Report raises fears over space tourists' climate impact

Environmentalists have already raised concerns about the carbon footprint of proposed space tourism flights, such as that planned by British billionaire Richard Branson, but according to new research the controversial flights could have an even more immediate impact on the world's climate.

A new study, accepted for publication in Geophysical Research Letters, predicts that soot emitted by rockets in the upper atmosphere would lead to significant disruption to the world's climatic system resulting in a net increase in temperatures.
The report, which was funded by NASA and The Aerospace Corporation, assumes that the nascent space tourism industry makes good on plans to carry out up to 1,000 suborbital rocket flights a years by the end of the decade.

The resulting computer models predict that the resulting stratospheric layer of rocket soot would remain relatively localised in latitude and altitude, meaning that the earth's surface could cool by as much as 0.7 degrees Celsius in some areas, while other areas would warm with Antarctica expected to see temperatures rise by up to 0.8 degrees Celsius.

The report also warned that the Ozone layer would be affected with equatorial regions losing about one per cent of ozone cover and poles gaining about 10 per cent.

It concluded that "the globally integrated effect of these changes is, as for carbon dioxide, to increase the amount of solar energy absorbed by the earth’s atmosphere".

Martin Ross, the study's chief author who works for The Aerospace Corporation in El Segundo, California, urged the emerging industry to step up efforts to understand the environmental impacts of suborbital flights.

"Rockets are the only direct source of human-produced compounds above about 14 miles [22.5 kilometers] and so it is important to understand how their exhaust affects the atmosphere," he said in a statement. "Climate impact assessments of suborbital and orbital rockets must consider black carbon emissions, or else they ignore the most significant part of the total climate impact from rockets. This includes existing assessments that may need to be brought up to date."

The research comes just days after Branson opened the runway at the world's first commercial spaceport in Mexico and announced that he expected the first commercial space flights operated by his Virgin Galactic firm to begin within the next nine to 18 months.