Clarksons is not predicting a recession, but it did raise a warning flag Tuesday.

The shipbroking giant said in a report that, if world GDP growth slowed to 2%, capesize bulker rates could fall as low as $12,000 per day and panamax boxships to $8,000, while crippling the anticipated tanker rally brought on by IMO 2020 emissions regulations.

"We still believe in our base case, although we think investors are presently unlikely to subscribe fully to the thesis," read the report, written by analysts Frode Morkedal, Erik Hovi and Henriette Vevstad at Clarksons Platou Securities in Oslo.