The National Trust says the South West's tourism industry could be damaged by plans to expand local airports.
Plans for a new airport are opposed by environmentalists
The Trust's Blue Skies report says the economic value of the region's environment is at least three times higher than its air travel.
It says the benefits of expanding air travel in the region is questionable, as there are 19.6 million domestic visitors, compared with 1.4 million overseas tourists.
However, business groups say airports need to ensure they benefit from being used by local travellers to help the local economy.
The report comes amid uncertainty over the region's air travel.
There can be a far better future for aviation and domestic tourism than spiralling demand and environmental damage
There have been proposals for a new airport in the South Hams, while Plymouth's air links to London are changing, due to the withdrawal of British Airways' services.
The Trust, which has protective ownership of much of the South West's coastline, including some 100 miles of Devon's, is calling on the government to increase taxes on air travel and encourage more people to holiday at home.
It points to short break holidays and extending the season into quieter parts of the year as two priorities that could have a real impact.
It said these moves could be backed by government action to end the range of tax breaks and subsidies for aviation.
The report warns that inbound foreign visits have been falling since 1998 while more and more Britons are holidaying abroad.
Tony Burton, director of policy and strategy for the National Trust, said: "The National Trust believes there can be a far better future for aviation and domestic tourism than spiralling demand and environmental damage.
"Growth forecasts do not have to be taken at face value and we can reduce the pressure for airport expansion by making much more of the opportunities for people to holiday on their doorstep."
However, the South West Regional Development Agency says that two-thirds of South West people who use air travel fly from airports outside the region.
It says this is one of the highest levels of "leakage" in the UK, and the situation is not sustainable.
The agency says more demand must be met from local airport to ensure the region gets more economic benefit from air travel.