Global tourism is responsible for about eight percent of global greenhouse gas emissions -- four times more than previously believed, according to the results of a new study.
The findings, published in the journal , show that the environmental impact of globetrotting travelers -- particularly affluent jetsetters -- has been significantly underestimated.
Unlike other studies which quantify the carbon footprint of travel by looking mostly at air travel and transport, a team of researchers from Australia and Taiwan took a more comprehensive approach by considering the "life cycle" of a tourist, expanding the criteria to food, shopping and accommodations.
After looking at tourism-related activities among 160 countries between 2009 and 2013, researchers estimated that tourism's global carbon footprint increased from 3.9 to 4.5 GtCo2e (gigatonnes of equivalent carbon dioxide) -- or four times more than previous estimates.
Researchers also showed that wealthier travelers -- who are more likely to travel by air and consume more goods and services -- leave behind bigger carbon footprints than lower-income travelers.
Topping the carbon footprint ranking is the U.S., followed by China, Germany, India and Mexico, and mostly from domestic travel.
At the per-capita level, small island destinations like the Maldives, Mauritius, Cyprus and the Seychelles feature some of the highest destination-based footprints, with international tourism representing between 30 and 80 percent of national emissions -- a reality that presents a significant dilemma, authors note.
"In particular, island destinations face an enormous additional carbon burden as they host a significant number of inbound tourists. These islands benefit substantially from the incomes from tourists, so their governments face a challenge of how to impose national mitigation strategies without reducing tourism income," reads an excerpt.
The study also found that Canadian, Swiss, Dutch, Danish and Norwegian travelers leave a bigger carbon footprint in the countries they visit, compared to visitors to their own countries.
With global travel projected to grow four percent beyond 2025, researchers emphasize the need to monitor and mitigate tourism-related carbon emissions, perhaps with carbon taxes or carbon trading schemes.
