Note the predicted trend (straight red line) compared with some actual observations.
Algae and plankton are at the bottom of the food chain. Plankton includes many different kinds of tiny animals, plants, or bacteria that just float and drift in the ocean. Other tiny animals such as krill (sort of like little shrimp) eat the plankton. Fish and even whales and seals feed on the krill. In some parts of the ocean, krill populations have dropped by over 80 percent. Why? Krill like to breed in really cold water near sea ice. What would happen if there were no sea ice? What would happen if there were very little plankton or krill? The whole food web could come unraveled.'
Quote 'The whole food web could come unraveled.'
Do you think by any chance they want to scare the 'kids'?
Q. How can they justify this?
A. Because the model projections look alarming
Might be enough to persuade you to read Bob Tisdale's article linked to above.
Or research into what kind of of temperature rise would mean 'the ocean gets too warm'.