"Keeping everything in balance is one of the functions of the blue machine, but the... gradual raising of world temperatures poses a significant threat... It is only at the very end of her book that Czerski directly addresses the environmental changes... Her concern up to that point has been to set out clearly and calmly the design of the ocean engine. But... her... closing chapter on ‘the future’... is clear... the blue machine is... resilient, but will suffer permanent damage from rising temperatures. ...sea levels; currents... diverted; the fishy inhabitants... disperse and... disappear; tropical storms.. increase in frequency and power; sub-surface areas... de-oxygenated—all... alongside... the ocean as... dumping ground for plastic and... detritus. The oceans absorb carbon... breathe out carbon dioxide... determine global temperatures, but there are limits to their capacity..."