But we are imposing extraordinary stresses on the global environment. Every year, we use more land, contaminate more water, consume more energy, emit more pollutants into the atmosphere and crowd more creatures into extinction. We are engaged in an ongoing experiment in which nature itself is being tested. And the safe limits are something about which we can only hazard an informed guess.

Meanwhile, the world’s population has passed 6 billion human beings – many of whom live in dire poverty. More than 2 billion lack access to clean water; more than a billion subsist on less than $1 per day. And killer diseases such as HIV/AIDS and malaria plague entire continents.

Great strides
What are we doing to change course? The United States recognizes that we must do our part to protect the planet. We have made great strides in cleaning our air, land and water. Thirty years ago, the skylines of many United States cities were disappearing behind a veil of smog, and some of our rivers were so polluted they could literally burst into flames. In little more than a generation, we have reversed decades of damage. Tens of millions more Americans now have clean air and drinking water. Twice as many of our rivers and lakes are now safe for fishing and swimming. We have cut toxic emissions from factories by nearly half – and lead levels in our children’s blood by 70 per cent.

We are also succeeding in reducing the rate of growth of our greenhouse gas emissions. In both of the last two years, our economy grew by more than 4 per cent while our carbon dioxide emissions grew by 1 per cent or less. So we know from experience that economic growth need not bring environmental degradation.

Our citizens cannot thrive if the very air we breathe, the water we drink, the food we eat and the resources we rely on are at risk

But it is clear that addressing such issues will require more than nations acting alone; it will require unprecedented levels of international cooperation. Polluted air and water flow easily across national boundaries, and will thus defeat the efforts of any nation that tries to isolate itself. Many other natural resource issues have the same transnational character. For instance, the range of many fish stocks is so wide that no single nation, acting alone, can properly conserve and manage them. And, of course, climate change and ozone depletion are concerns of truly global proportions, requiring cooperation on a global scale.

Each nation must take steps on its own to combat environmental threats, but we will not succeed unless we learn to coordinate our efforts. And as leaders, our challenge is to forge an international diplomatic response that reflects strong consensus goals which lead to positive and measurable results.

Meaningful participation
This is particularly true in the case of global warming. The scientific consensus is clear that the Earth’s atmosphere is getting warmer. If we do not address the problem, the economic and ecological consequences will be enormous – drought in some areas, floods in others, rising sea levels, spreading disease. The United States has the world’s largest economy and we are the single largest emitter of the gases that cause global climate change. So we have both the capacity and the obligation to lead. But we cannot solve this problem alone. Soon, 50 per cent of global emissions will come from developing countries. That is why we are seeking their meaningful participation.

We can keep wasting water, pumping out carbon dioxide and destroying species. Or we can act now to protect the planet

We also want to ensure that all the world’s people have access to clean water. We have seen the tensions that competition for water can generate, and the suffering that mismanagement and shortages can cause. Studies show that the squeeze on water resources will tighten as populations grow, demand increases, pollution continues and global climate change accelerates. As competition for water intensifies, further disagreements over access and use are likely to erupt. And unless properly managed, water scarcity can be a major source of strife, as well as a roadblock to economic and social progress.

Finally, we must remember that biological diversity is an irreplaceable shared resource and responsibility. For we are losing species at a rate unknown since the extinction of the dinosaurs. Scientists believe that in just the last few decades, human beings have triggered one of the greatest waves of extinction in planet Earth’s 4-4.5 billion year history.

The leading threat to biodiversity is the destruction of tropical forests, which support half the world’s known species. These forests help maintain a stable climate and are a vital source of medicines and new materials. Only half the tropical forests that stood in 1800 survive today. Another 20 hectares disappear every minute.

Joining together
Our choice is clear. We can keep wasting water, pumping more carbon dioxide into the atmosphere, and causing species to disappear faster than scientists can catalogue them. Or we can act now to protect the planet.