Flood, famine, fire and disease—climate change is expected to have an impact on all of these threats, by altering the earth in many ways, from changes in the planet's water cycle to making a broader swath of the planet amenable to insect-born illnesses such as malaria. A new study in the November issue of Health Affairs by public health scientists (most of whom work for an environmental group, the Natural Resources Defense Council) attempts to put a price on all that change.

These researchers picked six representative disasters and tallied up the economic impact as a first estimate of the kinds of health-related costs climate change might bring. By the group's calculation, the six "climate change-related" disasters—ranging from the Red River floods in North Dakota in 2009 to worsening levels of smog pollution nationwide—accounted for roughly $14 billion in lost lives and healthcare costs.

Using the U.S. Environmental Protection Agency's preferred method [pdf] of assigning a dollar amount to every lost life, the researchers estimated that the 1,689 premature deaths from all six catastrophes cost $7.9 million each—meaning casualties contributed the bulk of the climate change costs. Health care costs from hospitalizations, emergency room visits and consulting doctors, on the other hand, tallied a much more manageable $740 million (which is not chump change, mind you).

Of course, the dollar amount sets aside the human misery and suffering caused by the six catastrophes—which also included the 2003 wildfire and 2006 heat wave in California, Florida's 2004 hurricane season and a West Nile Virus outbreak in Louisiana in 2002—but that's what economists like to do, and what seemingly drives political decision-making.

Although this study represents a first effort to quantify such health-related economic impacts, it ultimately raises more questions than it answers. West Nile's appearance in the U.S. is at least as much due to international travel as any climate change, and the scientific jury is out on whether hurricanes will be made stronger or less frequent (or both) by global warming. Further, the health impacts from the Florida hurricanes had more to do with the carbon monoxide poisoning that followed improper use of generators than a direct impact of hurricane winds or rains, as the report noted.

There are also plenty of other potential climate change impacts that do not factor here, ranging from the waterborne disease outbreaks that follow flooding to infrastructure damage. Nor did the researchers include "lost leisure time, days when activity is restricted, lost school days for children, and lost work and leisure time for those who instead must visit and care for patients," they write. The costs, if any, are likely to fall disproportionately on those least financially capable of dealing with them.

But, even independent of climate change, dealing with smog seems to make health care economic sense based on recent recent research from the EPA and others. More than 287 million Americans live in areas where ground-level ozone levels climb above 80 parts-per-billion for extended periods, according to the Health Affairs research, which has been linked to everything from asthma to increased heart disease. The primary culprits are our cars and our coal-fired power plants.

Reducing the emissions of nitrogen oxides from tailpipes and smokestacks is one sure way to cut down on smog-related death and disease—and yet the Obama administration recently announced plans to avoid mandating such smog reductions until after the 2012 election. The reason? The new rules would cost car manufacturers and electric utilities, among others, some $90 billion. Numbers do matter.

Image: Several massive wildfires were raging across southern California over the weekend of October 25, 2003. Image courtesy Jacques Descloitres, MODIS Rapid Response Team at NASA GSFC.