Warming-induced increase in aerosol number concentration likely to moderate climate change
* Pauli Paasonen<http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo1800.html#auth-1>, * Ari Asmi<http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo1800.html#auth-2>, * Tuukka Petäjä<http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo1800.html#auth-3>, * Maija K. Kajos<http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo1800.html#auth-4>, * Mikko Äijälä<http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo1800.html#auth-5>, * Heikki Junninen<http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo1800.html#auth-6>, * Thomas Holst<http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo1800.html#auth-7>, * Jonathan P. D. Abbatt<http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo1800.html#auth-8>, * Almut Arneth<http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo1800.html#auth-9>, * Wolfram Birmili<http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo1800.html#auth-10>, * Hugo Denier van der Gon<http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo1800.html#auth-11>, * Amar Hamed<http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo1800.html#auth-12>, * András Hoffer<http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo1800.html#auth-13>, * Lauri Laakso<http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo1800.html#auth-14>, * Ari Laaksonen<http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo1800.html#auth-15>, * W. Richard Leaitch<http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo1800.html#auth-16>, * Christian Plass-Dülmer<http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo1800.html#auth-17>, * Sara C. Pryor<http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo1800.html#auth-18>, * Petri Räisänen<http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo1800.html#auth-19>, * Erik Swietlicki<http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo1800.html#auth-20>, * Alfred Wiedensohler<http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo1800.html#auth-21>, * Douglas R. Worsnop<http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo1800.html#auth-22>, * Veli-Matti Kerminen<http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo1800.html#auth-23> * & Markku Kulmala<http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo1800.html#auth-24> * Affiliations<http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo1800.html#affil-auth> * Contributions<http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo1800.html#contrib-auth> * Corresponding author<http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo1800.html#corres-auth> Nature Geoscience (2013) doi:10.1038/ngeo1800 Received 01 October 2012 Accepted 14 March 2013 Published online 28 April 2013 Atmospheric aerosol particles influence the climate system directly by scattering and absorbing solar radiation, and indirectly by acting as cloud condensation nuclei1<http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo1800.html#ref1>, 2<http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo1800.html#ref2>, 3<http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo1800.html#ref3>, 4<http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo1800.html#ref4>. Apart from black carbon aerosol, aerosols cause a negative radiative forcing at the top of the atmosphere and substantially mitigate the warming caused by greenhouse gases1<http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo1800.html#ref1>. In the future, tightening of controls on anthropogenic aerosol and precursor vapour emissions to achieve higher air quality may weaken this beneficial effect5<http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo1800.html#ref5>, 6<http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo1800.html#ref6>, 7<http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo1800.html#ref7>. Natural aerosols, too, might affect future warming2<http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo1800.html#ref2>, 3<http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo1800.html#ref3>, 8<http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo1800.html#ref8>, 9<http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo1800.html#ref9>. Here we analyse long-term observations of concentrations and compositions of aerosol particles and their biogenic precursor vapours in continental mid- and high-latitude environments. We use measurements of particle number size distribution together with boundary layer heights derived from reanalysis data to show that the boundary layer burden of cloud condensation nuclei increases exponentially with temperature. Our results confirm a negative feedback mechanism between the continental biosphere, aerosols and climate: aerosol cooling effects are strengthened by rising biogenic organic vapour emissions in response to warming, which in turn enhance condensation on particles and their growth to the size of cloud condensation nuclei. This natural growth mechanism produces roughly 50% of particles at the size of cloud condensation nuclei across Europe. We conclude that biosphere–atmosphere interactions are crucial for aerosol climate effects and can significantly influence the effects of anthropogenic aerosol emission controls, both on climate and air quality. -- You received this message because you are subscribed to the Google Groups "geoengineering" group. To unsubscribe from this group and stop receiving emails from it, send an email to geoengineering+unsubscr...@googlegroups.com. To post to this group, send email to geoengineering@googlegroups.com. Visit this group at http://groups.google.com/group/geoengineering?hl=en. For more options, visit https://groups.google.com/groups/opt_out.
