On Thursday night, environmental lawyer Robert F. Kennedy, Jr., will step onto a stage in the heart of Appalachian coal country to debate Mr. Coal himself, Massey Energy CEO and global warming skeptic Don Blankenship.

There’s little question who has the home field advantage at the University of Charleston in West Virginia.

Warmer temperatures and rising sea levels are already forcing migrations of animals and plants, and invasive species may be some of biggest winners as habitat are disrupted by climatic changes.

Whether species survive new conditions brought by a changing climate will depend on their ability to move with those changes, says a study in the current issue of the journal Nature. Plants and animals, on average, will have to be able to migrate at a rate of about a quarter mile (0.42 km) a year in order to stay within the ecological "envelope" to which they are adapted, it says.

But as some species' envelopes shrink, others' are expanding, particularly those of invasive species and often at significant economic and ecological cost.

United Nations climate talks in Copenhagen ended without a clear directive to save the world's forests, an issue seen as critical for averting dangerous climate change.

An agreement on REDD, or Reducing Emissions from Deforestation and Forest Degradation in developing countries, was expected to be completed last week as the talks wrapped up.

But the final "Copenhagen Accord" only recognized the importance of ending deforestation; it gave no specifics on what REDD will look like or what it will include.

Reporting from Copenhagen

A much-touted UN forestry scheme aimed at ending deforestation and radically slowing global warming is close to getting approval at the 193-nation UN climate talks, but without any long-term financial commitments to pay for it.

Without money guaranteed from wealthy states, poor nations won't accept targets to end forest loss, making the plan hot air, forest advocates are warning.

Reporting from Copenhagen

UN climate talks on ending deforestation hit a new low on Saturday after a leaked document revealed that immediate targets to halt forest loss had been cut out of a draft agreement.

Poorer forested countries had been willing to accept deforestation targets, but only with financial assistance. They wanted rich countries to commit to providing billions of dollars for the effort before they agreed to bind themselves to any goals.

Currently, there are no dollar commitments on the table.