Sharp rise in US road deaths blamed on climate change, not smartphone use
Scientists have blamed an unusual spike in road deaths that struck the United States in 2015 on climate change rather than an increase in the use of mobile phones.
A new study has found that people might have used their vehicles more frequently to avoid increasingly bad weather - rising temperatures and heavier rainfall - resulting in an increased number of deaths on the road.
The finding challenges a widespread notion that 2015’s death hike was the result of increased cell phone usage by motorists.
Road deaths in the United States climbed 7.2 per cent in 2015 over the previous year to 35,200, running counter to a five-decade trend of declining fatalities, according to the US Transportation Department.
Traffic deaths climbed nearly 8 per cent in the first nine months of 2016, government data showed.
Combining government data for the 100 most densely-populated US counties for miles driven, vehicle fatalities and weather, researcher Leon Robertson found that motorists clock up extra miles as temperatures and precipitation rates rose.
When temperature rose by just 0.5 Celsius, vehicles were driven an additional 95km per person over a year, Robertson said, in a study published in the academic journal Injury Prevention.
Using mathematical models, the retired Yale University epidemiologist also found that for every additional 2.5cm of rainfall, cars and trucks racked up an average of 105km per motorist for a year.
Hotter than normal outdoors temperatures likely accounted for most of the extra deaths in 2015, Robertson said.
“If millions more people drive cars because the temperature is getting warmer... then that adds up to a lot of miles,” he said. “Mainly, it’s a simple multiplication.”
In all, motorists in areas he studied may have racked up as many as 13.6 billion more miles of travel, Roberston estimated.
He dismissed the idea that increased cell phones behind the wheel was to blame for the 2015 hike, a theory favoured by some safety officials.
Using a cell phone while driving has been associated with an increased risks of car crashes, but a national survey of observed cell phone use by drivers cited in the study found no change between 2014 and 2015.
In a statement, Roberston said the trend could continue as climate change intensifies.
“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 said in a statement.
The UN Intergovernmental Panel on Climate Change, which includes more than 1,300 scientists, forecasts a global temperature rise of as much as 5 Celsius by 2100, short of significant greenhouse gas emissions cuts.
Pope Francis and Orthodox Christian leader Patriarch Bartholomew have called for a collective response from world leaders to climate change, saying the planet was deteriorating and vulnerable people were the first to be affected.
“We urgently appeal to those in positions of social and economic, as well as political and cultural, responsibility to hear the cry of the earth and to attend to the needs of the marginalised,” they said in a joint statement.