," Prime Minister Lars Lokke Rasmussen said in a statement.
"Together these 105 leaders represent 82 per cent of mankind, 89 per cent of the world's GDP and 80 per cent of the world's current emissions."
He added: "If this group of assembled leaders can agree, then their decisions can change the course of the planet."
Obama last Friday dropped plans to stop off in Copenhagen on Wednesday - on his way to Oslo to collect the Nobel Peace Prize - and the White House said he would instead join other world leaders on December 18.
Governments and activists welcomed the switch, which raises pressure for a deal to combat rising emissions that the UN says will cause desertification, mudslides, more powerful cyclones, rising sea levels and species extinctions.
But an agreement is still far off.
China, India, Brazil and South Africa last week rejected a Danish suggestion to set a goal of halving world emissions by 2050, saying rich nations which have burnt fossil fuels since the Industrial Revolution must first slash their own emissions.
Many developing nations at preliminary meetings in Copenhagen yesterday were lining up with the four in opposing the Danish proposals, delegation sources said. China is the top world emitter ahead of the United States, Russia and India.
The UN says rich nations must accept deep cuts in their greenhouse gas emissions by 2020 and come up with at least $10 billion a year in aid to the poor to kick off a deal. It also wants new actions by developing nations to slow the rise of their emissions.