Sir David King at AAAS: World Must Strike Emissions-Reduction Pact by 2009

Avoiding "catastrophic" climate impacts that become increasingly possible as atmospheric greenhouse gas levels approach 550 parts per million will require wealthy and developing nations to reach an emissions-reduction agreement by 2009, to allow it to come into force by 2012, the U.K.'s Chief Scientific Advisor said.

"We must get global agreement, and I'm standing here in Washington [D.C.] saying, 'We need it in a very short period of time,'" Sir David King said 13 July during the latest in a series of AAAS appearances since 2004. It is a big ask, King said, but U.K. experience demonstrates that environmental and economic goals need not conflict.

The U.S. Congress is expected in September to begin debating far-reaching measures to reduce emissions of carbon dioxide (CO2) and other greenhouse gasses, including proposals for "cap-and-trade" systems in which industries and utilities can buy and trade emission permits. Europe has pioneered such systems. But as the Washington Post reported 15 July, "because of the complexity of the likely proposals, few expect any bill to become law." Lawmakers have yet to approve even relatively straightforward measures to increase automobile fuel standards or building energy-use efficiency.

Without innovative efforts to mitigate rising carbon dioxide emissions, King cautioned, atmospheric levels "will continue remorselessly upwards." He issued a stark warning of the serious impacts for all countries if levels of atmospheric greenhouse gas (gsg) levels approach 550 parts per million (ppm), with "very dangerous climate effects" predicted even at 450 ppm. But, he also struck an optimistic note, pointing to the Montréal Protocol and the recent "G8 plus 5" summit of eight industrialized nations together with Brazil, China, India, Mexico, and South Africa as signs of progress toward a global commitment to combat climate change.

Further, King explained that gross domestic product (GDP), a conventional measure of national wealth, can be "de-coupled" from CO2 emissions, citing UK experience in this. Action on climate change is entirely consistent with continued prosperity, he said. He added that there is a huge and growing global market for environmental goods and services, predicted to grow from $584 billion in 2004 to $800 billion by 2015. Already, he noted, as part of the European Union's Emissions Trading Scheme, London has since 2005 become a leader in carbon trading, with a market worth more than 9 billion pounds.

With atmospheric CO2 levels expected to reach 400 ppm within the next 10 years and global climate change already underway, King summarized his message this way: "We need a two-track strategy. We must reduce emissions radically to stabilise ghgs in our atmosphere. But we also cannot avoid climate changes that are already in the system from historic emissions. We must therefore at the same time adapt to these impacts we cannot avoid, and we have to do so country by country." Mitigation efforts, meanwhile, should include switching to low-carbon energy sources, increasing energy efficiency, and developing new technologies, he added.

Preparing for change, and providing government planners with the scientific evidence they need to make sound decisions, is the focus of the U.K.'s Foresight program, described in King's 22 June article in Science (vol. 316, pp. 1701-1702). Established in 2001, when foot-and-mouth disease had just begun to strike U.K. livestock, the Foresight program, under King's direction, was instrumental in containing the outbreak. Later, the program produced the first regional study of the potential threat to Britain from rising sea levels and changing rainfall patterns.

"As I go through Washington [D.C.], I hear a willingness to listen to lessons we've learned" in the United Kingdom, said King, who also serves as head of the U.K.'s Office of Science and Innovation. Later, he added: "As we move forward to early next year, I'm very much hoping to see a clear leadership position from the United States" on the climate issue.

In a packed AAAS auditorium, King noted that the basic mechanisms of global warming have been understood since 1896. French scientist Joseph Fourier (1768-1830) was the first to explain the role of the Earth's atmosphere in moderating daytime and night-time temperatures by preventing some solar energy from radiating back into space after warming the Earth's surface. British scientist John Tyndall then discovered the importance of CO2 and water vapor to Fourier's description of the greenhouse effect. Later, Svante Arrhenius of Sweden (1859-1927) calculated that burning enough fossil fuel to double atmospheric CO2 levels would cause the Earth's temperature to rise by 5 degrees Centigrade. Today, King said, computer-based models are essentially confirming the predictions of Arrhenius.

"There's a coupling between CO2 levels and temperature which is clearly demonstrated," he said.

