Are EV's "Green"?

[LeftieBiker]

The cycle of life - the entire biosphere here on earth - is essentially a closed system. And the Laws of Physics say that NO energy or material can be created or destroyed.

It's not really a closed system, though. Energy from the Sun enters it in vast amounts every day, and vast amounts get radiated back into space at night. Meteors deposit some carbon in the atmosphere, and we even manage to put a little into space ourselves. So the problem is with 'carbon balance' rather than anything having to do with a genuinely closed system. People do seem determined to bring back the Age of the Dinosaurs, climate-wise, though...

 

[oilerlord]

When the plant dies, OR if it is eaten, the same amount of carbon eventually makes it's way back into the air. And the oxygen is breathed in by animals, and use it with the carbon in our food to grow. We breathe out carbon dioxide, that is then used by plants.

Thank you. This lead me to an "aha" moment. We all have internal furnaces that burn carbon-based material to create energy...like mini, individual forest fires within all of us. A forest fire merely releases stored CO2 from trees. All we're doing is essentially releasing the CO2 that was originally sequestered by the food we eat. The CO2 remains in balance. I get it now.

 

[LeftieBiker]

When the plant dies, OR if it is eaten, the same amount of carbon eventually makes it's way back into the air. And the oxygen is breathed in by animals, and use it with the carbon in our food to grow. We breathe out carbon dioxide, that is then used by plants.

Again, not that simple. Some of the dying plants end up as peat, then coal or oil. Some are stored for thousands of years in long-lived trees. And, speaking of 'Ah Ha Moments', plants breathe in oxygen and give off CO2 at night...

 

[oilerlord]

Again, not that simple. Some of the dying plants end up as peat, then coal or oil. Some are stored for thousands of years in long-lived trees. And, speaking of 'Ah Ha Moments', plants breathe in oxygen and give off CO2 at night...

No, I knew that one. I think it's still pretty simple. It's about maintaining an O2 / CO2 balance.

In terms of humans contributing to the rise in CO2 - just by merely existing - I can see how we are essentially carbon neutral. We eat carbon-based matter, burn it as energy, and release CO2 - the concept being about the same as lighting a head of lettuce on fire - releasing the CO2 it stored over the month or two it was growing.

Of course if we burned trees that were around for "thousands of years", that would suddenly release / introduce the CO2 that was sequestered thousands of years ago. Not much different than burning fossil fuels.

 

[LeftieBiker]

Redwoods and other trees can and do live for thousands of years. No need for quotation marks. And while our basic metabolism may be roughly carbon neutral, our actions, including things we do to raise food (like clearing forests) are increasing the carbon in the atmosphere. So as our population increases, the CO2 level increases. This may not be unavoidable, strictly speaking, but it's what actually happens.

 

[oilerlord]

I think we're debating the same side of the debate. We drove through the redwood forest last year. Amazing sight. I actually had my wife take a picture of me hugging one of those gargantuan trees . Of course, my arms needed to be a lot wider, but I digress.

I was looking into how humans factored into CO2 (again by simply breathing). Answers were posted that made sense. While I'm sure the semantics can be argued, I believe the basic premise is sound.

 

[NeilBlanchard]

And, speaking of 'Ah Ha Moments', plants breathe in oxygen and give off CO2 at night...

Huh? How/why do plants take in oxygen and give off carbon dioxide at night?

 

[oilerlord]

Huh? How/why do plants take in oxygen and give off carbon dioxide at night?

Photosynthesis only happens during the day. At night, plants do release a small amount of CO2.

"Interestingly, in order to maintain their metabolism and continue respiration at night, plants must absorb oxygen from the air and give off carbon dioxide (which is exactly what animals do). Fortunately for all of us oxygen breathers, plants produce approximately ten times more oxygen during the day that what they consume at night."

http://scienceline.ucsb.edu/getkey.php?key=2860

 

[LeftieBiker]

Yes. Plants have to use oxygen to release energy from carbohydrates just like other organisms, releasing CO2 in the process. They just produce so much more oxygen from photosynthesis that it isn't noticed in the daytime.

I was taught this in an otherwise mediocre Catholic school primary education. I've since been surprised at how few people actually learn it. Heck, maybe I learned it in my own reading as a child...