At the climate conference in Copenhagen, there’s been considerable discussion over how to put a price on reducing carbon emissions. Generally, placing a price on a commodity — corn or soy or a car — is a fairly easy matter in an established marketplace. But carbon is not a commodity, and there’s no established marketplace for carbon, so the effort presents particular challenges.

Negotiators at the Copenhagen climate summit are facing an uphill task in their attempt to come up with a political agreement on global warming. Listeners ask how a developing nation is defined, about efforts by some countries to become carbon-free, the difference between global warming and climate change, and what to expect from the summit.

As world leaders streamed into Copenhagen, disputes have left big issues unresolved just two days before participants hope to sign a historic accord to fight global warming. Meanwhile, hundreds of protesters tried to disrupt the conference, and police said 230 were detained.

Bjorn Lomborg, author of The Skeptical Environmentalist, is roaming the halls of the U.N. climate talks in Copenhagen. While Lomborg believes climate change is real, he thinks the approach being taken to fight it is doomed to failure. Lomborg also famously led a team of economists who ranked climate change low on a list of priorities when compared to things like combating disease. Needless to say, Lomborg is not a popular figure at the talks.

Climate scientists say Colombia’s glaciers could disappear within 15 years. Wet highland areas that provide much of the country’s fresh water are getting warmer and drier. And each year, flooding becomes more severe. The coastal area of Tumaco has become an example of how environmental and security pressures are undermining previously stable communities.

The U.N. climate talks in Copenhagen made little visible progress this past week on a treaty to combat global warming. Host Liane Hansen speaks with NPR’s David Kestenbaum, who is in Copenhagen covering the conference.

New research shows that if carbon emissions soar, we could end up with super-sized lobsters. But you’ll have to strap that bib on fast. Those same environmental conditions could spell trouble for the critters that lobsters eat — and ultimately for the jumbo crustaceans themselves.

President Obama delivered his much-anticipated speech in Oslo Thursday as he accepted the Nobel Peace prize. Also this week, Britain and France announced a massive tax on bonuses. E.J. Dionne of The Washington Post and David Brooks of The New York Times offer their insight.

India is the planet’s fifth biggest carbon polluter. Even with its vast population, its per capita emissions are many times lower than the West. As India’s economy grows, so will its pollution. India’s government has announced measures to combat climate change. But some question whether it can carry them out. The city of Gurgaon has become the front-line in a battle between government and growth.

French President Nicolas Sarkozy wants his country to take the lead in the fight against global warming. He is pushing through a radical and unpopular plan to tax individual households according to their carbon footprint. But the new measure has many seeing red, not green.