Video: Nitric acid cools the climate by influencing the formation of cloud droplets


When the air is thick with aerosols that act as condensation nuclei for cloud droplets, the number of cloud droplets increases and their size decreases. In this case, the clouds reflect more sunlight back to the space. Under certain circumstances, the nitric acid in the air improves the ability of the aerosols to act as cloud condensation nuclei and thus further increases the number of cloud droplets. First model results suggest that nitric acid has cooled the climate as much as changes in land use, or 0.2–0.4 W/m².

Interviewee: Research professor Ari Laaksonen, Finnish Meteorological Institute

Video length: 5:24 min

Language: Finnish, with English subtitles

Recorded: 6.5.2013

Published: 26.9.2013

Terms of use: The video is freely usable for non-commercial purposes, such as education. website and the producer of the video should be mentioned as reference.

For courses in Finnish upper secondary schools: BI3, GE3, KE1 (old) -> BI2, GE1, KE1 (new curriculum/OPS)

Filmed by: Riku Mesiniemi ja Anna Puustinen, Finnish Meteorological Institute

References: [1]

  • Makkonen, R., Romakkaniemi, S., Kokkola, H., Stier, P., Räisänen, P., Rast, S., Feichter, J., Kulmala, M. & Laaksonen, A. 2012. Brightening of the global cloud field by nitric acid and the associated radiative forcing. Atmospheric Chemistry and Physics. Volume 12, Number 16: 7625-7633


  • The content is produced as part of the TULUVAT project funded by the Finnish National Board of Education.