There is no such thing as an “environmentally friendly vehicle”. The environment is totally quiet on vehicles.
The smelting of the steel that goes into the construction of the vehicle, no matter HOW it is powered, the refining of the various elements that go to make up the components of this engineering marvel known as an “automobile”, and the sheer volume of the machining and forging of the parts, all consume as much or more total number of BTUs as that vehicle shall ever consume while proceeding down the highway.
BTUs translate directly into “energy consumption” and result in much carbon production and excess heat generation while that energy is being released to create the very wealth that has lifted the entire human population out of the caves and trees and tribal societies from whence they sprang. The thing is, earth has proven over and over again that the “excess” carbon production and the “excess” heat are both taken in stride by the natural homeostatic forces that act in our biosphere, and at every level from the depths of the ocean to the top of our stratosphere.
The “excess” carbon, in the form of carbon dioxide, is plant food, and as such, expands and enriches the opportunities for more rapid plant growth. The “excess” heat is radiated off every night by the actions of the earth turning away from the “hot” side, exposed to the sun, and allowing the heat to be re-radiated from the “cold” side, away from the intense rays of the sun. And along with this heat energy, any little bit of “excess” heat produced by the efforts of mankind are radiated away as well.
The heat from man's activities are trivial, about 20 TW. The sun's power is 80,000 TW and you are right that it is radiated away day and night. The power from manmade CO2 (280 ppm to 410 ppm) about 900 TW. Realitistically a doubling of CO2 will produce 2,000 TW The average hurricane dissipates 600 TW (more than that for a major hurricane), part of the 40,000 TW from latent heat transfer. Small changes in the water cycle changes the latent heat number and results in global warming and global cooling. That's up to 0.2C in a matter of weeks in conjunction with ocean heat exchanges.
In short the natural effects on global temperature are far more significant than the manmade effects.