Is Climate Change the World’s Most Important Problem?

A 2005 review article in Nature on the health impacts of climate change provided an estimate of 166,000 deaths as the annual global death toll “attributable” to climate change. This estimate, based on global vital statistics for the year 2000, was derived from a study sponsored by the World Health Organization (WHO) that even the study’s authors acknowledge may not “accord with the canons of empirical science” (see here). Let’s, nevertheless, accept this flawed estimate as gospel, for the sake of argument.

Where would this rank climate change in the list of global threats to mortality?

In the year 2000, there were a total of 55.8 million deaths worldwide. Thus, climate change may be responsible for less than 0.3% of all deaths globally (based on data for the year 2000). In fact, it would place climate change no higher than 13th among mortality risk factors related to food, nutrition and environment, as shown in the following table taken from pages 355-356 of the book, The Improving State of the World.

[Notably, all extreme weather events (whether due to climate change or the normally abnormal climatic variability) contribute all of 0.03% of global deaths on average. See Table 2, here.]

Specifically, climate change is easily outranked by threats such as hunger, malnutrition and other nutrition-related problems, lack of access to safe water and sanitation, indoor air pollution, malaria, urban air pollution.

With respect biodiversity and ecosystems, today the greatest threat is what it always has been -- the conversion of land and water habitat to human uses, i.e., agriculture, forestry, and human habitation and infrastructure. See,e.g., here.

Climate change, contrary to claims, is clearly not the most important environmental, let alone public health, problem facing the world today.

But is it possible that in the foreseeable future, the impact of climate change on public health could outweigh that of other factors?

I’ll get to this question in subsequent blogs over the next couple of weeks, but for those who can’t wait, the answer can be found here.