Imagine that a huge asteroid is hurtling towards Earth. Scientists tell us that there is a 10 percent chance of a collision in 10 years and the consequences of its impact will be catastrophic. Your government advises you not to panic and reminds you that there is a 90 percent chance that the asteroid will miss the Earth. Do you decide not to worry, or do you demand that your government mobilizes all of the resources at its disposal to eliminate the risk? We know that even in this fictitious - although not unthinkable - scenario, a variant of which constitutes the opening of Scott Barrett's excellent book on global issues, the world would act to find a solution without a second thought. Governments would invest in whatever it takes to divert the asteroid from is predicted trajectory. The analogy with climate change is not perfect. Potential catastrophe for the world as a whole is a more long term risk. On the other hand it would be more accurate to compare climate change to a family of asteroids, a big one threatening us all, but further away, and a group of medium sized ones which are likely to hit the poorest countries at lower latitudes much sooner and with much greater certainty than the large one that may hit us all later. As the final report of the UN Intergovernmental Panel on Climate Change concluded, climate change is now a scientifically established fact. Many uncertainties remain, but we know enough to recognise that there are large long-term risks, including the melting of ice-sheets on Greenland and the West Antarctic, massive loss of biodiversity and changes in the course of the Gulf Stream that would seriously alter weather patterns and constitute a risk for the human family as a whole. UNDP's Human Development Report 2007/8, Fighting climate change: Human solidarity in a divided world released in Brasilia this week at an event hosted by President Lula, focuses on the challenge climate change is for development. If average temperatures are allowed to rise by another two or three degrees Centigrade over current levels, we could see an extra 600 million people in sub-Saharan Africa go hungry; over 300 million more poor people flooded out of their homes, and an additional 400 million people exposed to diseases like malaria, meningitis and dengue fever. In other words, failure to act on climate change will have grave consequences for human development in some of the poorest places in the world and it will undermine efforts to tackle poverty. It is the poorest countries that will bear the biggest burden of climate change in the short-term, but they have contributed very little to the stock of heat-trapping gases in the atmosphere. This presents an ethical challenge: the past and ongoing actions of rich countries immediately threaten some of the most vulnerable people in the world. The challenge of climate change will require collective action, with global participation, but justice and political feasibility dictate that rich countries should provide leadership and move first. Consider that if every person in the developing world had the same carbon footprint as the average person in Canada or the US, we would need nine planets to absorb all of the pollution. But we only have one planet. Rich countries have the financial resources and technological capabilities to initiate deep and early emissions cuts. The Human Development Report stresses that putting a price on carbon is the central policy requirement. We urgently need powerful price signals to support a low carbon transition. Huge investments will need to provide the energy that has to continue to support world growth and the jobs for our children worldwide. It is critical that these investments take a form that protects our climate. Even with effective mitigation that starts right now, past emissions make some serious climate change impact already unavoidable on much of Africa, many small island states and the big Asian river deltas. While we work on transforming the nature of our energy and other means of limiting climate change, we must help the most affected populations cope with what is unavoidable without further delay. As the report concludes, future generations will pass harsh judgement on a generation that looked at the evidence on climate change, understood the consequences, and then continued on a path that consigned millions of the world's most vulnerable people to poverty and exposed future generations to the risk of ecological disaster. While we live in a world where people are still separated by vast gaps in wealth and opportunity and national borders, our destinies are inextricably tied to each other by the one thing we all share in common: planet Earth. Kemal Dervis is the United Nations Development Program Administrator.
