How green is my EV? It’s a lot like one of those maths problems
that gave you fits in sixth grade: A salesman leaves home in
Denver and drives his electric car to a meeting in Boulder. At
the same time, a physicist driving the same model electric car
sets out from her loft in Los Angeles, heading to an appointment
near Anaheim. For both, the traffic is light, and the cars
consume an identical amount of battery power while travelling
the same number of kilometres. Being purely electric, they emit
zero tailpipe pollutants during their trips. The test question:
Are their carbon footprints also equal? The answer may be a
surprise. According to a report that the Union of Concerned
Scientists plans to release this week, there would be a
considerable difference in the amount of greenhouse gases -
primarily carbon dioxide - that result from charging the cars’
battery packs. By trapping heat, greenhouse gases contribute to
climate change. The advocacy group’s report, titled ‘‘State of
Charge: Electric Vehicles’ Global