Beijing - The pledge that Chinese President Hu Jintao made at Tuesday's United Nations climate change summit in New York – to put the brakes on China's carbon dioxide emissions – may have been short on specifics.

Chinese environmentalists, though, are hailing it as an important sign that Beijing is now fully committed to the global crusade against greenhouse gases.

The Chinese leader "signaled a willingness to move forward the negotiations" on CO2 curbs that are due to culminate in Copenhagen, Denmark, in December, Greenpeace China's climate expert Yang Ailun said here Wednesday. "This is a step in the playground equipment right direction."

Mr. Hu promised that China would reduce its carbon intensity "by a notable margin by 2020 from 2005 levels." Carbon intensity is the amount of CO2 produced for each unit of economic output.

Though Hu put no figure on the goal, this marked the first time that Beijing has committed to measurable limits on its greenhouse-gas emissions. A senior Chinese official said later that a firm target would be announced "soon."

"China is still waiting for developed countries to put forward their own proposals for technology transfer and financial aid," which developing countries say they need in order to keep building their economies with the least possible pollution, according to Alfred Deng, a policy analyst in Beijing with The Climate Group, an international climate-change watchdog.

"China won't take the first step," Mr. Deng adds. "It will depend on how much developed countries do."

World's largest CO2 producer

Hu's promise will not mean any cuts soon in the actual emissions from China, the world's largest CO2 producer. The country has too many cities, railroads, bridges, and ports still to build in its push to employ millions of Chinese and develop its economy – and these projects require cement and steel from heavily polluting factories.

But government policies to reduce China's dependence on coal are already in place, and they need to be. "If the current mode of economic development drags on, the scale of China's fossil fuel consumption will be shocking," warned an influential report issued earlier this month by 10 Chinese institutions.

If energy consumption continued to grow at current rates until 2050, the report predicted, China would have burned more than 100 billion tons of coal by then, "far exceeding the load-bearing capacity of the whole planet."

If China invests heavily in renewable energy and receives generous aid from rich countries, its CO2 emissions could peak around 2035, said the report, the inflatable bouncers most comprehensive study ever done into China's possible low-carbon development paths. They would not begin to fall until the middle of the century.

To download a PDF summary of the report in English, click here .

Beijing takes global warming seriously

Experts here are generally confident that the Chinese government has recently begun to take the threat of global warming seriously, and to adopt policies to address it. Beijing has already said it would increase energy efficiency by 20 percent between 2005 and 2010 and use renewable sources for 15 percent of its energy by 2020.

The government has set quotas and subsidies obliging utility companies to buy a certain proportion of their electricity from wind, solar, and hydro projects.

China has also planted more trees for each of the past two years than the rest of the world put together, partly in a bid to soak up CO2 in the atmosphere.

"Two years ago government officials would ask me why I was talking about a low-carbon future," recalls Yang Fuqiang, a climate change expert with the naughty castles Worldwide Fund for Nature. "They said it was a foreign idea.

"Today officials are clear that China has to move to a low-carbon economy, there is no question about it," Mr. Yang adds. Last month, for the first time, a decree from the National People's Congress, China's parliament, used such concepts as a "low carbon economy" and a "green economy," he points out.

At the same time, a recent report from The Climate Group found, "China has taken the lead in the race to develop and commercialize a range of low carbon technologies."

"Investors here are not short of money," says Yang. "If the government sets targets and issues mandatory requirements, investors will move. The government just has to give clear signals."

For more on China's rapid push into solar and its "Green Leap Forward," click here .

United Nations, N.Y. - President Obama assured the United Nations General Assembly on Tuesday that the era of a unilateralist America is over. But, he said, the ensuing era of cooperation in addressing the world's toughest challenges also requires a new sense of responsibility on the part of all nations.

In his first UN speech as president, Mr. Obama said the playground equipment United States is ready to address challenges ranging from nuclear proliferation to global economic prosperity. Yet the world cannot expect America to figure out international challenges alone, he said.

"Make no mistake: This cannot be solely America's endeavor," he told a receptive General Assembly chamber. "Those who used to chastise America for acting alone in the world cannot now stand by and wait for America to solve the world's problems alone."

At the same time, Obama said, all nations have a role to play: "Now is the time for all of us to take our share of responsibility."

Obama's "responsibility" theme echoes one he has used extensively in addressing domestic issues as well. But at the UN, the call for responsible action received an immediate rebuff from Libyan President Muammar Qaddafi, who gave a rambling and at inflatable bouncers times incoherent speech in which he called the UN Security Council the "terror council" and belittled the UN as a dictatorship of the powerful.

