A plan to build a new 14-gate concourse at Mineta San Jose International Airport in California has been unveiled by local officials but still must clear environmental review, the San Jose Mercury News reports

The expansion plan, which also includes a 330-room hotel and a 5,000-vehicle parking facility, would result in “significant and unavoidable” amounts of greenhouse gases as capacity at the airport rises by 50 per cent by 2037, according to a draft environmental review report.

Now, local officials will need to weigh whether the trade off between pollution and capacity is acceptable.

“If you didn’t take the increase of air traffic into effect, the other work [like increased ground traffic] could be offset with sustainability measures,” said Greg Nudd, deputy air pollution officer for policy at the Bay Area Clean Quality Management District.

“A lot of people don’t realise how carbon-intensive flying is.”

Airport officials argued that if the San Jose airport isn’t expanded to meet demand, travellers will simply drive further to get to other regional airports that have the flights they want.

“The need for air travel and the demand for air travel in San Jose is going to grow regardless of whether we build anything new or not,” said Scott Wintner, deputy director of marketing and communications at the airport.

“But these projects will make the airport more efficient, so that planes are spending less time idling and waiting for a gate to open, which would only generate more emissions.”