BEIJING, Sept. 4 (Xinhua) -- The international community has welcomed the ratification of the Paris Agreement by the world's two largest economies on Saturday, lauding the move as an important step toward the deal's early entry into force and for the battle against global warming.
In a meeting between Chinese President Xi Jinping, U.S. President Barack Obama and U.N. Secretary-General Ban Ki-Moon on the eve of the G20 Hangzhou summit scheduled for Sunday and Monday, both China and the United States formally joined the climate change agreement.
French President Francois Hollande on his Facebook account hailed the ratification as an "important step" by the two biggest carbon emitters, and said it opened the way for the agreement's entry into force at the end of the year.
Depositing the documents together, China and the United States have displayed their ambition and determination to jointly tackle a global challenge, Xi said after depositing the ratification documents to the United Nations. The handover of the legal document is evidence of China's solemn commitment, he added.
"Just as I believe the Paris Agreement will ultimately prove to be the turning point for our planet, I believe history will judge today's efforts as pivotal," Obama said in the presence of Xi and Ban.
Nathaniel Keohane, vice president of Global Climate at Environmental Defense Fund, said in an interview with Xinhua, "Continued global momentum on climate action depends on strong leadership by the United States and China, the world's top two emitters, by a large margin."
"Today's joint announcement represents important progress, but also highlights where continued leadership will be critical," Keohane said.
On Dec. 12, 2015, after hard and lengthy bargaining, climate negotiators of 196 parties to the U.N. conference on climate change in Paris sealed the climate change pact, aiming to reverse the trend of temperature rises mainly caused by carbon emissions.
"Nearly two years ago, the early announcement of emissions reduction targets by China and the United States helped to catalyze broad support for the landmark Paris climate agreement adopted in December 2015," Keohane said.
Keohane made the remarks in reference to a joint climate change agreement issued by Beijing and Washington in November 2014, in which Washington set new targets of reducing its emissions and Beijing pledged to achieve the peaking of carbon dioxide emissions by around 2030.
"Today's action will play a similar role, as U.S.-China leadership inspires other countries to formally join the agreement and do their part to ensure that it enters into force this year," he noted.
"With the United States and China together accounting for nearly 40 percent of global greenhouse gas emissions, the world just got much closer to the 55-percent threshold necessary for the agreement to take effect," he added.
The ratification of the Paris Agreement "hailed their (China and the U.S.) new era of climate cooperation as the best chance for saving the planet," the Associated Press commented Saturday in an article.
Setting aside their cyber and maritime disputes, the two countries cemented their partnership on climate change and offered "a rare display of harmony," commented The New York Times.
United Nations climate chief Patricia Espinosa said in a statement that, by ratifying the agreement, China and the United States open up avenue for the world's sustainable development, and bring the historic global climate deal a big step closer to its entry into force.
Civil aviation is one of the world's fastest-growing sources of carbon pollution.
Both China and the United States on Saturday pledged support for the Assembly of the International Civil Aviation Organization (ICAO) to reach consensus on a global market-based measure to address carbon emissions from international aviation.
"A market-based measure to cap aviation emissions from 2020 could prevent 8 billion tons of emissions in the first two decades alone, but only if the agreement covers a sufficient share of the growth in global emissions," Keohane noted.
The two countries' leading commitments to the ICAO deal, along with China's indication of early participation, is "a good start toward closing the gap between the aviation industry's future growth and what's necessary to avoid the worst effects of a warming climate," he said.
"Participation by China as well as other countries with significant aviation footprints, such as Japan, Singapore, the United Arab Emirates and Brazil, will be crucial to ensuring environmental integrity and avoiding market-distorting loopholes," he said.
Ratifying the agreement was in some ways "a natual desicion" for China, a number of experts were cited by Los Angeles Times as saying. The agreement is in line with the country's domestic effort to clean up its air pollution and lends its leaders international prestige, it added.
The experts agree that China is likely to live on its promises.