BEIJING — The United States and China are the world’s two largest economies, two largest consumers of energy, and two largest emitters of greenhouse gases. Together we account for about 40 percent of the world’s emissions. 
 
 We need to solve this problem together because neither one of us can solve it alone. Even if the United States somehow eliminated all of our domestic greenhouse gas emissions, it still wouldn’t be enough to counteract the carbon pollution coming from China and the rest of the world. Likewise, even if China went down to zero emissions, it wouldn’t make enough of a difference if the United States and the rest of the world didn’t change direction. 
 
 That’s the reality of what we’re up against. That’s why it matters that the world’s most consequential relationship has just produced something of great consequence in the fight against climate change. 
 
 Today, President Obama and Chinese President Xi Jinping are jointly announcing targets to reduce carbon emissions in the post-2020 period. By doing this – together, and well before the deadline established by the international community – we are encouraging other countries to put forward their own ambitious emissions reduction targets soon and to overcome traditional divisions so we can conclude a strong global climate agreement in 2015. 
 
 Our announcement can inject momentum into the global climate negotiations, which resume in less than three weeks in Lima, Peru, and culminate next year in Paris. The commitment of both presidents to take ambitious action in our own countries, and work closely to remove obstacles on the road to Paris, sends an important signal that we must get this agreement done, that we can get it done, and that we will get it done. 
 
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 This is also a milestone in the United States-China relationship, the outcome of a concerted effort that began last year in Beijing, when State Councilor Yang Jiechi and I started the United States-China Climate Change Working Group. It was an effort inspired not just by our shared concern about the impact of climate change, but by our belief that the world’s largest economies, energy consumers and carbon emitters have a responsibility to lead. 
 
 The targets themselves are also important. Ambitious action by our countries together is the foundation to build the low-carbon global economy needed to combat climate change. The United States intends to reduce net greenhouse gas emissions by 26 to 28 percent below 2005 levels by 2025 – a target that is both ambitious and feasible. It roughly doubles the pace of carbon reductions in the period from 2020 to 2025 as compared to the period from 2005 to 2020. It puts us on a path to transform our economy, with emissions reductions on the order of 80 percent by 2050. It is grounded in an extensive analysis of the potential to reduce emissions in all sectors of our economy, with significant added benefits for health, clean air, and energy security. 
 
 Our target builds on the ambitious goal President Obama set in 2009 to cut emissions in the range of 17 percent below 2005 levels by 2020. We are on track to meet that goal, while creating jobs and growing the economy, with the help of a burgeoning clean energy sector. Since the president took office, wind energy production has tripled and solar energy has increased by a factor of ten. This summer, the Environmental Protection Agency proposed the first carbon pollution standards for existing power plants, which account for a third of United States carbon pollution. 
 
 The Chinese targets also represent a major advance. For the first time China is announcing a peak year for its carbon emissions – around 2030 – along with a commitment to try to reach the peak earlier. That matters because over the past 15 years, China has accounted for roughly 60 percent of the growth in carbon dioxide emissions world-wide. We are confident that China can and will reach peak emissions before 2030, in light of President Xi’s commitments to restructure the economy, dramatically reduce air pollution and stimulate an energy revolution. 
 
 China is also announcing today that it would expand the share of total energy consumption coming from zero-emission sources (renewable and nuclear energy) to around 20 percent by 2030, sending a powerful signal to investors and energy markets around the world and helping accelerate the global transition to clean-energy economies. To meet its goal, China will need to deploy an additional 800 to 1,000 gigawatts of nuclear, wind, solar and other renewable generation capacity by 2030 – an enormous amount, about the same as all the coal-fired power plants in China today, and nearly as much as the total electricity generation capacity of the United States. 
 
 There is no question that all of us will need to do more to push toward the de-carbonization of the global economy. But in climate diplomacy, as in life, you have to start at the beginning, and this breakthrough marks a fresh beginning. Two countries regarded for 20 years as the leaders of opposing camps in climate negotiations have come together to find common ground, determined to make lasting progress on an unprecedented global challenge. Let’s ensure that this is the first step toward a world that is more prosperous and more secure. ||||| The United States and China are pledging to move faster to reduce or limit emissions of heat-trapping gases blamed for global warming. China and the U.S. are the world's two largest polluters, and by taking action together, leaders from both countries hope to spur other nations to be equally aggressive as they work to finalize a worldwide climate treaty next year. 
 
 What both countries are announcing, according to the White House: 
 
 UNITED STATES 
 
 —Reduce U.S. greenhouse gas emissions by 26 percent to 28 percent by the year 2025, compared to what the U.S. was emitting in 2005. Previously, Obama had committed to cutting emissions by 17 percent by 2020 compared to 2005 levels, and officials say the U.S. is on track to meet that goal. 
 
 —Double the rate at which the U.S. is reducing its emissions per year. Between 2005 and 2020, the U.S. on average must cut emissions 1.2 percent per year to meet Obama's overall goal of 17 percent. Over the five years between 2020 and 2025, the U.S. aims to reduce emissions and average of 2.3 percent to 2.8 percent per year. 
 
 —Submit the new 2025 emissions reduction target by the end of the first quarter of 2015 as the intended U.S. contribution to the U.N. Framework Convention on Climate Change, the treaty that nations hope to finalize later in 2015 in Paris. 
 
 CHINA 
 
 —Set a target for carbon dioxide emissions to peak by around 2030, with the goal of topping out earlier if possible. 
 
 —Expand the share of China's energy consumption derived from zero-emission sources to about 20 percent by 2030. The U.S. says that would require China to develop up to 1,000 gigawatts of new power from sources like nuclear, wind and solar.
– The US and China rank as the world's two largest polluters, but a surprise deal is turning them into the world's two largest pollution fighters: The nations announced that they'll be working in tandem on long-term greenhouse-gas controls that would cut emissions by nearly a third over the next 15 years or so, CNN reports. "As the world's two largest economies, energy consumers, and emitters of greenhouse gases, we have a special responsibility to lead the global effort against climate change," President Obama said in a joint press conference with Chinese President Xi Jinping today at the end of the APEC summit. The move, which was months in the making, came as a surprise to experts expecting a much more limited scope, the Wall Street Journal reports. Calling it a "game changer," Mother Jones notes that it could heavily influence next year's climate talks in Paris. Key mandates include the US reducing emissions by 26% to 28% by the year 2025 (compared to the year 2005), as well as doubling the rate of emissions reduction each year between 2020 and 2025 to an average 2.3% to 2.8%, the AP reports. China is pledging to stop increasing emissions by 2030 (even earlier, if possible), as well as increase energy from zero-emission sources such as wind, solar, and nuclear to 20% by 2030. Although some worry about recent GOP gains in government as a possible roadblock, a senior administration official tells CNN that "we believe we can proceed with the authority we already have." Secretary of State John Kerry writes in a New York Times op-ed that "this is … a milestone in the United States-China relationship," a "fresh beginning," and "the first step toward a world that is more prosperous and more secure."