By Lisa Speer

As I type, NRDC Global Leadership Council member Larry Lunt and Belgian explorer Alain Hubert, co-founder of the International Polar Foundation, are trekking across Greenland's Humboldt Glacier, getting a firsthand glimpse of the area of the world showing the most obvious and advanced signs of global warming.

The Arctic ice cap is melting. Summer Arctic sea ice fell in 2007 to the lowest level since satellite measurements began in 1979, and scientists now predict that the Arctic may become ice-free in summer as early as 2013. This will have dramatic impacts on the entire ice-based marine food web, from plankton to polar bears, and on the Arctic peoples who rely on these animals. Larry and Alain will likely see signs of these and other profound changes on their travels.

On top of melting sea ice and warming ocean temperatures, additional impacts are likely from new or expanded industrial activity - fishing, shipping, oil and gas development, cruise ship tourism - made possible by the retreat of the ice.

The first order of business is to get our climate house in order, and agree on dramatic reductions in CO2 emissions. NRDC is fully engaged in working with the international community to reach an agreement at the December United Nations climate meeting in Copenhagen. There is a unique opportunity for the U.S. to help lead the world to a strong global agreement. We have our work cut out for us this year, but NRDC is committed to working with the new administration and Congress to move as quickly as we can domestically to help progress internationally.

But even if such an agreement were reached tomorrow, warming already in the system will continue to propel many of the changes in the arctic already under way, including new industrial development.

Managing human activity in the region itself in a way that maximizes the resilience of Arctic ecosystems in the face of all these changes is the Arctic trek that I'm on. I will blog periodically about this topic, and hope you will join in the conversation.

Is global warming a crisis? See the Opposing Views debate.