US Environmental Protection Agency (EPA) Administrator Gina McCarthy is going to China to discuss the two countries' cooperation on clean air and climate change, a trip she is excited about and hopeful for fruitful results, she said at a briefing in Washington on Monday, the day before her departure.

Calling climate change not just a public health and safety issue, but also one of the greatest economic challenges of the era, McCarthy acknowledged the fact that the US and China were the world's largest economies, energy consumers, and emitters of carbon pollution.

"One out of the three isn't that good. I'd rather not to be the largest energy consumers, or the largest emitter of carbon pollution. But since we are, we are going to have to get together and talk," she said, adding that she thought the two countries are well-positioned to begin work together in a new more concerted effort.

McCarthy cited a cooperative mechanism already in place between the EPA and the Ministry of Environmental Protection (MEP) in China.

"For the past 15 years, we have been working with them in depth on ways of addressing their air quality challenges. It is now very clear to China and to the US that actions must happen and must happen quickly in China," McCarthy said.

"I know that in the United States, for every dollar we have invested in the Clean Air Act, we have recouped four to eight dollars in economic benefits. If we can convince the Chinese that our continued relationship is worth that kind of investment, then we will all reap those benefits together," she said.

Given that China is now facing a similar public outcry of a deteriorating environment that had in the 1950s and 60s led to significant changes in the United States including the enactment of laws as well as the establishment of government infrastructures from local to state and to national levels, McCarthy said she hopes that China will learn from the US' experience.

"The US has faced these challenges, we have faced them well and we have faced them over time. We know the technologies that are available, we know what planning can do," she said.

"They have established some very ambitious goals not only for air quality, but also for climate," said McCarthy.

Air quality in Beijing has drastically deteriorated since the start of this year, and public attention to it culminated when the US Embassy in Beijing set up monitors that gave the general public real-time information about the density of PM2.5 — the tiny toxic particles that can become embedded in human lungs and may even lead to premature death.

"It was a motivating force as well as a significant opportunity to look at whether they have the governmental structure in place to be able to address this, and whether they know what available monitoring technologies should be," McCarthy said.

On climate change, McCarthy praised the agreement signed by the US President Obama and Chinese President Xi Jinping on tackling hydrofluorocarbons as "a good first-step commitment". In addition, she said her agency would remain committed to clean diesel, since much of the pollution in Beijing comes from diesel engines.

McCarthy said China is indispensible in a 2015 international agreement on climate change. "I think in a 2015 world, the two largest emitters of greenhouse gases need to be at the table, and I think it's extremely important that China be with us and be aggressive and supportive in establishing some goals that we can all be proud of," she said.