I haven't been here very long; indeed, I've been here shorter than you [Dean Stephen W. Bosworth] have. But based on what I have seen here, you're off to a flying start. Congratulations. You are trained to lead, to serve and to administer, and you've done a great job with this weather.

Let me start by saying, it gives me great pleasure to join you for this very special day.

You are no doubt aware that Fletcher alumni have served with distinction in the United Nations and  the diplomatic services of the Organization's Member States. So there is a very special connection between this institution and the one I am proud to serve.

It is also good to be back in the Greater Boston area. I hope I won't offend you by saying that I have very fond memories of my own time as a graduate student at a nearby rival of yours, the Sloan School at MIT.  You guys are really generous...you applaud even for the competition.

I paid my dues by giving a commencement address there, four years ago.  Some of you may think you have read that one, since I gather a spoof version has been circulating on the Internet - attributed sometimes to me and sometimes to the author, Kurt Vonnegut.  I am flattered by the association, but in fact neither of us was responsible for the famous advice to graduates to "sing", "wear sunscreen", and "done thing a day that scares you". In my case, such advice is quite redundant.  I have no need to wear sunscreen, as you would hardly catch me tanning in the sun and singing by itself would be enough to scare me for more than a day!! And probably you too, given the way I sing. 

So I know how hard it will be for you to leave a campus and a city that has sheltered  and nurtured your growth. But leave you must. First, because you probably have enormous school loans to pay off! And above all, because there is urgent work to do.

I want to talk to you today about climate change, which I believe may well be the greatest challenge that your generation will have to face.

For more than a decade now, the international community has been building -- law by law, institution by institution, technology by technology -- an innovative and far-reaching response. In 1992, an agreement was adopted aimed at stabilizing atmospheric concentrations of greenhouse gases at safe levels. The United States was the first developed country to ratify it.

Five years later, the parties to that treaty negotiated the Kyoto Protocol, which would commit developed countries to significantly reduce their greenhouse emissions. But the Protocol has yet to enter into force, because of serious disagreements over how to achieve the desired reductions.

There are differences over how much we should rely on emissions trading, which would allow countries that reduce emissions by more than their allotted amount to sell their "right to emit".

There are differences over how countries should be credited with reductions by increasing their forest cover, which absorb carbon.

And there are differences over how industrialized countries would get credit for climate-friendly investments in the developing countries.

The United States, as you probably know, is the world's leading emitter of greenhouse gases, largely because it is the world's largest and most successful economy. That makes it especially important for it to join in reducing emissions and in the broader quest for energy efficiency and conservation. Indeed, there is concern throughout the world about the decision of the new Administration to oppose the Kyoto Protocol.

Today we face the very real danger that the hard-won global gains in combatting climate change will experience a grievous setback. Developing countries would be left most vulnerable, even though they are the least responsible for global warming. But make no mistake: all countries will suffer. Climate change cares little for the borders drawn by men.

Imagine melting polar icecaps and rising sea levels, threatening beloved and highly developed coastal areas such as Cape Cod with erosion and storm surges. Imagine extreme weather causing billion-dollar calamities. Imagine a warmer and wetter world in which infectious diseases such as malaria and yellow fever spread more easily.

This is not some distant, worst-case scenario. It is tomorrow's forecast. Nor is this science fiction. It is sober prediction, based on the best available science. The Intergovernmental Panel on Climate Change, a group of the world's leading climatologists and others -- including many from the United States -- has carefully sifted the evidence and concluded that climate change is occurring, that human activities are among the main contributing factors, and that we cannot wait any longer to take action.

Negotiations on climate change resume in July. I can think of no better moment for everyone to reflect on this global threat, and to consider what more we can do in response. Far more is within our powers than is commonly understood.

Contrary to popular belief, we do not face a choice between economy and ecology. It is often said that protecting the environment would constrain or even undermine economic growth. In fact, the opposite is true: unless we protect resources and the Earth's natural capital, we shall not be able to sustain economic growth.

We should also remember that environmental costs -- for example, the costs of cleaning up polluted areas or repairing damage -- are rarely reflected in national accounts. Nor are harmful side effects, such as the health costs of air pollution from smokestack industries or from gas-guzzling vehicles. Moreover, the costs of inaction are often ignored. We must stop being so economically defensive, and start being more politically courageous.

Technological progress should help put to rest another myth, which holds that solutions to global warming must wait for discoveries to be made by future generations. In fact, hundreds of these technologies and practices exist today. And in recent years, advances in the use of renewable resources have been exceeding expectations.

It is also said that conservation, while admirable, has only limited potential. But economists now broadly agree that improved energy efficiency and other "no regrets" strategies could bring great benefits at little or no cost.

Enlightened corporate leaders are already seizing the opportunity to use and develop green technology. Many Governments are pushing this transition along through creative use of tax and fiscal policies, notably by eliminating the enormous subsidies that have sustained many harmful practices. And many major energy suppliers agree that technical, financial and economic obstacles to a less damaging energy future are all rapidly disappearing.

Next year in Johannesburg, a World Summit on Sustainable Development will assess the progress made since the Earth Summit almost a decade ago. Since then, public awareness has grown, several important treaties have been adopted and citizens' groups have kept a spotlight on the issues. But in key respects, we have gone on with business as usual.

All world leaders must show they take these issues seriously. But it is the leaders of the industrialized world who must show the way, especially on the question of global warming. Developed countries are responsible for most of the world's current greenhouse gas emissions. And they are best placed, both economically and technologically, to make -- and help others make -- the necessary changes.

Developing countries will have to do their part in due course; their exclusion from emissions commitments, it should be stressed, is only for the first phase. Already, China and other developing countries are limiting the growth of their emissions through market reforms and by closing down inefficient coal-burning operations.

Over time, the legal framework provided by the Convention and Protocol will have to evolve. The battle against global warming is one that will have to be waged for generations. And let us not see this as only a burden, for it is also an exceptional economic and social opportunity. With the right mix of policies and practices, we could generate a positive ripple effect across many realms of human need. We could reinvigorate the fight against poverty, especially by providing sustainable energy services to the two billion people who lack access to electricity.

We can inspire changes in corporate and consumer habits. and here, individuals like you can make a difference through the choices and purchases you make help send a strong message to corporations and governments.  Ultimately, I believe, we can shape globalization so that the environment does not become one of its prime casualties.

The enterprise of international cooperation itself could benefit -- or suffer. What happens in the fight against global warming will tell us what kind of international community we are building: one that can anticipate threats, and then contain or avert them; or one that is content to reel from crisis to crisis, that feels little sense of global solidarity or responsibility.

Admittedly, the international community as we know it today is only in embryonic form. But it has a vision, as enshrined in the United Nations Charter. It has a language: the language of international law. Your Fletcher degrees give you the tools with which to help the international community pass not only the climate change test, but the many others we must face together.

My Dear Friends,

Time was once on our side in undertaking major environmental policy initiatives. Today, though we have the human and material resources to win the fight against climate change, the time for a well-planned transition for sustainable development is running out -- unless, that is, you do your part.

As you collect your well-earned degrees, allow me to wish you a life in which you can take full pleasure in the natural environment, while recognizing the urgent need to preserve it. I wish you every success, from business to family life, while encouraging you to be aware of the public implications of your private pursuits. Most of all, I wish you long and rewarding lives in your communities, while hoping that the international community will also benefit from your talents and ideas.

Thank you very much. And congratulations, once again, on this very special day.