AAAS President John P. Holdren (pictured right) used his presidential address to urge swift action to build a sustainable future. Challenges such as poverty, climate change and nuclear proliferation pose global risks that require scientists and engineers to join with political and business leaders in a concerted search for solutions, Holdren said in opening the association’s annual meeting.

Here in San Francisco, Holdren, who is director of The Woods Hole Research Center in Massachusetts and the Teresa and John Heinz Professor of Environmental Policy at Harvard University, described a world poised at an unprecedented moment of decision. Without swift and urgent action, he said, the problems could spiral toward disastrous, permanent changes for all of life on Earth.

Holdren’s address, entitled ‘Science and Technology for Sustainable Well-Being’, was a sweeping review of evidence which, taken together, shows a planet under profound stress. He said that one of the central problems, and the most complex, is ending the reliance on fossil fuels that is damaging and destabilising the Earth’s ecosystem. “Reliable and affordable energy is essential for meeting basic human needs and fuelling economic growth,” he said. “But many of the most difficult and dangerous environmental problems at every level of economic development arise from the harvesting, transport, processing, and conversion of energy.”

To address the gathering challenges, he said that world leaders would have to work on a range of fronts – economic, diplomatic and technological. He urged scientists and engineers to get personally involved in developing solutions, and he drew a standing ovation when he called on them to “tithe” 10% of their time to “to working to increase the benefits of science and technology for the human condition and to decrease the liabilities.”

In his address, Holdren identified four key S&T challenges for achieving sustainable well-being: Meeting the basic needs of the poor; managing the competition for land, soil, water, and the net primary productivity of the planet; mastering the energy-economy-environment dilemma; and moving toward a nuclear-weapon-free world.

But he offered compelling evidence that the world is not making sufficient progress on any of those challenges. For example, he said, efforts to meet the UN Millennium Development Goals have been uneven, at best. Child mortality levels show improvement, but remain “really appalling.” And he described the United States as the “second stingiest” among nations in the Organisation for Economic Co-operation and Development in providing assistance as a percentage of gross domestic product. [Only Italy ranks lower, he said.]

On environmental and climate issues, Holdren stressed that the emergency is not looming in the future, but is having a palpable impact now. “Climate change is not a problem for our children and our grandchildren – it is a problem for us,” he said. “It’s already causing harm.” 2005 was the hottest year on record, he said. The 13 hottest years on record all have occurred since 1990. 23 out of the 24 hottest years have occurred since 1980. The sort of heat wave that killed 35,000 people in Europe in the summer of 2003 is expected to become normal by 2050.

By 2100, he said, some projections say global temperatures could rival those of the Eocene epoch some 35 million years ago, a time of dramatic global warming that caused dramatic disruptions – waves of extinction – in Earth’s ecosystem. He quoted a colleague who envisioned “crocodiles off of Greenland and palm trees in Wyoming.” But the warming temperatures don’t simply make the weather warmer, they destabilise the weather and generate more extremes, Holdren observed. Some areas are getting wetter; others are experiencing unusual long-term droughts. Cyclones are becoming more powerful. Between 1950 and 2000, the number of major floods and wildfires has increased dramatically in almost every region of the world.

Holdren suggested that addressing such challenges effectively to improve the overall well-being of humanity will require a radical reconfiguration of policy and economies – and daily life – on a global scale. World leaders would have to cooperate as never before. Such cooperation would have to yield new commitments and strategies to resolve the crushing poverty that affects perhaps two billion people. Further, he noted that a cap on carbon emissions or a carbon tax to encourage use of alternative fuels is “desperately needed”.

Against such a backdrop, the threat of nuclear war or terrorism presents a further risk of global destabilisation and a threat toward sustainable well-being, said Holdren, a long-time advocate of nuclear disarmament. Prohibition of nuclear weapons “is not only a practical but a legal and moral necessity,” he argued. There would be challenges and risks in a world where nuclear weapons had been eliminated, he acknowledged, “but they would be far smaller than the dangers of a world in which nuclear weapons are permitted and thus, inevitably, widespread.”

Holdren said solutions must be pursued across a range of channels – economics, science, medicine, technology, and education. And those strategies must be applied to a range of related problems – providing clean water and medical care, reducing carbon emissions, checking deforestation and improving public understanding of actions that can address the challenges at hand.

To address climate change, there could be “geo-engineering” projects to help cool the atmosphere or to remove greenhouse gases from the atmosphere, he said, though they would likely require enormous investment. But he cautioned against expectations that a single technological solution such as nuclear fusion would emerge to solve energy and climate problems. “Belief in technological miracles,” he told reporters, “is generally a mistake,” a point with which we in STEPS would fully agree.