David Attenborough's Blue Planet II began on Sunday night and became the most watched show of the evening with a whopping 10.3 million viewers. One emotional moment in particular had people in floods of tears.
The scene, which was shot in Svalbard, Norway, showed a walrus and her cub trying to escape starving polar bears.
David Attenborough explained that rising sea temperatures made it harder for the walruses to find safety on an ice float. At one point their fate looked sealed, as the mother cradled its pup in the sea - but thankfully they finally found refuge.
The bittersweet moment provoked a strong reaction from viewers, many of whom confessed to fighting back tears:
Yet others highlighted that it was just one of an increasing number of issues affecting the natural world due to climate change.