Environmental campaigners are warning the tranquillity of the South West countryside could be ruined if airports expand.
Exeter Airport has seen thousands of more passengers over five years
In the past decade, air travel in the South West has risen faster than any other English region, according to the Department for Transport.
The Council for the Protection of Rural England (CPRE) has said there should be more investment in high-speed rail alternatives.
But business leaders say a balance must be struck between the needs of the environment and the local economy, and airports must expand if the region is not to become marginalised.
Exeter Airport alone has seen an increase in passenger numbers from 250,000 in 1998 to 336,500 in 2002.
The government is determined to look at a 30-year strategy for air transport, why are we not looking at a 30-year strategy for rail?
The airport says it believes it could reach its maximum capacity by 2008.
The Council for the Protection of Rural England (CPRE) is concerned at the impact this could have on the environment.
It says the peace and tranquillity of protected areas like Dartmoor would be ruined by more air traffic.
CPRE aviation campaigner Andrew Critchell said: "The Royal Commission on Environment Pollution has said the most damaging flights with regards to greenhouse gas emissions are short-haul domestic flights.
"This exactly where there is a huge opportunity to augment this with high-speed rail.
"If the government is determined to look at a 30-year strategy for air transport, why are we not looking at a 30-year strategy for rail?"
But Tim Jones from the Devon and Cornwall Business Council said the CPRE is being narrow-minded.
The government is keen airports should meet as much local demand as they can
He said: "I'm disappointed in this.
"There has to be an understanding that commercial development has to take place."
The Department for Transport said: "In South West England, demand for air travel is growing fast and the government is keen airports should meet as much local demand as they can.
"But because air links between the South West and London are limited, we are looking both at developing these further and at improved rail connections to London airports".