It Kills Dinosaurs, Changes Climate, and Eventually Drowns Us

Dust is all-pervasive in our lives. It permeates our atmosphere and even fills the void between stars. In The Secret Life of Dust, Hannah Holmes has breathed life into this dusty topic, with a narrative by turns terrifying and fascinating.

Holmes' dust is not the motes you see floating in a beam of sunlight, but invisibly tiny flecks of dead and once-living stuff. The author wraps the dusty path of everything in these well-written essays: Build stars from it. Water earth and entomb dinosaurs with it. Start and end ice ages in its flight. Share it worldwide. Kill each other and ourselves with it. Nourish tiny grazers and predators—and the Amazon Basin, and the entire world of grain eaters—on it. Smoke it, eat it, drink it, breathe it, and wear a thin sheath of it all our lives. Return to it at life's end.

It is fitting that this tale of dust begins with the birth of the universe, our sun and the Earth; and ends with death, our own transition to dust, and that of our solar system and of the universe. Holmes makes a good case for the triumph of dust.

She also accuses it of all sorts of villainy. Dust is implicated in the creation of a field of amazing dinosaur fossils in China's Gobi Desert. The best theory is that all these animals were overtaken in the midst of their everyday activities by a massive dry mud-slide as a dune of dusty loess soil suddenly collapsed over them.

Dust is also the root cause of plenty of human misery, from black lung and mesothelioma to asthma and heart disease. Airborne dust has been lofting off the Earth's surface long before there were animals, including humans, around to breathe it in. In fact, humans have evolved to be highly efficient at ridding our bodies of most kinds of dust particles. Eventually, however, the "mucus elevator" fails, and we drown in the dust we've inhaled.

From the personal fight against dust, to the global, Holmes points out that increased clouds of dust may have resulted from the cool air and entrapped water of the Ice Ages, and that dust may then have brought about the death of the glaciers. 

Iron-rich dust promotes blooms of carbon-dioxide-spewing phytoplankton (warming), and dust is required to create reflective cloud masses (cooling). She quotes Columbia University's Pierre Biscayne, who works to identify the ancient sources of dust trapped in ice cores from Greenland and Antartica:

"Climate modelers know dust is important, but it's the least well-known parameter in the Earth's thermal balance. Right now, they don't even know its sign."  [Emphasis in original]

This is not a book for the squeamish. If you have not been able to eat sausage since the time you read Upton Sinclair's The Jungle, you may now find the idea of taking deep breaths of sea or woodland air horrifying. Reading this may kindle a desire to remove the carpets, toss your candles in the trash, and convert your fireplace into a cold, clean bed for your pets. You might even hesitate before taking a book down from a dusty shelf.

I recommend reading this excellent book on the Kindle, where it can gather no dust.