Do global travelers have to leave their environmental ethics at home?

What if the best way to save the planet were simply to stay put?

A study published Monday in Nature Climate Change finds that global tourism is responsible for some 8 percent of total carbon emissions – about three times more than what previous studies had calculated.

In 2013, tourism accounted for 4.5 gigatons of carbon emissions. And the industry is growing by about 4 percent a year.

That carbon footprint raises questions of its own: Who bears the responsibility for it? Individuals? Airlines? Travel companies? Policymakers? And what about the benefits of travel? Do the dollars going into economies that rely on tourism, and the increased global understanding travel can foster, help mitigate tourism’s damage?

“There’s a running