In Bill Bryson's "A Short History of Nearly Everything," he discusses the delicate balance of the Earth's oceanic systems and how even minor changes can have significant consequences. Bryson highlights that a small reduction in the salt concentration of the oceans, such as from the melting Greenland ice sheet, could disrupt oceanic circulation patterns and impact climate drastically. This underscores the interconnected nature of Earth's systems and the potential risks posed by climate change.

The book serves to inform readers about the intricate relationships in our environment and the fragile state of our planet. Bryson emphasizes that understanding these dynamics is crucial, as they influence not only marine life but also global weather patterns and ecosystems. The potential for disastrous effects from seemingly minor changes illustrates the importance of addressing climate issues effectively.