Kate Willett is a Met Office scientist and author of a new study looking at global humidity – the amount of water vapour held in the atmosphere as a gas.
She said: “Think of climate change and people immediately think of rising temperatures. This isn’t wrong, but it misses a key fact that climate change is also causing shifts in humidity.
“Humidity governs the increasing likelihood of heavier rainfall and more dangerous heatwaves. We need to monitor and understand changes in surface humidity, just like temperature. Working together humidity and temperature can be thought of as the twin pillars of climate change.”
The study – published today in the journal Earth System Science Data – highlighted an interesting paradox: although the amount of water vapour in the atmosphere has increased – as expected – it hasn’t increased by as much as it could have done. Kate Willett explained: “Specific humidity, the amount of water vapour in the air, has increased – this is consistent with theoretical expectation for a warming world – the air has warmed so it can and does hold more water vapour.