Christopher Booker:

In early March, NASA released some startling satellite images comparing nitrogen dioxide levels in China before and after the coronavirus lockdown. The first, compiled between January 1 and January 20, shows the world's second largest economy, chugging away at full steam. The second, compiled from February 10 to February 25, shows that same economy in a near standstill.

The reduction in nitrogen dioxide — the noxious gas that comes from cars, power plants and industrial facilities — was dramatic. Suddenly the choking air of major cities became easier to breathe.

As other countries have hunkered down, does the slowing of emissions also portend a respite for global climate change? Those who have built careers studying and analyzing the atmosphere say… well, maybe.