This may rub people the wrong way, because I'm so tired of the ignorance around this topic, but please bear with me. I will begin by offering a tip: a quick way to tell if an article about the environment impact of EV's is full of $hi! is if the author doesn't distinguish the difference between energy consumption and pollution.
As an example, think of the difference between a gasoline and diesel internal combustion engines. The gasoline engines are typically half the thermodynamic efficiency of their diesel counterparts, but produce a quarter of the pollution (more explicitly sulphur oxides (SOx), nitrogen oxides (NOx), and particulate matter (PM), a lot of which is highly carcinogenic). That's why diesel engines are cheaper to run, but are worse for the environment. When VW did "diesel-gage", they gained 3% in overall thermodynamic efficiency at a cost of 4x more pollution!
As another example, think of generating 1 kWh of energy (I think people are more comfortable energy units of kWh than joules) from coal verses natural gas. The thermodynamic efficiency is not too far apart with coal being 33.8% efficient in Alberta (where I live) and natural gas being 44.5% efficient. That means natural gas produces about 32% more electrons than heat. However, when we talk pollution, coal produces literally millions (perhaps tens of millions) of times more pollution. And here's the kicker, coal plants are not all created equal. The difference between the best and the worst, in terms of pollution (not thermodynamic efficiency, though that's improved as well) can be a couple orders of magnitude or more!
Now here's some food for thought: a gasoline engine in a typical car is 15% thermodynamically efficient while driving down the highway (ideal conditions). In Calgary (again where I live), our city is electrically powered from 86% natural gas and 14% renewables. Remember that the natural gas is 45% thermodynamically efficient, so we're getting 3x more useful energy or 1/3 the amount of waste-heat. The gasoline engine is also producing millions to hundreds of millions of times more pollution.
Finally, remember that this is comparing energy at our power plant to gasoline already in a gas car. If you want to talk total environmental impact, I can certainly provide all the calculations and citations. Believe it or not, I'm trying to keep this as brief as possible. Needless to say, they're virtually incomparable in terms of pollution. In terms of energy consumption, the difference is still AT LEAST 5 times better.
At the end of the day, the litmus test is, how much does your EV cost you to drive a kilometer in terms of electricity? Depending on how "lead-footed" you are, what kind of ICE vehicle would you need to drive exactly the same way? What is its fuel economy? How much would that cost you? I bet you it's 5 - 20x more expensive, depending on where you live. That's because you're using 1/5 to 1/20 the amount of energy folks... never-mind the dramatically reduced pollution, even if you're 100% coal powered, because of extraction, transportation, distribution, consumption, and particulate capture (if applicable) improvements at a power plant, that simply is impossible to do between the front of an ICE engine and the tail pipe at the other end.
I could also comment on the factually incorrect comments about solar generation (and its comparison to other energy sources) and how impactful the EV battery actually is on the environment, but this is already a long enough post!