He added that "stunning data," published by Science in 2006 (Fedorov et al., vol. 312, p. 1485), mapped the relationship between atmospheric CO2 levels and temperature over the past 60 million years. CO2 levels began rising about 12,000 years ago, he explained, coinciding with the advent of farming and deforestation, which produces greenhouse gases as vegetation decays. More recently, evidence has shown a sharp increase in CO2 emissions beginning with the industrial age. Atmospheric CO2 levels now stand at more than 380 ppm, King said, and 400 ppm levels are expected within another decade.

At 450 ppm atmospheric CO2, he said, temperatures would increase by 2.2 degrees Centigrade (approaching 4 degrees Fahrenheit). But, the warming could range from 1.7 degrees C to 3 degrees C. Staying below 350 ppm "would have been best," he said, but he acknowledged that given political and economic complexities, stabilization below 450 ppm would now be "unlikely." Once levels approach 550 ppm, he said, "we are looking at very dangerous climate impacts," and above that level—"catastrophic events," including unpredictable feedback mechanisms.

In the United States, crop productivity will be affected, and researchers are investigating many other demonstrated and potential impacts such as tropical cyclone intensity. [See the AAAS Board statement regarding global climate change.] European communities risk suffering unusually hot summers, comparable to the 2003 event linked with 32,000 fatalities. Further, he said, computer models show that continued melting of the Greenland ice sheet could trigger an unpredictable acceleration process, and total disintegration—over the course of millennia—would lift sea levels by 6.5 meters, affecting "50s of millions of people."

"I'm very much hoping that at the G8 summit next year," King said, "we can get a workable agreement on the table."

Citing 11 key challenges for the 21st century, from the food supply to terrorism, King said that two issues—human well-being and sustainability—are most pressing. In evaluating progress toward environmentally sustainable practices, King proposed that countries should focus less on GDP, and more on maintaining a "productive base," including manufactured capital—as defined by Sir Partha Dasgupta, a Cambridge economist. "If a country is producing increased GDP, but taking oil from the ground," King pointed out, "overall wealth will come down unless capital is reinvested."

The European Union agreed in 2007 to cut CO2 emissions by 20% by the year 2020. In the United Kingdom, a draft Climate Change Bill, set forth 13 March, requires a reduction in current CO2 emissions by 60% by 2050, and sets a legally binding 26% to 32% reduction target for 2020. By 2010, the U.K. currently plans to reduce emissions by 20% compared with 1990 levels. An independent Committee on Climate Change will become responsible for helping to ensure that the United Kingdom stays on track toward meeting its goals, King explained.

Under the U.K. plan, utilities are required to increase investment in renewable energy sources. Wind farms, equivalent to two gigawatts' worth of energy, are already in place, and another nine gigawatts are planned. The U.K. plan also focuses on increasing energy efficiency—particularly related to buildings—nuclear power, and carbon capture and storage (CCS). King said that, in fact, CCS is "key to it all." He added that solar energy merits additional investigations as well. "We need to look at ancient technologies," he said, "but also modern ones."

King also identified a cap-and-trade system as essential to getting greenhouse emissions under control, both within individual nations and worldwide. In simple terms, a cap-and-trade scheme imposes strict limits on emissions from a group of industries, then grants permits for emissions; a market is created in which the permits can be sold by those who emit less and bought by those who emit more. Over time, the number of permits is reduced.

Europe has pioneered such a system, but the value of the permits at one point collapsed, King said. The problem: When individual countries did not propose strict emission limits, the market concluded that those permits had little value. But when European Commission President José Manuel Barroso signalled that the Commission would use the U.K.'s stricter emission limits, the value of the permits rose again on the cap-and-trade market.

Eight bills currently pending in Congress would create a cap-and-trade system in the U.S. "I wish the proposals well," King said.

The next green revolution will require additional investment in both mitigation and adaptation strategies, including the transfer of additional support from wealthy to developing regions and widespread changes across society, King concluded. Until now, he said, "consumerism has been a wonderful driver," but in the future, "I'm not sure rampant consumerism will deliver what we need." We need to re-think our throw away society, he added.

AAAS CEO Alan I. Leshner, executive publisher of Science, noted during his introductory remarks that King eloquently addressed the AAAS Annual Meeting in Seattle, Wash., in 2004, then spoke again at AAAS headquarters in 2005. "I've been struck by his efforts to protect the integrity of science," Leshner said as he welcomed King back to AAAS.

Ginger Pinholster

18 July 2007