Met office research suggests man-made aerosols and industrial pollution may have impacted on the number of Atlantic hurricanes during the 20th Century
Poor air pollution may be responsible for reducing the number of Atlantic hurricanes during the 20th Century, according to UK Met Office research.
Furthermore, the research suggests that air pollution in the form of man-made aerosol particles which include smoke, smog and air pollution from the likes of factory chimneys, vehicle exhausts and power stations may have controlled decade-to-decade changes in the number of hurricanes.
In a paper published in the journal Nature Geoscience this week (June 24), Met Office researchers found that man-made aerosol particles make clouds brighter, causing them to reflect more energy from the sun back into space. This impacts ocean temperatures and tropical circulation patterns, effectively making conditions less favourable for hurricanes.
Lead author of the research Dr Nick Dunstone, a Met Office climate prediction scientist, said: Industrial emissions from America and Europe over the 20th Century have cooled the North Atlantic relative to other regions of the ocean. Our research suggests that this alters tropical atmosphere circulation – making it less likely that hurricanes will form.
He said that since the introduction of the clean air-acts in the 1980s, concentrations of aerosols over the North Atlantic have reduced and that model results suggest this has contributed to recent increases in hurricane numbers.
He added: On the other hand, the reduction in aerosols has been beneficial for human health and has been linked to the recovery of Sahel rains since the devastating drought in the 1980s.
According to the Met Office, it has long been known that North Atlantic hurricane activity has distinct long-timescale variability.
Dr Doug Smith, a Met Office research fellow and co-author of the study, said: We saw relatively quiet periods between 1900-20 and then again from 1970-80, and active periods between 1930-60 and since 1995. On average, active periods have 40% more hurricanes.
However, the Met Office said that while the research suggests that hurricane occurrences over the next 20 years could depend on future air pollution, more international collaborative research was still needed on the issue because modelling the impact of aerosols is one of the largest uncertainties in climate science.
Co-author of the study Dr Ben Booth, a Met Office climate processes scientist, said: This study, together with work we published last year, suggests that there may be a greater role than previously thought for man-made influence on regional climate changes that have profound impacts on society.