How do greenhouse gasses contribute to global warming?
To understand the mechanism behind global warming, it’s important to go into some physics and chemistry.
First up, chemistry. Carbon on earth can be divided to carbon in the atmosphere as part of the CO2 or CH4 molecule, and carbon stored in organic form which is in solid or liquid form. Organic carbon is the foundational building block of of molecules that make up all living material. It is stored in form of all living beings or dead decomposing matter, organic matter in the soil, or fossilised remains of plants (fossil fuels). Oil, coal and natural gas are made of organic matter such as trees or algae decomposing on ocean beds over millions of years.
Plants are capable of conducting a sensational chemical process called photosynthesis, which uses sun’s light to turn CO2 in the atmosphere into organic matter. This is how plants grow and get most of their weight; approximately 50% of the dry mass of the tree is carbon taken up from the atmosphere. Science still hasn’t figured out out how to replicate this process good enough to use it for our energy needs, even though it would be very desirable as a practical and eco-friendly energy source.
There is a natural balance between the CO2 in the atmosphere and the organic matter found on, or under the surface. Plants grow, taking up CO2, and then decompose or sometimes burn releasing CO2, but the balance remains the same and percentage of CO2 in the atmosphere has remained at a steady level of just under 0.3% for thousands of years. That is, until the humans came in and started massively burning the stored fossil fuels, cutting down forests or tilling soil in intensive agriculture. This releases all the stored carbon into the air, increasing the concentration of CO2 in the atmosphere. By 2021, the percentage of CO2 has reached 0.419%, which is more than a 40% increase since before the industrial revolution.