How clouds form is one of the natural processes we thought we’d cracked. It seems so simple. First, water vapour sticks to tiny particles such as salt and dust, known as aerosols, high up in the atmosphere. Then bigger droplets form, and when these stick together, clouds are produced. The trouble is, recent research is showing that tiny organisms floating in the atmosphere – bacteria, to be exact – can act as what meteorologists refer to as ‘cloud condensation nuclei’. These are the particles around which water droplets and ice crystals, another component of clouds, form. These bacteria can therefore have a profound effect on our weather.
“Recent research is showing
