To ask the Secretary of State for Transport what action he is taking to reduce the amount of chemical trails from aircraft in UK airspace; and if he will make a statement. (111303)

I assume the hon. Member is referring to contrails. ‘Contrails’, which are ice crystal clouds that form at high altitudes from the exhaust products of aircraft but only when atmospheric conditions of temperature and humidity favour this. There are many uncertainties in this area and the Department is sponsoring research to reduce these and UK scientists are actively engaged in international research in this topic. The Department sponsored a major international scientific meeting last year which presented significant new research on the subject:

http://www.pa.op.dir.de/tac/