New Book Explores Affects of Climate Change on Human Health

A new book, Climate Change and the Health of Nations: Famines, Fevers, and the Fate of Populations, by public health expert Anthony McMichael and epidemiologist Alistair Woodward, sheds light on how sensitive humans may be to climate change by looking at how climate has changed over time in the past and how those changes impacted human health.

For example, climate impacts from the 1815 the eruption of Mount Tambora, a 13,000 ft. tall volcano on one of Indonesia’s islands, was felt globally around the world. In addition to causing an estimated 10,000 people to die instantly, the volcano spewed so much ash into the atmosphere that it caused average global temperatures to fall by 2-3 ° C and was responsible for the unseasonable chill that afflicted much of the Northern Hemisphere in 1816, which is known as the “year without a summer.”

The temperature decline caused a decade of crop failures from frost and/or lack of sunshine and famine. Nutritional deficits in people triggered epidemics and infectious diseases. In addition, mass migrations and social unrest occurred as people moved from one place to another to find more secure food supplies. Impact of the sudden change in climate can be seen in population numbers, fertility, and infectious disease rates.

The difference between climate change and the past eruption of Mount Tambora is that while ash in the atmosphere after Mount Tambora settled out within 2-3 years, carbon dioxide will remain in the atmosphere for a long time and is putting a momentum into climate change that wasn’t present in the past.

The authors explain that humans and other life forms thrive within a particular climate range, a so Goldilocks Zone in which climatic conditions are just right. Human physiology requires that we keep our bodies at a particular temperature and if the external environment changes too much from what we’re used to it stresses the body. In addition, disease vectors such as the mosquito, responds quite rapidly to increases in temperature, which boost its activity, feeding patterns, and reproduction. In the 1400s warmer temperatures in Central Asia made animals like marmots and rats more active, and that, combined with increased trade and movement of people out of the middle east into the Mediterranean (which was also climate induced) contributed to the spread of the bubonic plague in Europe.

The big problem we as people have in trying to mobilize effectively to stem the effects of climate change is that humans have evolved to pick up immediate, visible threats. The negative effects of climate change are so big picture that it’s hard to grasp them. The authors of this book examine the evidence of climate and crises—epidemics, bush fires, storms—because these are things humans can more easily understand.

For more information see: Past Disasters Reveal Terrifying Future of Climate Change.  See more about the book.