Transportation fuels with zero carbon could turn into sources of pollution

Switching from burning fossil fuels to burning ammonia is a promising way for the shipping industry to reduce its carbon footprint. However, if you are not careful, this exchange can also promote harmful nitrogen pollution.

“That's a huge alarm bell,” he says. Shin Chan at the University of Maryland.

The tens of thousands of ships at sea account for about 3 percent of global CO2 emissions, with more than 300 ships burning.