How much carbon does human respiration, digestion etc. contribute to global warming?

Question

How much CO2 and methane are created just by living? Given there are 6 billion people on earth it would seem like a big nummber.

Answer 1

Actually, this shows that you are thinking about the topic of global warming, and that is good.

Human respiration is "carbon neutral" meaning that it does not change the overall carbon dioxide content of the atmosphere. How can that be with over 6 and a half billion people?

The carbon dioxide we breathe out comes from breaking down molecules of our food to get the energy. The food molecules trace back through short food chains to producers or autotrophs that made food by photosynthesis. These producers took carbon dioxide from the air. This is called the short-term carbon cycle. Carbon dioxide comes out of the air into producers, consumers eat the carbon compounds and return the carbon dioxide to the air.

Think of having a bathtub full almost to the point of spilling over. The short term carbon cycle could be represented by dipping out a cup of water (plants), pouring the water into a bowl (animals eat the plants), and pouring the water back into the tub from the bowl (breathing out carbon dioxide). This does not change the level of water in the tub.

Burning fossil fuels puts carbon dioxide into the air that was taken out of the air millions of years ago when the atmosphere had a much larger carbon dioxide content. If we go back to our bathtub model, this is like discovering a closet full of jars of water that somebody saved years ago when they had a much larger bathtub. They dipped water out of the bathtub and put it away in the closet. Now we discover the jars and start pouring them into the smaller bathtub. Won't be long before we make it so full that the water runs out. That's the effect of the long-term carbon cycle.

Answer 2

I think the carbon produce by human can't contribute to global warming, the global warming is mainly cause by open burning and car exhaust that produce CO2. But there's a little chance if the population of human continue to increase.

Answer 3

Oh, for pity's sake, are we going to have to limit that,too?!!!!

Answer 4

from Repiblicans too much