Climate change may be linked to spike in US road deaths in 2015

August 31, 2017, British Medical Journal

Climate change may be linked to the spike in US road deaths in 2015, which abruptly reversed the trend of the previous 35 years, concludes a study published online in the journal Injury Prevention.

Safety officials had thought that increased use of cell phones while behind the wheel had been responsible for the 7 per cent surge in road traffic collision deaths in 2015.

But a national survey of observed cell phone use by drivers found no change in use between 2014 and 2015, which also happened to be an exceptionally warm year in the US.

This prompted the researcher to ponder whether warming of the atmosphere might be behind the figures.

He therefore looked at two sets of data to assess the potential association between and rainfall on the annual miles driven per person in urban areas and risk of per head in the 100 most densely populated counties in the US.

The average annual temperature increased 1.5 degrees Fahrenheit from 2014 to 2015 in the areas studied.

Vehicles were driven an average of 60 extra miles per year per person for each degree increase in temperature, and they were driven an average of 66 additional miles for each additional inch of rainfall.

The death rate was higher in warmer areas and in those with higher rainfall. It was also higher in counties with larger land mass and where the speed limit on urban freeways was higher.

Conversely, the death rate was lower in households with higher average income, possibly because drivers are able to afford more up to date models equipped with more safety features, suggests the researcher.

Based on the association between miles driven per person and average annual temperature in , drivers would have clocked up 13.6 billion extra miles as the result of a 1.5 degree increase, calculates the researcher.

Death rates increase steadily as temperatures rise, not only because more people drive on warmer days, but other road users are more likely to be out about on foot or on bikes as well, he says.

Comparison of the number of deaths that would be expected from the temperature changes and the actual numbers suggests that most of the reversal in the death rate in 2015 was related to increases in temperature in the counties where this occurred.

Although the increase in temperature from 2014 to 2015 was unusual for a single year, it is consistent with known effects of heat trapping gases from burning fossil fuels, says the researcher.

This is an observational study so no firm conclusions can be drawn about cause and effect, but the correlation of mileage and temperature suggests a classic vicious circle whereby higher temperatures equal more miles driven, leading to more CO2 emissions, which in turn lead to higher temperatures," he explains.

"As temperatures continue to increase from heat-trapping gases in the atmosphere, road deaths will likely increase more than expected unless there are major mitigating countermeasures," he concludes.

Explore further: Outdoor air temperature linked to risk of gestational diabetes

More information: Climate change, weather and road deaths, Injury Prevention (2017). ip.bmj.com/lookup/doi/10.1136/ … juryprev-2017-042419

Related Stories

Outdoor air temperature linked to risk of gestational diabetes

May 15, 2017
Outdoor air temperature has a direct link to the risk of gestational diabetes, with a 6% to 9% relative increase in the risk of diabetes for every 10°C increase in temperature, according to a study published in CMAJ (Canadian ...

Recommended for you

Removing sweets from checkouts linked to dramatic fall in unhealthy snack purchases

December 18, 2018
Policies aimed at removing sweets and crisps from checkouts could lead to a dramatic reduction to the amount of unhealthy food purchased to eat 'on the go' and a significant reduction in that purchased to take home, suggests ...

Junk food diet raises depression risk, researchers find

December 18, 2018
A diet of fast food, cakes and processed meat increases your risk of depression, according to researchers at Manchester Metropolitan University.

Children of problem drinkers more likely to marry someone with a drinking problem: study

December 18, 2018
Children of parents who have alcohol use disorder are more likely to get married under the age of 25, less likely to get married later in life, and more likely to marry a person who has alcohol use disorder themselves, according ...

Folate deficiency creates hitherto unknown problems in connection with cell division

December 17, 2018
Folate deficiency creates more problems in connection with DNA replication than researchers had hitherto assumed, researchers from the University of Copenhagen show in a new study. Once a person lacks folate, the damage caused ...

A co-worker's rudeness can affect your sleep—and your partner's, study finds

December 14, 2018
Rudeness. Sarcastic comments. Demeaning language. Interrupting or talking over someone in a meeting. Workplace incivilities such as these are becoming increasingly common, and a new study from Portland State University and ...

Study shows magnesium optimizes vitamin D status

December 14, 2018
A randomized trial by Vanderbilt-Ingram Cancer Center researchers indicates that magnesium optimizes vitamin D status, raising it in people with deficient levels and lowering it in people with high levels.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.