Each balloon is fitted with the latest meteorological technology and GPS tracking systems which allow progress to be tracked online.

BBC: David Hempleman-Adams' gas balloon 'flying well' in race

Today, hundreds of floats deployed under the Global Ocean Observing System (GOOS), coordinated by UNESCO and largely supported by the Japan Meteorological Agency (JMA) and Japan Agency for Marine-Earth Science and Technology (JAMSTEC), are used to measure ocean temperature, salinity and tsunami risk.

UNESCO: OFFICE IN DAKAR

Dr Harries was president of the UK's Royal Meteorological Society from 1996 to 1997, and is a former director of projects and technology at the British National Space Centre.

BBC: UK scientists see greenhouse evidence