Global tourism is expected to plunge by 70% this year, compared to last year, the head of the United Nations World Tourism Organization (UNWTO) said Wednesday.

Previous global crisis situations have caused tourism to decline by 10% to 20%, but the Covid-19 pandemic has been worse, said UNWTO Secretary General Zurab Pololikashvili, in a video press conference with reporters in Madrid.

This summer, more people will take trips by land, rather than on flights, and rural tourism in the mountains, and not on the beaches, may benefit, he said.

The UNWTO expects more international flights to resume starting in September if the virus is more under control by then, he said.

Some more details: In a statement on May 11, the Madrid-based UNWTO said its research through late April found that 100% of the 217 destinations they tracked worldwide had coronavirus-related travel restrictions for international tourists.

As countries begin to reopen for travel, Pololikashvili said Europe will be seen as a model to follow, because it is historically the most visited region, and the best prepared, including its health care infrastructure.

So called “green corridors” which would permit targeted travel between two regions, in different countries, that have demonstrated low infection rates of Covid-19, could be a first step to restarting international tourism, he said.

But Pololikashvili said he prefers to call them “safe corridors,” so that tourists won’t take the virus to their destination and also won’t bring it back home.