With the snow line edging higher, 186 French ski resorts have shut, while global heating threatens dozens more

When Céüze 2000 ski resort closed at the end of the season in 2018, the workers assumed they would be back the following winter. Maps of the pistes were left stacked beside a stapler; the staff rota pinned to the wall.

Six years on, a yellowing newspaper dated 8 March 2018 sits folded on its side, as if someone has just flicked through it during a quiet spell. A half-drunk bottle of water remains on the table.

Secondhand tobacco smoke and routine tasks such as operating the stove shown to be biggest emitters of indoor pollution in UK homes

Christmas and New Year is a time when many people will be at home. Being indoors can give us a degree of protection from outdoor air pollution, but it can also trap pollution we produce inside our homes.

Risks from secondhand tobacco smoke are well known and the effect is perhaps best seen by comparison of health data before and after indoor smoking bans. A study of 47 indoor smoking bans in public spaces found hospital admissions for heart attacks decreased by an average of 12%, but people are less aware of other indoor pollutants and how to minimise them.