January is the month for making, and by now often breaking, New Year resolutions. For those of us whose pledges extend only to flaky self improvement such as taking more exercise, their breaking is of little import. But we expect better of others. As the days lengthen, hope triumphs over experience. Maybe Gordon Brown’s new enthusiasm for preventive health will pay somedividend. Maybe the recent deal in Bali will accelerate the global response to climate change.

On the exercise front, we can be sure that there is one cohort who will have kept their resolutions. For aspiring participants of this year’s Olympic Games in Beijing it is now only six months before years of hard training are put to the test. Whether new world records will be set is under debate—for reasons that underline the link between climate change and health.

Among the already extensive media coverage of the games, comment about Beijing’s poor air quality has been as prominent as …