Maybe it would hel if you knew where the natural gas (methane) came from. Some of it was imported to earth during planet formation by frozen methane meteors.
After our sun was born in Orion (we are leaving Orion at 19.5 kilometers per second toward Hercules) and the planets formed earth had a 750 psi atmosphere much like Jupiter and Saturn. Venus still has a 117 PSI atmosphere--mostly carbon dioxide. After we left Orion into the cold of empty space Earth froze up for a billion years. It is known as the Huronian Glaciation with ice sheets over a mile deep covering the oceans. Sunlight could not break through an atmosphere extending more than 2,500 miles above Earth. [right now our atmosphere goes up about 50 miles and is 14.5 PSI.]
Eventually we drifted between two much larger two-solar-mass stars Procyon and Sirius. Each of these stars has white dwarfs that put out more than 100 times the light of our sun in the invisible UV 350 to 400 nanometer frequency which is ideal for plant growth. Little Sirius B, the size of the earth with 1.5 solar masses and more gravity than our sun came around and put us in a tight 1/20 light year orbit around Sirius. The light and heat from these giant stars melted the ice caps on Earth and for the next 700-million years there was no ice caps. Earth had an average temperature was 60 to 80 degrees Fahrenheit. Right now it is 32 degrees--the freezing point and we are still in an ice age with ice caps at the poles.
During the 700-million year period when we were part of the Sirius system the intense light from multiple stars took our atmosphere down to 14.5 PSI with photosynthesis laying down layers of coal, oil, methane and limestone. These things are made from carbon. You can't make them without carbon and the most abundant source of carbon was Earth's 750-psi atmosphere.
You are made of carbon and you eat foods manufactured by plants from carbon dioxide. Now carbon dioxide is only .033% of our atmosphere and it is necessary to grow gardens and feed people. We need more of it. It is probably our duty to release as much of it back into the atmosphere as we can but if humans were some how able to double the CO2 in the atmosphere it would still be a trace gas at .066%. www.GuardDogBooks.com