Sir David King: World Faces a “Very Big Challenge” in Soaring Human Population

The 20th century brought remarkable progress in science and human welfare, but the scientific community now faces daunting new challenges driven by anticipated population increases, according to the former top science adviser for the United Kingdom.


Sir David King

Sir David King, the chief scientific adviser to the UK government from 2000 to 2007, told a AAAS audience that with life spans generally increasing and global population projected to reach 9 billion by 2050, population trends will be at the heart of issues such as food production, water scarcity, energy security, and health care.

The prospect of 9 billion people “is a very big challenge,” King said. “Basically today we are using the natural resources of the planet at a rate faster than they’re being replenished.” He said the big question is “whether humanity has the savvy at this point to begin to do a better job in managing” the planet’s resources.

King, now director of the Smith School of Enterprise and the Environment at the University of Oxford, gave a 1 December lecture, sponsored by the AAAS International Office, on “Twenty-First Century Challenges for the Scientific Community.” He is also director of research in physical chemistry at Cambridge University.

King said the most effective way to curb population growth, short of mandating one-child families as in China, is to promote education of women and female empowerment, including access to contraceptives.

Beyond the concern about population, he said, the biggest challenge for the 21st century will remain climate change, a topic being addressed by world leaders in Copenhagen, Denmark.

The atmospheric level of heat-trapping carbon dioxide is now 389 parts per million and is rising about 2 parts per million each year. The best that probably can be achieved, King said, is to stabilize carbon dioxide levels at 450 parts per million, a target that will require reduction of annual global emissions from about 35 billion tons today to 18 billion tons by mid-century. Assuming a population then of 9 billion, that would mean an allowance of no more than two tons of carbon dioxide per person per year. Britain now produces about 10 tons per person per year, King said.

The global economic downturn has bought a little bit of time, he said. There are projections that global greenhouse emissions may be down 15 % or more by 2020 from the “business as usual” curve of a just a few years ago. Still, he said, there remains an urgent need for a global agreement to reduce greenhouse emissions.

Asked about controversial e-mails stolen recently from the climate research group at the University of East Anglia, King said he supports an inquiry to determine whether the e-mails reflect any break down in scientific practices. He acknowledged that skeptics of global warming “have been given a lot of oxygen” because of the hacked e-mails.

But he also stressed that the underlying scientific data on climate change is sound. Much of the debate in the e-mails involved three decades of anomalous tree ring data, he said, that do not show the upturn in global temperatures in the last 30 years as measured by thermometers. “The reliable piece of data is the thermometer data,” King said.

“Of course,” he added, “the scientific community needs to manage the highest standards of rigor in all of its work.”