ozone layer

The train is not a complete answer to transportation emissions, but it shows what can happen when local geography and thoughtful engineering work together.

And then there is the ozone layer, one of the clearest examples of patient global action producing measurable environmental recovery.

The ozone hole over Antarctica was smaller in 2025 than it has been in most years since the early 1990s, according to the World Meteorological Organization.

Scientists attribute the law long-term recovery to the Montreal Protocol, the international agreement that phased out chemicals known to damage the ozone layer.

The ozone layer is not fully recovered yet, and the work will continue for decades.

But the direction matters.

This is a global problem moving in the right direction because countries stayed with a shared solution.