WATERLOO, Ont. (Monday, Dec. 21, 2009) - Cosmic rays and chlorofluorocarbons (CFCs), both already implicated in depleting the Earth's ozone layer, are also responsible for changes in the global climate, a University of Waterloo scientist reports in a new peer-reviewed paper.
In his paper, Qing-Bin Lu, a professor of physics and astronomy, shows how CFCs - compounds once widely used as refrigerants - and cosmic rays - energy particles originating in outer space - are mostly to blame for climate change, rather than carbon dioxide (CO2) emissions. His paper, derived from observations of satellite, ground-based and balloon measurements as well as an innovative use of an established mechanism, was published online in the prestigious journal Physics Reports.
"My findings do not agree with the climate models that conventionally thought that greenhouse gases, mainly CO2, are the major culprits for the global warming seen in the late 20th century," Lu said. "Instead, the observed data show that CFCs conspiring with cosmic rays most likely caused both the Antarctic ozone hole and global warming. These findings are totally unexpected and striking, as I was focused on studying the mechanism for the formation of the ozone hole, rather than global warming."
His conclusions are based on observations that from 1950 up to now, the climate in the Arctic and Antarctic atmospheres has been completely controlled by CFCs and cosmic rays, with no CO2 impact.
"Most remarkably, the total amount of CFCs, ozone-depleting molecules that are well-known greenhouse gases, has decreased around 2000," Lu said. "Correspondingly, the global surface temperature has also dropped. In striking contrast, the CO2 level has kept rising since 1850 and now is at its largest growth rate."
In his research, Lu discovers that while there was global warming from 1950 to 2000, there has been global cooling since 2002. The cooling trend will continue for the next 50 years, according to his new research observations.
As well, there is no solid evidence that the global warming from 1950 to 2000 was due to CO2. Instead, Lu notes, it was probably due to CFCs conspiring with cosmic rays. And from 1850 to 1950, the recorded CO2 level increased significantly because of the industrial revolution, while the global temperature kept nearly constant or only rose by about 0.1 C.
In previously published work, Lu demonstrated that an observed cyclic hole in the ozone layer provided proof of a new ozone depletion theory involving cosmic rays, which was developed by Lu and his former co-workers at Rutgers University and the Université de Sherbrooke. In the past, it was generally accepted for more than two decades that the Earth's ozone layer is depleted due to the sun's ultraviolet light-induced destruction of CFCs in the atmosphere.
The depletion theory says cosmic rays, rather than the sun's UV light, play the dominant role in breaking down ozone-depleting molecules and then ozone. In his study, published in Physical Review Letters, Lu analyzed reliable cosmic ray and ozone data in the period of 1980-2007, which cover two full 11-year solar cycles.
In his latest paper, Lu further proves the cosmic-ray-driven ozone depletion theory by showing a large number of data from laboratory and satellite observations. One reviewer wrote: "These are very strong facts and it appears that they have largely been ignored in the past when modelling the Antarctic ozone loss."
New observations of the effects of CFCs and cosmic rays on ozone loss and global warming/cooling could be important to the Earth and humans in the 21st century. "It certainly deserves close attention," Lu wrote in his paper, entitled Cosmic-Ray-Driven Electron-Induced Reactions of Halogenated Molecules Adsorbed on Ice Surfaces: Implications for Atmospheric Ozone Depletion and Global Climate Change.
The paper, published Dec. 3 in Physics Reports, is available online at: dx.doi.org/10.1016/j.physrep.2009.12.002.
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Source: University of Waterloo