Climate change: Scientists say there is hope

BANGKOK, Thailand — A U.N. panel that has laid out doomsday global-warming scenarios offered some good news Friday: Climate change can be limited, and scientists think it can be done at a reasonable price.

Just as important, the report says, existing technology will do most of the job, if policymakers act quickly. And average citizens can make valuable contributions by adopting small lifestyle changes.

Skeptics, including the Bush administration, said the most stringent recommended measures could strain the world economy. Others doubted the worst-polluting nations would cooperate.

"It's not realistic from a political standpoint, and it's not realistic because those targets are incredibly expensive," said Robert Mendelsohn, a Yale University economist.

Even supporters of the plan were daunted by the speed and scale of action required by the report to stabilize carbon emissions at roughly current levels.

Still, scientists and government delegates involved in the report said they hoped it would serve as a basis for climate discussions at a Group of Eight summit in June and at a U.N. climate summit in December.

The latest report by the Intergovernmental Panel on Climate Change, released Friday, "addresses a fundamental concern of Americans: Can we do something about this?" said Peter Altman, a climate expert at the National Environmental Trust, a nonpartisan nonprofit established to inform citizens about environmental problems and how they affect health and quality of life. "The answer is a resounding yes."

By rapidly ramping up use of renewable-energy sources such as solar, wind and hydroelectric power, making cars, homes and factories more energy efficient, producing electricity with natural gas rather than coal and sequestering carbon dioxide below ground, worldwide temperature increases could be limited to about 3.6 degrees Fahrenheit, low enough to avoid potentially disastrous droughts, severe storms and sea-level rise, the report's summary said. By comparison, global temperatures have risen about 1.5 degrees since the beginning of the Industrial Revolution in the 18th century.

Just as important, substantially cutting greenhouse-gas emissions to levels scientists think would stem increases in warming would cost nations at most 0.12 percent of economic growth each year through 2030, scientists said.

"The bottom line is, all it takes to beat this problem is the political will to put the solutions in hand to work and to invest in clean-energy solutions for the future," Altman said. "To do this at about a tenth of a percent of GDP per year is a very low-cost investment for something with tremendous payoff."

GDP, or gross domestic product, measures the value of all goods and services produced within a nation and is considered the best barometer of the country's economic fitness.

Bush administration officials, who along with representatives of 120 other countries and 2,000 scientists approved the report's policy summary, praised it for highlighting "the importance of deploying a portfolio of clean-energy technologies."

But they said trying to cut greenhouse-gas emissions by 50 to 85 percent by 2050, in line with the report's most ambitious scenarios, would have economic consequences.

The report's primary instrument for reducing such concentrations is a system in which governments would cap emissions and charge polluters for every ton of carbon dioxide beyond that point. That would force companies to cut emissions and invest in energy efficiency and alternative fuels.

The price per ton would reach as high as $100 by 2030. By then, the system could cost up to 3 percent of the world's gross domestic product, the report said.

James Connaughton, chairman of the White House Council on Environmental Quality, said the highest-cost scenario "would, of course, cause global recession, so that is something that we probably want to avoid."

Those costs, however, could drop significantly if the world reaps other benefits from reduced emissions, including more healthful air, greater energy security as reliance on foreign oil drops and export opportunities as newly developed technology is sold and adopted elsewhere, the report's authors said.

The report, the third in a series of U.N. climate-change studies this year, is the first aimed at analyzing solutions.

It suggests major drops in emissions are possible through switching to natural gas rather than coal as a source of electricity, using hybrid and fuel-efficient vehicles, incorporating active and passive solar design into buildings, using more insulation and energy-efficient appliances in homes, improving industrial energy efficiency and encouraging the use of renewable energy sources.

Capturing and storing carbon-dioxide emissions also could lower atmospheric concentrations of the gas, the authors said.

Nuclear power, a controversial alternative to fossil fuels, probably will not gain wide acceptance, if only because of its high cost compared with other options, the report said.

The document also examines a range of policies shown to be effective in promoting emissions reductions, from fuel, road and auto taxes to energy-efficiency standards for appliances, subsidies for renewable energy, mandatory fuel-efficiency standards, investment in public transportation and tax credits.

Voluntary agreements by industries to cut emissions, a favored measure in the United States, for the most part "have not achieved significant emissions reductions beyond business as usual," the report notes, although a few recent efforts have been exceptions.

Probably the easiest and cheapest way to cut greenhouse-gas emissions, the report's authors said, is to focus on improving energy efficiency.

But other key strategies will be ensuring that massive expected growth in developing nations, is cleaner and more sustainable, and that people everywhere cut consumption and emissions without waiting for politicians to act.

That could mean everything from putting on a sweater rather than turning up the heat to buying a hybrid car, choosing a house on a public-transportation line or hanging laundry out to dry rather than throwing it in a dryer.

"It does require lifestyle changes but not any sacrifices," said Jayant Sathaya, a senior energy-technology scientist at the University of California, Berkeley, and one of the report's authors.

The report warns that failure to take quick action to cut greenhouse-gas emissions could lead to concentrations of in the atmosphere more than doubling from the current 425 parts per million by 2100, increasing worldwide average temperatures up to 11 degrees.

A recent European study suggests that if countries fail to stem climate change quickly, they eventually could spend between 5 and 20 percent of their income each year trying to combat its effects.

Material from The Washington Post and Los Angeles Times is included in this report.