Richard has it absolutely right.  The obvious answer is to seek fewer but higher-spending tourists.  I have just returned from visiting my hometown, Palma de Mallorca, the O‘ahu of the Mediterranean.  The trend there is clear: the vast majority of new hotels are small “boutiques” some of which charge as much as $900 a night.  A tourist who has that kind of money to spend just on a place to sleep has the moolah to plonk down on high-end restaurants, pricey spa services and other expensive activities that would pump more money per person into our economy than the mass-market tourism we typically pursue.  The dissonance between the ultra-rich tourists and the low-income service workers who wait on them is jarring, but worker income for those working in 5 star establishments is typically higher, while relying on a smaller number of tourists to fuel the visitor industry will result in a smaller environmental footprint.