Speaking at a meeting at the University of Leicester in England, Vladimir Shaidurov of the Russian Academy of Sciences said that the planet is, indeed, warming, but that this is nothing to do with human activity.
The warming is caused by reduced air moisture at high altitudes, where clouds formed of minute ice crystals stop some of the sun’s rays from reaching the earth’s surface, he explained.
The abundance of water vapour, the most potent natural greenhouse gas, is not affected by human activities. But a large-scale natural event, such as a comet or asteroid impact, could affect water vapour concentrations at high altitudes, Shaidurov claims.
A comet that crashed into the earth’s atmosphere over a remote region of Eastern Siberia, north-west of Lake Baikal, in 1908 qualifies as such an event, said the scientist. The impact could have destroyed enough ice crystal clouds for prolonged warming to take hold, according to Shaidurov’s theory.
The comet, known as the Tungusk Meteorite, released an energy equivalent to fifteen atomic bombs and felled trees across 2000 square km of the taiga when it exploded on impact with the atmosphere. The event caused “considerable stirring of the high layers of atmosphere and changed its structure,” Shaidurov said.
Analysing global temperature data over the last 140 years, the scientist found that the 20th century temperature rise begins between 1906 and 1909, corresponding perfectly with the impact of the Tungusk Meteorite.
The results are being considered for publication in the journal Science First Hand.
By Goska Romanowicz