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Scientists flew a plane into high up cirrus clouds and used a sampler that resembled a hair dryer to examine cloud formation © Karl FroydMineral dust that swirls up into the atmosphere from Earth’s surface plays a far more important role in both cloud formation and cloud chemistry than was previously realised. The findings will feed into models of cloud formation and chemistry to help produce more accurate assessments of the role of clouds in climate change.Relatively little is understood about the formation of cirrus clouds, wispy ‘horsetails’ that are made of ice crystals and form at extremely high altitudes...

Scientists have found further evidence for the existence of an elusive intermediate implicated in chemical reactions that degrade atmospheric pollutants. A new method of directly detecting the simplest form of this intermediate, as well as more measurements of the intermediate’s reactivity, provide indications that atmospheric models need to improve how they account for them.More than 50 years ago, German chemist Rudolf Criegee proposed that alkenes in the atmosphere, released either by plants or human activities, degrade by reacting with ozone to form a cyclic ozonide. One of the products formed when this ozonide falls apart is a carbonyl oxide called...

Scientists have shown that a newly discovered molecule in Earth's atmosphere has the potential to play a significant role in off-setting global warming by cooling the planet. In a breakthrough paper published in Science, researchers from The University of Manchester, The University of Bristol and Sandia National Laboratories report the potentially revolutionary effects of Criegee biradicals. These invisible chemical intermediates are powerful oxidisers of pollutants such as nitrogen dioxide and sulfur dioxide, produced by combustion, and can naturally clean up the atmosphere. Although these chemical intermediates were hypothesised in the 1950s, it is only now that they have been detected....

Aerosols' complicated influence on our climate just got more threatening: they could make methane a more potent greenhouse gas than previously realized, say climate modellers.Drew Shindell, at NASA Goddard Institute for Space Studies, New York, and colleagues ran a range of computerized models to show that methane's global warming potential is greater when combined with aerosols — atmospheric particles such as dust, sea salt, sulphates and black carbon. The International Panel on Climate Change (IPCC) and treaties such as the Kyoto Protocol assume methane to be, tonne-for-tonne, 25 times more potent than carbon dioxide at warming the planet. But the...