2. China-US cooperation made a major difference in COP21.

On Dec 13th, President Barack Obama made a televised speech about the success of UN Conference on Climate Change in Paris(COP21). He pointed out that "thanks to US-China cooperation", COP21 achieved a major agreement. The same day President Xi Jinping and President Obama had a telephone conversation to congratulate each other for this important achievement.

This is the first time that China and the US cooperated closely to make the UN climate change conference successful. The success of COP21 is the most important good news in 2015.

Climate change poses a formidable challenge to mankind in the 21st century. No country, no matter how powerful it is, is able to meet this challenge alone. Humanity has no alternative but to unite to meet this challenge. Otherwise, the survival of human race would be at stake.

In December 2009, the United Nations Climate Change conference in Copenhagen failed to reach an agreement to the total disappointment of the international community. One of the reasons of Copenhagen Conference's failure was China-US disagreement on a number of issues. After Copenhagen, China and the US engaged in frequent exchanges of views on climate change and made some progress. Especially in November 2014 when President Obama paid a state visit to China, the two leaders issued a joint statement on climate change. It was well received by the international community. It made people hopeful that the deadlocked UN climate change talks may move forward. In December 2014, UN climate change talks were held at the ministerial level in Peru. After many days of negotiations, the parties concerned were still unable to reach an agreement. Finally, they agreed to borrow the wording of the American and Chinese Presidents' Joint Statement on Climate Change to break the deadlock.

In September 2015, President Xi Jinping paid a state visit to the US. He had nine hours of conversation with President Obama. The two presidents issued a second joint statement on climate change, which paved the way to the successful conclusion of COP21.

On December 11th, at the final stage of COP21, President Xi and President Obama had a telephone conversation. Both sides pledged to cooperate closely to assure the success of COP21.

Sino-American successful cooperation on climate change is a milestone not only in China-US relations but also in international relations. The importance of this success cannot be overstated.

For China-US relationship, the past 44 years since Dr. Henry Kissinger's first visit to China in July 1971 can be divided into three phases.

In the first phase (1971-1991), China-US relations were founded on common opposition to Soviet hegemony.

In the second phase (1992-2013), economic and trade cooperation served as the pillar of China-US relations. In 1991, China-US bilateral trade amounted only to 25.3 billion US dollars. In 2013, the figure went up to 521 billion US dollars.

In the third phase, starting from 2013, China-US relations were supported by three pillars: a. joint efforts to deal with global challenges; b. all round bilateral cooperation; c. military and security cooperation.

At COP21, China-US cooperation made crucial contribution to the success of conference. This has opened the way for future cooperation between the two countries in this important area.

For the international relations, China-US successful cooperation is a shining example to show how mutual cooperation can make a difference.

In the Cold War era, the US and the Soviet Union had the last say on major international issues. After the collapse of the Soviet Union, the US became the only superpower. The US and its western allies had the last say on major international issues. The 21st century has witnessed the most important change in international relations -- the rise of emerging countries. China is one of them. The rise of emerging countries represents a major power shift. However, in international relations, the voice of emerging countries and developing countries was still not loud enough. Then came COP21. China and other emerging and developing countries, through mutual coordination and consultation, made significant contribution to the success of the Conference. This marks a milestone for international relations and has far-reaching consequences.