In Copenhagen, Denmark, the United Nations Climate Change Conference opened this week. Around fifteen thousand delegates and observers from nearly two hundred countries are there. Some call it "the last best chance" for an agreement to fight climate change.

Yvo de Boer is the top climate official at the United Nations.

UN climate chief Yvo de Boer

But there are questions about how much can be done, and how an agreement would be put into action.

The twelve-day conference ends next Friday. Late next week, leaders from more than one hundred countries are expected at the talks, including President Obama.

Delegates hope to set new targets to reduce greenhouse gases -- the pollution blamed for trapping extra heat in the atmosphere. An existing agreement, the Kyoto Protocol, ends in two thousand twelve. Many countries have offered new proposals for cuts, including the United States and China.

Summit delegates look at a display showing the warming of the world's oceans

In Washington, the Environmental Protection Agency on Monday declared carbon dioxide and other greenhouse gases a threat to public health. That clears the way for the administration to set limits, unless Congress acts first.  

But developing countries are also being urged to do more. And they, in turn, want help. They criticized a proposal for industrialized nations to pay developing countries ten billion dollars a year over three years. The World Bank says dealing with climate change will require hundreds of billions a year in public and private financing.

In New York, the United Nations secretary-general reacted to a dispute over e-mails stolen from the University of East Anglia in England. Critics say the messages show climate change scientists discussing ways to discredit other theories about global warming. But Ban Ki-Moon said Tuesday that the evidence is "quite clear" that humans are the main cause of temperatures rising faster than expected.

Modern climate records date back to eighteen fifty. The United Nations weather agency says two thousand to two thousand nine was the warmest decade on record. And it said this week that final results will likely show two thousand nine was the fifth-warmest year on record.

Current estimates show record warmth this year in large parts of southern Asia and central Africa. The agency reported that the only parts of the world with cooler than average conditions this year were the United States and Canada.

And that's IN THE NEWS in VOA Special English, written by Brianna Blake. For the latest news from Copenhagen, go to 51voa.com.  I'm Steve Ember.