double the amount as planes.
i dont know do the math
Too much !
1% of the worldds emissions
some, but much less than the amount it absorbs. Also, as an alternative to fertilizer, it reduces co2 (fertilizer production admits a lot of co2)
Animals emit CO2 when they exhale.
It absorbs Co2 through the process of Photosythisis.
No. Plants emit their own CO2 through respiration.
Yes, infact vehicles are considered to be the main contributor to the Co2 in the atmosphere
Once a flower is cut and starts dying it does emit CO2 as it decomposes.
It depends on the model. A typical truck emits 30 or more POUNDS of CO2 for 15-20 miles.
Hardly any at all ... hard to believe from what we perceive as exhaust emitting from their tall pipes, but some semi trucks emit less emissions than some older passenger cars.
Co2 is not needed for animal life, in fact it is poisonous. They breathe it out as a by product from using energy. However, plants must have co2, and emit oxygen as a by product.