Arizona is likely to face significant consequences to climate change

The dangers of climate change revealed in Death by Degrees: The Health Threats of climate change in Arizona, published by Washington-based Physicians for Social Responsibility, include changes in the quality and supply of water, increased accidents and injuries, and an increased risk of infectious diseases. The report is the latest in a series by the organisation, which has already included health effects in states such as Florida, New Hampshire, Ohio and North Carolina.

Climatic changes that are predicted for the region include a 7°F increase in the winter, and a summertime rise of 9°F, says the report. Rainfall patterns are projected to change, although specific changes are still not completely predictable. Many experts expect winter precipitation to increase, with more falling as rain due to the higher temperatures, and summer rainfall to be reduced. Earlier snowmelt could also result in worsening spring floods and loss of stored water in the form of snow for later use.

The state already has a wide variety of climatic conditions, from desert which has less than five inches (13cm) of rainfall a year, to mountains rising well above 12,000 feet (3700 metres) which receive more than 20 inches (51cm) of rain per year. Temperatures at the same location can even vary by as much as 50°F in a 24 hour period. However, the changes projected over the next 100 years could prove to be the greatest challenge yet, says the report’s author Cindy Parker MD.

Increased evaporation and a reduction in rainfall could require more crop irrigation, further jeopardising water resources, although, conversely, there could be flooding in some areas, with both drought and floods impairing water quality. Contamination of drinking and recreational water by animal and human wastes is more apt to occur after heavy rainfall, leading to bacterial, parasitic and viral infections, says the report. It is also possible that there will be an increase in fungal disease, such as valley fever, food-borne disease, rodent-carried diseases, such as hantavirus and plague, as well as diseases carried by mosquitoes. A decrease in air quality, such as from an increase in smog, and smoke from forest fires sparked by drought, would cause more frequent and severe attacks of asthma and a worsening of other respiratory and cardiac problems. Heat related illness could also increase significantly, with vulnerable groups such as the elderly at particular risk.

Climate change may also affect food supply, through decreased yields of wheat and cotton, and a reduction in ranching yields. Finally, accidents and injuries could rise as a result of climate change, such as through an increase in flooding and flash floods, and an increase in airborne dust and sand storms which could affect highway and airport safety.

As with elsewhere in the world, there is considerable uncertainty in predictions in climate change and its effects, which means that it is difficult for the people of Arizona to make adequate preparations for specific outcomes, the report points out.