A study on the environmental impacts of space tourism suggests that a surge in private access to space could speed global warming. Led by Martin Ross, an atmospheric scientist at the Aerospace Corporation in El Segundo, California, it shows that sooty emissions from 1,000 rocket launches per year would add as much to climate change as current emissions from the global aviation industry. It has been accepted for publication by Geophysical Research Letters.

Perhaps the most striking aspect of the study is not the projected impact on polar temperature and sea ice, but the size of the industry it models. Three launches a day? Don't bet against it. Barely a decade after US multimillionaire Dennis Tito paid around US$20 million for a trip to the International Space Station (ISS), space tourism, at least the suborbital type, seems poised for serious lift-off.

The private spaceflight industry is making steady progress. Space-port America, a launch site in Las Cruces, New Mexico, opened its first runway last week. Earlier this month, US President Barack Obama signed into law the NASA Authorization Act, which, subject to approval by Congress, will see the agency hand over $15 million a year to help commercial suborbital efforts.

NASA is keen because it sees what many space scientists have been slow to realize: such suborbital flights could carry research payloads. Virgin Galactic, a pioneer of space tourism, has already indicated that it would be happy to host scientific experiments on its SpaceShipTwo vehicle. A number of fields including atmospheric, space and microgravity research could benefit. A closer relationship with scientists could help the industry in return, through work to quantify and reduce its environmental impact, for instance.

A strong advocate of closer ties between rocketeers and researchers is Alan Stern, a planetary scientist at the Southwest Research Institute in San Antonio, Texas, and a former NASA associate administrator, who chairs the Suborbital Applications Researchers Group of the Commercial Spaceflight Federation in Washington DC. Stern says that private suborbital vehicles will be a game-changer for science, because of low costs and the high number of flights. Earlier this year, his group organized the first conference to promote the benefits of private space flights to scientists. A second event is scheduled for February 2011 at the University of Central Florida in Orlando.

Space scientists who wish to fly experiments currently face high costs and long waits for room on the ISS or sounding rockets, or frustratingly brief periods of microgravity in drop-tubes or parabolic aircraft (known with little affection by those who have been aboard as 'vomit comets'). Suborbital flights could offer several minutes of weightlessness for a fraction of the cost of a conventional launch. And the experiments could be supervised by scientists able to fly alongside their kit. An early winner could be the search for vulcanoids — asteroids that orbit the Sun closer than Mercury. None has yet been discovered, perhaps because observing them from the ground or high-altitude flights is so awkward.

Although NASA has been quick to identify and nurture the potential of space-tourism operators, others have been more sluggish to recognize their potential. The European Space Agency, for example, has an official position on private suborbital flights only of “cautious interest and informed support”. Countries outside the United States have not yet taken the necessary legal steps to open their skies to private operators. Perhaps this reflects scepticism about whether the endeavour will reach the necessary economy of scale, which depends on the number of tourists who sign up. That is a reasonable position at this stage, but space scientists and administrators should drop any snobbish objections they have to the private sector. Those who do not embrace the possibilities could find themselves, quite literally, left behind.