DOHA, Qatar -- Pointing to the destruction caused by Hurricane Sandy and other weather disasters this year, U.N. Secretary-General Ban Ki-moon told an international climate conference Tuesday that it was time to "prove wrong" those who still have doubts about global warming.
Ban, addressing delegates at the annual U.N. climate talks, said time is running out for governments to act, citing recent reports showing rising emissions of greenhouse gases, which most scientists say are causing the warming trend.
"The abnormal is the new normal," Ban told environment ministers and climate officials from nearly 200 countries. "This year we have seen Manhattan and Beijing under water, hundreds of thousands of people washed from their homes in Colombia, Peru, the Philippines, Australia."
"The danger signs are all around," he said, noting that ice caps are melting, permafrost thawing and sea levels rising.
Delegates at the two-week talks that are set to end Friday are discussing future emissions cuts and climate aid to poor countries, issues that rich nations and the developing world have struggled to agree on for years.
In Doha, developing countries have criticized richer nations for not promising higher emissions cuts and not giving any firm commitments on how they plan to scale up climate aid to $100 billion by 2020, a pledge they made three years ago.
Ban told reporters after his speech that richer countries, including the U.S., "should take leadership" on climate change because they have the resources and technology to address the problem.
On Tuesday, Britain announced two initiatives to support renewable energy in Africa and a water management program that it said would help 18 million poor people become more resilient to climate change. The initiatives, totaling 133 million pounds ($214 million) over the next three years, were welcomed by climate activists.
"At last, a developed country has finally made a pledge for future climate finance here in Doha," Oxfam Climate Change Policy Advisor Tracy Carty said, but noted that the details remain "hazy."
At a side event earlier Tuesday, Ban said the devastation caused by Hurricane Sandy in the Caribbean and the U.S. east coast should be a wake-up call, showing "that before it's too late, we have to take action."
Climate scientists say it's difficult to link a single weather event to global warming but some say the damage caused by Sandy was worse because of rising sea levels.
A small minority of scientists still question whether the warming seen in recent decades is due to human activities, such as the carbon emissions from the burning of fossil fuels.
"Let us avoid all the skepticism. Let us prove wrong all these doubts on climate change," Ban said.
Climate scientists have already observed changes including melting Arctic ice and permafrost, rising sea levels and acidification of the ocean, shifting rainfall patterns with impacts on floods and droughts.
Low-lying Pacific island states, in particular, are losing shoreline to rising seas, expanding from heat and the runoff of melting land ice.
Governments represented at the Doha conference have started talks on crafting a new global climate treaty that would take effect in 2020. They are also discussing how to rein in greenhouse gas emissions before then, partly by extending the Kyoto Protocol, a treaty limiting the emissions of most industrialized countries that expires this year.
The U.S. never joined Kyoto, because it didn't cover emerging economies such as India and China, which now has the world's highest carbon emissions.
With only a few days remaining to agree on the Kyoto extension and other issues, the head of the U.N. climate change secretariat, Christiana Figueres, reminded the delegates that the "eyes of the world" are upon them.
"Present and future generations are counting on you," she said.