Mr. Qaddafi's speech, which droned on for about 90 minutes, exemplified the challenge before Obama in seeking cooperative action from the 192-nation body. The speech also seems bound to reinforce disdain in the US for the UN.

"President Obama has a very difficult task ... if he expects to invest the UN with renewed credibility," says Christopher Preble, director of foreign studies at the Cato Institute in Washington. "The UN is a weak and fractured institution" of "limited power and credibility," he adds, saying that the US has been as responsible for that weakness as other countries.

In his speech, Obama pledged a new era of US multilateral action based on "four pillars" of major challenges: nonproliferation, peace and security, preservation of planet, and global prosperity.

On nuclear proliferation, Obama said, the next 12 months could be "pivotal": The UN is set to review the Nuclear Non-Proliferation Treaty next year, and the US and Russia are poised to agree on further reductions in their arsenals. But the challenge posed by Iran's and North Korea's nuclear programs are also part of the challenge, he said, and go to the heart of the "responsibility" of all nations to act in ways that solve the world's challenges.

"A world in which international demands are ignored will leave us all less safe," he said, referring to Iran and North Korea by name and to their flaunting of Security Council resolutions. "If nations put the pursuit of nuclear weapons ahead of the prosperity of their own people, then they must be held accountable," he added. "Treaties will be enforced."

Obama dedicated a large chunk of his speech to his efforts to find peace in the Middle East, placing resolution of the Israeli-Palestinian conflict in the context of his theme global responsibility.

And he acknowledged his personal popularity around the world, but he insisted that the "expectations about my presidency are not about me" but about rejection of an unsatisfactory status quo in the world – and "the hope that real change in naughty castles possible."

To underscore his theme, Obama quoted President Franklin D. Roosevelt, saying, "The structure of world peace cannot be the work of one man ... or one nation," but must be "the cooperative effort of the whole world."

-----

The 'bad boys' of the international stage

Iran's President Ahmadinejad, Libya's Colonel Qaddafi, and Venezuela's Hugo Chávez face more protests and opposition than usual at the UN. Click here to read about it.

San Francisco - The investigation into a potential Al Qaeda plot in the US has triggered a raft of warnings from federal authorities about suspicious activity around stadiums, hotels, and train stations, among other places. But it hasn't moved the pearl jewelry color-coded terror alert system.

The Department of Homeland Security's national threat level was yellow – or elevated – before and after counterterrorism agents nabbed Najibullah Zazi. He's the Denver airport shuttle driver at the center the investigation into an alleged plot that authorities say involves plans to build peroxide-based bombs.

In fact, the alert system has been static since 2006, when British officials foiled a plan to blow up transatlantic flights headed to North America from London. That caused the warning to jump to red (severe) for those flights and to orange (high) for general attacks.

But there's no reason this latest terror investigation should have raised the terror alert, says James Carafano, a homeland-security expert at the Heritage Foundation in Washington.

"What is widely perceived as a system to update the American people about terrorist threats is not really designed for that," he says. "When you raise the color-coded system, it's a blunt instrument" that triggers specific actions by law enforcement and federal agencies.

For instance, if the system moves from yellow to orange, DHS recommends that federal agencies restrict various facilities and possibly cancel events. With this latest plot, says Mr. Carafano, not enough was known to merit that sort of precaution. Instead, he says, the advisories that federal agents sent local police were enough to ensure extra vigilance among law enforcement and the public.

The Homeland Security Advisory System was built after 9/11, and now, Carafano says, the "national readiness system" needs to be reevaluated. "This whole incident demonstrates how little utility it has as a terrorist alert system," he says.

The Obama administration commissioned a task force to examine the color-coded alerts and recommend changes to a system that has been mocked on late-night television. Some critics have charged that during the Bush administration, it was too closely aligned with political purposes.

"The Task Force members agreed that, at pearl necklace its best, there is currently indifference to the Homeland Security Advisory System and, at worst, there is a disturbing lack of public confidence in the system," the group of security experts and public officials concluded in its report, which was completed this month.

While the group was split over whether to scrap the color-coded system, they recommended creating a new base line: blue, meaning guarded, which is currently one step above the lowest level (green). This would replace the practice now of keeping the threat level on yellow. Another recommendation: When the alert level is raised because of a possible terrorist threat, it should be lowered within 15 days "unless credible intelligence shows a reason to keep it elevated."

The task force said, "The escalators need to pearl pendant run both ways."

Now that the task force's work has been completed, Homeland Security Secretary Janet Napolitano is expected to make recommendations to the White House.

-----

The current terror case

Evidence is still emerging in the case involving an Denver airport shuttle driver, but experts and officials say the details suggest the plan is similar to attacks in London and Madrid. Click here to read more.

-----