Today is “Young and Future Generations Day” here at the International Climate Negotiations in Copenhagen, and I’m here with my wife Wahleah and our two-year-old daughter Tohaana. Along with over a thousand other young people, mostly wearing orange t-shirts today, we’re doing everything in our power to convince world leaders to commit to a fair, ambitious, and legally binding international agreement based on a target of 350 parts per million (ppm), which is the safe upper limit of carbon dioxide in the atmosphere.

Less than 400 miles away in Oslo, Norway, President Obama is accepting the Nobel Peace Prize “for his extraordinary efforts to strengthen international diplomacy and cooperation between peoples.” If ever there was a time and place to live up to that honor, now, in Copenhagen is it.

Four former Nobel Peace Prize winners have endorsed a target of 350ppm. On December 12th, 2008, at the international climate talks in Poznan, Poland, Al Gore (2007 winner) said to a huge crowd: “Even a goal of 450 parts per million, which seems so difficult today, is inadequate. We need to toughen that goal to 350 parts per million.”

On December 20th, His Holiness The 14th Dalai Lama (1989) wrote: “It is now urgent that we take corrective action to ensure a safe climate future for coming generations of human beings and other species. That can be established in perpetuity if we can reduce atmospheric carbon dioxide to 350ppm. Buddhists, concerned people of the world and all people of good heart should be aware of this and act upon it.”

On August 25, 2009, Rajendra Pachauri, who accepted the 2007 Nobel Peace Prize on behalf of the IPCC said, “As chairman of the Intergovernmental Panel on Climate Change, I cannot take a position because we do not make recommendations. But as a human being I am fully supportive of [350ppm]. What is happening, and what is likely to happen, convinces me that the world must be really ambitious and very determined at moving toward a 350 target.”

And on October 23, 2009, two days before what CNN called the “most widespread day of political action in the planet’s history”, Archibishop Desmond Tutu, who has been an ambassador for the 350 campaign and won the Peace Prize in 1984, wrote in USA Today: “Many top scientists agree that there’s a number the world needs to know. It’s 350 — as in 350 parts per million of the heat-trapping gas carbon dioxide in the atmosphere. The growing consensus is that it’s the most carbon we can have in the atmosphere without causing terrible climate havoc. Since we’re already past that level, at 390 parts per million, it also implies that we need much swifter political action than governments have supported in the past to reverse this trend.”

It is time for President Obama to join them. It may not be the politically pragmatic path, but it is the only path with the potential to lead to peace and prosperity. The climate crisis is a unique challenge in human history and Copenhagen is a unique opportunity to rise to that challenge. As Bill McKibben writes, “the adversary here is not Republicans, or socialists, or deficits, or taxes, or misogyny, or racism, or any of the problems we normally face — adversaries that can change over time, or be worn down, or disproved, or cast off. The adversary here is physics.”

The physics says the limit is 350 ppm. That is the upper limit for carbon dioxide in the atmosphere if we want Earth to continue to resemble the planet we’ve come to know and love. Despite the fact that we are 390 ppm and climbing and his inaugural promise to “restore science to its rightful place” Obama and the US delegation are negotiating in Copenhagen with a stated target of 450ppm.

Fortunately for us, there are some world leaders who do not view the climate crisis as a primarily political problem. Ninety-two nations, all poor and vulnerable to the early affects of climate change have endorsed a target of 350ppm. President Nasheed of the Maldives has stated “we will not sign a global suicide pact, in Copenhagen or anywhere.” And Ambassador Lumumba, coordinator of the G77 and China Group in Copenhagen made it clear that the $10 billion of “aid” proposed for African countries by Europe and President Obama is ‘not enough for Africa to buy the coffins to bury us in’ if the climate crisis is allowed to continue.

This weekend, people are organizing candlelight vigils around the world calling on world leaders to break through the political logjam. Many will be outside American consulates and embassies, and at Senator’s offices throughout the United States, because without U.S. leadership here, the negotiations will likely fail.

On the Young and Future Generations Day, I look at Tohanna and wonder how she’ll feel in 20 years. Will she look at me and my generation and ask why we didn’t do more? What will I tell her?

If we don’t get this right, right now, what will you, President Obama, say to Sasha and Malia in 20 years? That it wasn’t politically feasible? That we didn’t know the extent of the challenge we were facing?

We know the science. We know the consequences. The United States and you, President Obama, need to continue “to strengthen international diplomacy and cooperation between peoples” and commit to a fair, ambitious, and legally binding agreement based on a target of 350ppm.