A mass die-off of numerous species is currently underway, which could have serious economic consequences for humanity. The situation is especially bad in the North and South Pole. Entire ecosystems all over the world are under threat. The surface temperature of our seas has been rising steadily since 1970. One consequence of that is thermal expansion, leading to a rise in sea levels. Around countries like Norway that rise is two to three times as fast due to the additional melting of the polar ice caps. A number of commercially important fish species have begun migrating to cooler waters, as their traditional territories have become too warm for them. It is a trend that’s affecting regions around the world. Many developing countries that depend on fish as a key source of food stand to be especially hard hit. We accompany marine biologist Lukas Müller on an expedition to Norway. He travels the world conducting research into how our seas can be better protected. In Norway, he goes freediving in the Arctic Ocean where he encounters orcas and humpback whales in water temperatures around freezing. Orcas are found in a wide range of marine environments and are not directly affected by climate change. But through the complex, interwoven food chain in our oceans, climate change does pose a threat to these huge marine predators. The world’s seas are essential to human existence. Not least, because they serve as huge carbon sinks that help regulate our climate. But the climate crisis is now changing the entire marine ecosystem. The question is whether we humans can live with the consequences.