To prevent further global warming, it is hoped that we can capture and store CO_2 so that it is not released into the atmosphere. Since we extract fossil fuels (oil, gas) from the ground, one proposed way of storing the CO_2 is to pump it into old, disused oil and gas fields that have been exploited.
I put most of the carbon in my belly. Us and our food are carbon based and this area of study is called organic chemistry. There are some theories that it could be possible for some alien life to be something other than carbon based. The closest thing to carbon (in terms of atomic structure) is silicon. So if we find aliens we might find silicon based creatures. It would be very easy then to combine technology with life since all our technology is silicon based.
If you were referring to CO2 emissions in the atmosphere then the best place to put it would be in the Mars atmosphere. Global warming is a problem here on Earth, but it would be ideal for terraforming the Martian atmosphere to make it habitable for humans.
Carbon is in pretty much everything! Which is good for us as we can use something called “carbon dating” which uses the decay of an isotope of carbon (variation of carbon) to measure the age of things. This is precisely how we have estimated an age for the Earth, using carbon dating to test the age of rocks on Earth’s surface.