Childhood Diarrhea: What's Diurnal Temperature Range Got to Do with It?
Xu, Z., Huang, C., Turner, L.R., Su, H., Qiao, Z. and Tong, S. 2013. Is diurnal temperature range a risk factor for childhood diarrhea? PLoS One 8: e64713.
In discussing their findings the six scientists say "there was a statistically significant relationship between diurnal temperature range and childhood diarrhea," such that "a 1°C increase in diurnal temperature range was associated with a 3% increase of Emergency Department Admissions for childhood diarrhea."
Xu et al. conclude that "as climate change continues, DTRs are likely to become more variable," and as a result, they say that "the incidence of childhood diarrhea may increase." However, this is likely not the case; for Karl et al. (1984, 1991) have shown that over the course of the bulk of 20th century global warming, daily minimum temperatures rose at a rate fully three times greater than daily maximum temperature over most of the world. And this observation means that DTRs have actually declined over this period, and must have led to significant decreases in emergency department admissions for diarrhea among children under five years of age, which is actually something for which we could thank global warming.
Karl, T.R., Jones, P.D., Knight, R.W., Kukla, G., Plummer, N., Razuvayev, V., Gallo, K.P., Lindseay, J., Charlson, R.J. and Peterson, T.C. 1984. A new perspective on recent global warming: asymmetric trends of daily maximum and minimum temperature. Bulletin of the American Meteorological Society 74: 1007-1023.
Karl, T.R., Kukla, G., Razuvayev, V.N., Changery, M.J., Quayle, R.G., Heim Jr., R.R., Easterling, D.R. and Fu, C.B. 1991. Global warming: evidence for asymmetric diurnal temperature change. Geophysical Research Letters 18: 2253-2256.