BEIJING - The United States and China on Wednesday announced an action plan on greenhouse emissions as part of a "historic" pact that was acclaimed by climate scientists.

At a Beijing summit, the leaders of the world's two biggest economies put their stamp on attempts to breathe new life into action against global warming ahead of international talks in Paris next year.

US President Barack Obama said the joint announcement on the two countries' emissions targets was a "historic agreement" and a "major milestone in the US-China relationship".

President Xi Jinping said: "We agreed to make sure that international climate change negotiations will reach an agreement in Paris."

In the action plan, China sets a target for its greenhouse gas output to peak "around 2030", and intends to increase the share of non-fossil fuels in primary energy consumption to around 20% by 2030.

And Obama, who faces skepticism as well as outright denial about climate change in the US Congress, set a goal for the United States to cut its own emissions of greenhouse gases by 26 to 28 percent from 2005 levels by 2025.

Both countries agreed to launching a Climate-Smart/Low-Carbon Cities Initiative.

As a first step, China and the US will convene a Climate-Smart/ Low-Carbon Cities Summit where leading cities from both countries can share best practices, set new goals and celebrate city-level leadership in reducing carbon emissions and building resilience, according to the action plan.

"We have a special responsibility to lead the worldwide effort against climate change," Obama said at a joint news conference with Xi. "We hope to encourage all economies to be more ambitious," he added.

China and the US, which together produce around 45 percent of the world's carbon dioxide, will be key to ensuring a global deal on reducing emissions after 2020 is reached next year. The World Resources Institute, a US-based environmental group, hailed the Obama-Xi pact as a breakthrough.

"It's a new day to have the leaders of the US and China stand shoulder-to-shoulder and make significant commitments to curb their country's emissions," the institute's president Andrew Steer said in a statement.

"They have both clearly acknowledged the mounting threat of climate change and the urgency of action," he said.

The European Union pledged last month to reduce emissions by at least 40 percent by 2030 compared with 1990 levels.

The EU accounts for 11 percent of the world's greenhouse gas emissions, compared to 16 percent for the United States and 29 percent for China.

The full text of the agreement on climate changes is as follows.

China-US Joint Announcement on Climate Change

Beijing, China, 12 November 2014

1. The People's Republic of China and the United States of America have a critical role to play in combating global climate change, one of the greatest threats facing humanity. The seriousness of the challenge calls upon the two sides to work constructively together for the common good.

2. To this end, President Xi Jinping and President Barack Obama reaffirmed the importance of strengthening bilateral cooperation on climate change and will work together, and with other countries, to adopt a protocol, another legal instrument or an agreed outcome with legal force under the Convention applicable to all Parties at the United Nations Climate Conference in Paris in 2015. They are committed to reaching an ambitious 2015 agreement that reflects the principle of common but differentiated responsibilities and respective capabilities, in light of different national circumstances.

3. Today, the Presidents of China and the United States announced their respective post-2020 actions on climate change, recognizing that these actions are part of the longer range effort to transition to low-carbon economies, mindful of the global temperature goal of 2℃. The United States intends to achieve an economy-wide target of reducing its emissions by 26%-28% below its 2005 level in 2025 and to make best efforts to reduce its emissions by 28%. China intends to achieve the peaking of CO2 emissions around 2030 and to make best efforts to peak early and intends to increase the share of non-fossil fuels in primary energy consumption to around 20% by 2030. Both sides intend to continue to work to increase ambition over time.

4. China and the United States hope that by announcing these targets now, they can inject momentum into the global climate negotiations and inspire other countries to join in coming forward with ambitious actions as soon as possible, preferably by the first quarter of 2015. The two Presidents resolved to work closely together over the next year to address major impediments to reaching a successful global climate agreement in Paris.

5. The global scientific community has made clear that human activity is already changing the world’s climate system. Accelerating climate change has caused serious impacts. Higher temperatures and extreme weather events are damaging food production, rising sea levels and more damaging storms are putting our coastal cities increasingly at risk and the impacts of climate change are already harming economies around the world, including those of China and the United States. These developments urgently require enhanced actions to tackle the challenge.

6. At the same time, economic evidence makes increasingly clear that smart action on climate change now can drive innovation, strengthen economic growth and bring broad benefits – from sustainable development to increased energy security, improved public health and a better quality of life. Tackling climate change will also strengthen national and international security.

7. Technological innovation is essential for reducing the cost of current mitigation technologies, leading to the invention and dissemination of new zero and low-carbon technologies and enhancing the capacity of countries to reduce their emissions. China and the United States are two of the world’s largest investors in clean energy and already have a robust program of energy technology cooperation. The two sides have, among other things:

  a. established the China-U.S. Climate Change Working Group (CCWG), under which they have launched action initiatives on vehicles, smart grids, carbon capture, utilization and storage, energy efficiency, greenhouse gas data management, forests and industrial boilers;

  b. agreed to work together towards the global phase down of hydrofluorocarbons (HFCs), very potent greenhouse gases; 

  c. created the China-U.S. Clean Energy Research Center, which facilitates collaborative work in carbon capture and storage technologies, energy efficiency in buildings, and clean vehicles; and 

  agreed on a joint peer review of inefficient fossil fuel subsidies under the G-20.

8. The two sides intend to continue strengthening their policy dialogue and practical cooperation, including cooperation on advanced coal technologies, nuclear energy, shale gas and renewable energy, which will help optimize the energy mix and reduce emissions, including from coal, in both countries. To further support achieving their ambitious climate goals, today the two sides announced additional measures to strengthen and expand their cooperation, using the existing vehicles, in particular the China-U.S. Climate Change Working Group, the China-U.S. Clean Energy Research Center and the China-U.S. Strategic and Economic Dialogue. These include:

Expanding Joint Clean Energy Research and Development: A renewed commitment to the China-U.S. Clean Energy Research Center, including continued funding for three existing tracks on building efficiency, clean vehicles and advanced coal technology and launching a new track on the energy-water nexus; 

Advancing Major Carbon Capture, Utilization and Storage Demonstrations: Establishment of a major new carbon storage project based in China through an international public-private consortium led by China and the United States to intensively study and monitor carbon storage using industrial CO2 and also work together on a new Enhanced Water Recovery (EWR) pilot project to produce fresh water from CO2 injection into deep saline aquifers; 

Enhancing Cooperation on HFCs: Building on the historic Sunnylands agreement between President Xi and President Obama regarding HFCs, highly potent greenhouse gases, the two sides will enhance bilateral cooperation to begin phasing-down the use of high global warming potential HFCs and work together in a multilateral context as agreed by the two Presidents at their meeting in St. Petersburg on 6 September 2013; 

Launching a Climate-Smart/Low-Carbon Cities Initiative: In response to growing urbanization and increasingly significant greenhouse gas emissions from cities and recognizing the potential for local leaders to undertake significant climate action, China and the United States will establish a new initiative on Climate-Smart/Low-Carbon Cities under the CCWG. As a first step, China and the United States will convene a Climate-Smart/ Low-Carbon Cities Summit where leading cities from both countries will share best practices, set new goals and celebrate city-level leadership in reducing carbon emissions and building resilience; 

Promoting Trade in Green Goods: Encouraging bilateral trade in sustainable environmental goods and clean energy technologies, including through a U.S. trade mission led by Secretaries Moniz and Pritzker in April 2015 that will focus on smart low-carbon cities and smart low-carbon growth technologies; and 

Demonstrating Clean Energy on the Ground: Additional pilot programs, feasibility studies and other collaborative projects in the areas of building efficiency, boiler efficiency, solar energy and smart grids.