Skip to Content
Climate change and energy

Chinese factories are producing banned chemicals that could delay ozone recovery

June 25, 2018

A study published last month found that atmospheric levels of ozone-damaging chlorofluorocarbons were unexpectedly rising again, hatching a scientific mystery over who was producing chemicals that were outlawed years ago.

The culprit? The New York Times reports that one major source appears to be Chinese factories that have continued to use CFC-11 to produce foam insulation, citing “interviews, documents, and advertisements” collected by it and independent investigators, including the Environmental Investigation Agency. Several sources in the piece emphasized that there could be illegal production elsewhere as well.

Why does that matter? The Montreal Protocol, completed in 1987, phased out production of CFC-11 and related chemicals in an effort to repair the ozone layer, which blocks harmful ultraviolet radiation. CFC-11 has been banned since 2010. The agreement is considered a landmark victory in international environmental diplomacy, providing a template for coordinated action on an issue of global consequence. CFCs are also potent greenhouse gases that contribute to global warming.

The episode underscores the challenges of enforcing an international treaty in all corners of the world. The Nature study last month found that the rogue emissions could delay the recovery of the ozone layer by a decade. Erik Solheim, head of the United Nations Environment Program, told the Times the ongoing CFC-11 production was “nothing short of an environment crime which demands decisive action.” 

Deep Dive

Climate change and energy

This classic game is taking on climate change

What the New Energies edition of Catan says about climate technology today.

How battery-swap networks are preventing emergency blackouts

When an earthquake rocked Taiwan, hundreds of Gogoro’s battery-swap stations automatically stopped drawing electricity to stabilize the grid.

The world’s on the verge of a carbon storage boom

Hundreds of looming projects will force communities to weigh the climate claims and environmental risks of capturing, moving, and storing carbon dioxide.

The cost of building the perfect wave

The growing business of surf pools wants to bring the ocean experience inland. But with many planned for areas facing water scarcity, who bears the cost?

Stay connected

Illustration by Rose Wong

Get the latest updates from
MIT Technology Review

Discover special offers, top stories, upcoming events, and more.

Thank you for submitting your email!

Explore more newsletters

It looks like something went wrong.

We’re having trouble saving your preferences. Try refreshing this page and updating them one more time. If you continue to get this message, reach out to us at with a list of newsletters you’d like to receive.