The protocol gave investors a shared deadline: within that time, a way had to be found to make refrigerants without destroying the ozone layer. So, investors redirected their research and development funding wholesale. Developed countries had stopped producing CFCs by around 1996, and developing countries followed suit by 2010. That is how an entire industry changed course. The replacements, of course, had unexpected side effects of their own. HFCs, which later became widespread, don't harm the ozone layer, but they are potent greenhouse gases. Yet precisely because this system still allowed for accountability and could still call a halt, in 2016 countries adopted the Kigali Amendment and began phasing down HFCs.