Except it isn't true. An electric vehicle creates about 20% less CO2 to produce the same amount of energy than a conventional gas-powered automobile.
A couple references to back me up:
Electric Cars and CO2 Emissions
Council hears about electric car impacts on power system
"Kinter-Meyer told the Council that Battelle’s research suggests that between 43 and 73 percent of all the cars and light trucks in the nation today could be replaced by plug-in hybrid electric vehicles without adding new power plants or transmission lines, depending on the time of day that the vehicles would be charged.
If this were to happen, America’s net oil imports would be reduced by 52 percent, the nation’s total emissions of carbon dioxide would be reduced by 27 percent, and the batteries in all of those vehicles would provide an important source of storage capacity that could enhance power-system stability, he said. The amount of carbon-dioxide reduction also depends on the time of day the vehicles are charged, as time of day determines whether more coal or cleaner natural gas is being used to generate electricity."
Take the first one. To quote:
Doing the Math
According to the Energy Information Administration, for every 35 miles that the average compact car (25mpg) travels, it emits approximately 28 pounds of carbon dioxide. To fully charge a ZENN Car, it takes approximately 17 kilowatt hours, to propel the car its full range, 35 miles. Seventeen kilowatt hours of electricity produce 15 to 25 pounds of CO2 depending on the power plant providing the electricity. Coal-burning power plants, which make up about half of the US power grid, are the heaviest emitters of carbon dioxide. Nuclear, wind, and solar power contribute no CO2 emissions and the more they are in use, the better the numbers are in favor of EV cars.
The ZENN car is not the same as the Chevy Volt. The ZENN is limited to 25 mph with a maximum range of 30 miles. It is a NEV, not a fully featured automobile, like the Volt.
The battery pack on the ZENN is probably three or four twelve volts lashed together. The battery pack on the Volt will have to have five times the capacity, because the Volt weighs twice as much, goes twice as far, at three times the maximum speed. So they are not really comparable.
So, you have to take that 15 - 25 kilowatt hours and make it 75-125 kilowatt hours, right off the bat. So, we are already three to five times the 28 pounds of CO2 emitted by the compact car.
Also, you reference does not account for transmission losses, which can be as high as 50%, depending on the location. Add another 75 kilowatt hours, and you are getting to ten times the 28 pounds of CO2 emitted by the typical compact car.
Your reference was being fundamentally dishonest by comparing conventional cars and NEVs, and pretending they were the same thing. If you were to use a conventional car exactly like an NEV, they might have a point, but it's apples and oranges.
Then they compound their dishonesty by neglecting to add one of the major losses, transmission, into the electrical equation.
Don't believe everything you read. Particularly from people who are hawking electric cars.