On Saturday evening, the negotiators for the United States, China, and the other countries that are party to the the UN climate convention reached agreement on the new architecture by which countries will cooperate to address climate change for 2020 and beyond. Prior to the meeting, known as COP21, all of the major emitting countries including the US, EU, China, India, and Brazil had set forth their 2025 or 2030 targets for reducing their emissions of the greenhouse gases that are rapidly changing our atmosphere, weather patterns, and land and ocean ecosystems. China committed for the first time to peak its CO2 emissions by 2030 and to make best efforts to peak earlier, and to increase its non-fossil energy to 20% of its energy consumption by 2030. It has also pledged to build a national carbon trading system to price carbon by 2017.

Under the new Paris Agreement, countries will revisit, review and strengthen their greenhouse gas emission reduction targets every 5 years, creating a virtuous cycle of commitments that become stronger as wind and solar energy prices fall and investment in renewable energy, electric vehicles and energy storage replace investments in fossil fuels and fossil-fuel based technologies. They will also report on their progress in meeting their climate commitments.

Some in the US who are opposed to taking action on climate change will criticize any agreement coming out Paris as as being unimplementable or weak, arguing that the US should not take actions to reduce its greenhouse gas emissions when other big emitters such as China can't be trusted to do the same. That argument is a cynical one aimed at delaying the inevitable transition of our societies from fossil fuels to clean energy. Here's why it isn't true:

1. Addressing climate change will help China to clean up its air. Severe air pollution has plagued large swathes of the country in the last several years, as power plants and factories powered by coal and millions of cars on the roads have brought choking pollution to its skies. At the beginning of the second week of the negotiations, after a week in which air pollution reached "beyond index" levels unimaginable in the United States, Beijing issued its first ever red alert for air pollution, taking half the cars off the roads and shutting down schools to try to clean up the air. There is broad recognition that China needs to reduce its coal consumption in order to both clean up its air and reduce its greenhouse gas emissions, since coal accounts for 50-60% of its fine particulate matter and 80% of its CO2 energy-related CO2 emissions. Similar air pollution levels have not been seen in the United States since the 1960s and 1970s, an era which saw the passage of the Clean Air Act and tough new fuel and tailpipe standards to clean up the choking smog in cities like Los Angeles. Just as the US cleaned up its air in response to the demands of its citizens, China is also self-motivated to cap its fossil fuel consumption and switch to cleaner energy in order to clean up its air and to ensure that the government is living up to citizens' expectations.

2. China is already meeting and exceeding its existing climate and clean energy targets. China is on track to meet and exceed its existing 2020 target to reduce its carbon intensity by 40-45% from 2005 levels. This is because its coal use fell by 2.9% in 2014 and nearly 5% so far this year, as its investments in clean energy begin to replace its long-term reliance on coal. The fall in China's coal consumption means that China's CO2 emissions were level in 2014 and are predicted to fall by 3.9% this year, the main factor in causing global CO2 emissions to stall or even fall this year. China has now installed more wind and solar power than any country in the world, and will install as much new solar power this year as currently installed across the entire United States. In fact, Chinese investments in renewable energy topped $83 billion in 2014, more than double that of the United States, and it plans to increase wind and solar energy to 200 GW and 100 GW respectively by 2020, further increasing its lead as a renewables superpower. Doing so will both help to clean up China's air and re-direct its economy toward a more sustainable pathway, while also spurring jobs and innovation.

3. China is building a strong energy and GHG emissions measurement, reporting and verification system. China has established a mandatory GHG reporting system for industrial enterprises to measure and report their greenhouse gas emissions in 24 key industries. As it prepares to establish a national carbon trading system in 2017, it will be requiring enterprises to report their emissions and to have them verified by third party verification companies. Ensuring strong MRV will be important for China to ensure the success of its carbon trading system, and in fact China is seeking to learn how to improve its emissions tracking through close cooperation with counterparts in California and the EPA. China has also been improving its energy statistics reporting, releasing updated coal consumption statistics for the period 2000 to 2013 which, while they were an increase compared to previously reported figures, also show that China is working hard to make its energy statistics as accurate as possible.

4. China is strengthening environmental enforcement. As part of its war on pollution,China has implemented a much tougher Environmental Protection Law, with stronger penalties, official performance assessments, public interest lawsuits and pollution data monitoring to enforce pollution standards. These powerful new tools are a game changer and give the government much greater authority to regulate and punish polluters, and they reflect the government's recognition that providing clean air and water to its citizens requires strict compliance with environmental regulations.

5. China is investing $3.1 billion of its own money to help developing countries address climate change. China's is investing $3.1 billion to help developing countries tackle climate change through its South-South Cooperation Fund. These efforts demonstrate China's recognition of the seriousness of climate change and a willingness to do its part to help the most vulnerable countries adapt to the effects of climate change and build more resilient, low carbon communities.

For too long, climate naysayers in the United States have used the specter of a rapidly developing China to argue for inaction. The time for making such arguments has now passed, as China and other developing countries forge ahead in reducing their emissions and investing in clean energy in order to clean up their own environment and build the foundation for a sustainable and healthy future for their people.