8% of global greenhouse gas emissions are due to tourism, according to a study taking into account transport, food, accommodation and purchases of travelers.

In 2017, international tourism grew by 7%, "the best result ever achieved in seven years" , welcomed at the beginning of the year the World Tourism Organization , which forecast for 2018 a further increase of 4% in 5%. But the UN institution said nothing about the reverse side of these massive movements: their environmental impact, starting with their contribution to global warming.
However, a study of Australian, Chinese and Indonesian researchers, published Monday, May 7 in the journal Nature Climate Change , reveals that the "carbon footprint" of global tourism is considerable. According to their calculations, this activity is responsible for about 8% of humanity's total greenhouse gas emissions. A percentage three times higher than previous estimates, which ranged from 2.5% to 3%. A way of comparison, shipping represents 3% of the global emissions of CO 2 .

To achieve this result, Manfred Lenzen (University of Sidney, Australia) and his colleagues compiled data on tourist flows between one hundred and sixty countries during the period 2009-2013. The originality of their approach is to have accounted for not only the emissions directly associated with transport (such as the combustion of kerosene from aircraft and gasoline or diesel fuel from cars), but also those related to the goods and services consumed by travelers, whether catering, hotels or various purchases.

By adding all these posts, the researchers estimate that global emissions attributable to the tourism sector increased from 3.9 billion tonnes of CO 2 equivalent in 2009 to 4.5 billion tonnes in 2013. It should be noted that these figures include business travel, which is not distinguished from others in this study.

Reward for economic benefits
More than international travel, it is the journeys and the domestic stays which are the source of most of the carbon emissions. Unsurprisingly, Americans weigh the most heavily in this balance sheet, since they are responsible for about a quarter of "tourism emissions". They are followed by Chinese, whose emerging classes are becoming more and more travelers. Then, in the top 10 of the sending countries, Germany, India, Mexico, Brazil, Canada, Japan, Russia and the United Kingdom.

The authors draw attention to the situation of island states, such as the Maldives, the Seychelles, the Republic of Mauritius or the Republic of Cyprus, which are exotic destinations popular with holidaymakers and where mass tourism generates 30% 80% of national CO 2 emissions . A highly paid counterpart to the economic benefits of the influx of visitors.

So far, researchers say, efforts to reduce the carbon footprint of the tourism sector have not been enough to reverse the curve. Air transport is in the front line. Certainly, in October 2016, the 92 member countries of the International Civil Aviation Organization committed to cap emissions from this activity - not covered by the Paris Climate Agreement - to their 2020, until 2035. But in the medium term, the continued growth of global tourism, driven by the rising standard of living of emerging countries, suggests a worsening of its environmental impact.

"We predict that tourism will be a growing part of greenhouse gas emissions," the authors warn. To encourage expatriates to travel less, or less, the only solution may be, they suggest, putting in place a carbon tax that increases the cost of travel. What cool tourists, not to warm the climate further.