For many, ozone is an environmental issue that was resolved by the worldwide banning of CFCs. While the ozone hole over Antarctica may no longer be expanding, ground-level ozone, created by chemical reactions between nitrous oxides (e.g. from auto exhaust) and volatile organic compounds in the presence of sunlight and humidity, remains a serious problem, damaging human respiratory systems, crops, and ecosystems, as well as contributing to global warming. And it's capable of traveling long distances from its source - e.g. ozone emitted in China has been found to impact air quality as far away as California.
In short, it's a global problem, but to date there is no global system set up to measure and monitor ground-level ozone - on vast swaths of the planet, there is no measurement of ground-level ozone at all. The Global Ozone Project (a.k.a. GO3), an educational outreach project launched by 2B Technologies, a leading manufacturer of ozone monitors used by NOAA, EPA, and other government agencies, is aiming to change that.