As Chinese President Hu Jintao and Chinese diplomats sat in a spacious hall in Beijing over the weekend to discuss diplomatic projects, they sacrificed the formality of suits and ties in favor of white dress shirts to better weather the warm temperatures inside the building -- a measure taken to help conserve energy.

The temperature in the room is set automatically to 26 degrees Celsius, or Fahrenheit 79, so the usual attire would make for a sweaty mission.

Two years ago, the Chinese cabinet regulated the lowest indoor temperature in all public venues during the summer to save energy, with the rare exception of diplomatic occasions or grand state ceremonies.

Premier Wen Jiabao met last week with U.S. Energy Secretary Steven Chu and Commerce Secretary Gary Locke, who were in China to advance bilateral cooperation on clean energy and energy efficiency technologies.

Wen's deputy, Vice Premier Li Keqiang told Secretary Chu, a Nobel laureate who is an avid advocate for clean energy, that China adhered to the principle of "common but differentiated responsibilities" as it actively responds to global climate change.

"Common but differentiated responsibilities" refers to the responsibilities of both developed and developing countries in reducing their carbon footprints respective to their developmental abilities.

The United Nations Framework Convention on Climate Change (UNFCCC) notes "that the largest share of historical and current global emissions of greenhouse gases has originated in developed countries, that per capita emissions in developing countries are still relatively low and that the share of global emissions originating in developing countries will grow to meet their social and development needs."

The UNFCCC was signed by more than 150 countries at the Rio Earth Summit in 1992 and was approved by at least 192 countries.

George Washington University law professor David Freestone, who retired six months ago from the World Bank as a senior adviser and deputy general counsel, said in an e-mail interview with Xinhua, "I do not see it (the principle) as outdated."

Prof. Robert Stavins at Harvard's John F. Kennedy School of Government also wrote to Xinhua, "The central feature of the principle is (that) all countries should be involved in addressing climate change, their burden in addressing climate change need not be the same, and their relative burdens could be related to their stage of economic development."

Data from the National Development and Reform Commission (NDRC) showed from 1950 to 2000 greenhouse gas emissions from industrialized countries accounted for 77 percent of the world total while China contributed about nine percent.

Between 1850 and 2005, the U.S. emitted 27 percent of the world's total carbon dioxide, Russia and China both eight percent, Germany seven percent, the United Kingdom six percent, Japan four percent and India two percent, according to the Global Environment and Energy in the 21st Century, or GEE-21, a Honolulu, Hawaii-based nonprofit organization that conducts research and educational activities dealing with issues of resource management and environment.

Even though China's per capita carbon dioxide emissions were about only one-fifth of those in the United States, the 1.3-billion population and the rapidly-growing economy makes China the second largest emitter next to the U.S.