Lukewarm response from scientists to US-China climate change deal
Landmark US-China pact is a start but other countries need to join in, say scientists
Don't expect the landmark US-China climate change agreement to nudge the world's rising thermostat downward much on its own, scientists say.
While they hail it as a start, experts who study heat-trapping carbon dioxide don't see the deal, announced on Wednesday in Beijing, making significant progress without other countries joining in. The maths shows that even with the agreement, the globe is still rushing toward another 2 degrees Celsius temperature rise - a level that world leaders have pledged to avoid as too dangerous.
China, the world's No1 polluter, will still increase its emissions until 2030 or so, under the agreement. The US, which ranks second, promised to cut pollution from the burning of coal, oil and gas to levels that haven't been seen since 1969. But whatever cuts the US makes will be swamped by the Chinese growth in pollution over the next 15 years.
"It doesn't change things much," said Glen Peters, a Norwegian scientist who was part of the Global Carbon Project, an international team of researchers that tracks and calculates global emissions every year. "This is not far off the business as usual" scenario the world is already on, he said.
In 2009, countries across the globe set a goal of limiting global warming to about 1 degree above current levels. Peters' team has calculated that the world would hit that mark around 2040 and the US-China accord doesn't change that, he said. The numbers are just too big, especially out of China.
Professor John Sterman, of the Massachusetts Institute Technology, who runs computer simulations of global emissions, compared the numbers to a driver with his foot all the way down on the accelerator in the fog heading toward a cliff. While this agreement helps, it's only letting up on the pedal, not slowing the car.
World leaders forged the first international treaty to combat global warming in Kyoto, Japan, in 1997. But developing countries, including China and India, were not required to reduce greenhouse gas emissions and that caused a big rift. The United States signed the agreement, but did not ratify or honour it.
After only non-binding goals were adopted in 2009 in Copenhagen and a UN summit earlier this year, international leaders are now aiming to forge a follow-up agreement in Paris in late 2015.
Climate Interactive, a group that makes projections on emissions, has run simulations that showed the new agreement will mean about 700 billion tonnes of carbon dioxide will be kept out of the air by 2100, reducing expected cumulative carbon pollution by about 8 per cent. That would only prevent temperatures from rising about two-tenths of a degree, said Andrew Jones, co-director of the project at MIT. If all other countries followed the US-China example, temperatures could be reduced by as much as 0.8 degrees.
In the agreement, China set a target for its emissions to peak in 2030 or earlier. That's the first time China has set a deadline for stopping its emissions growth. China also said it would increase the share of clean energy sources like wind and solar power to 20 per cent by 2030, about double what it is today. The US-China agreement, even when combined with pledges already on the table from other nations, represent only half of the world's carbon dioxide emissions. Much of the rest are coming from the developing world, which are likely to see their carbon pollution soar, said Henry Jacoby, also of MIT.