What are the main greenhouse gases?
The world keeps talking about CO2 all the time, so one can be excused for thinking that it is the only greenhouse gas.
Not so. There are many other greenhouse gases that contribute to global warming, though their overall contribution is significantly lesser than that of CO2 – and that indeed is why CO2 gets all the attention.
Now, what are the other greenhouse gases?
The main greenhouses gases that are responsible for global warming are listed below.
- Carbon Dioxide (CO2)
- Methane (CH4)
- Nitrous Oxide (N2O)
- CFC-12 (CCl2F2)
- HCFC-22 (CCl2F2)
- Sulfur Hexaflouride (SF6)
The global warming potential of the greenhouse gases are listed below. The global warming potential is a relative grading, where CO2 gets a value of 1.
- Carbon Dioxide (CO2) – Global Warming Potential of 1
- Methane (CH4) – 25 (implies methane, for the same volume, has 25 times the global warming potential as CO2)
- Nitrous Oxide (N2O) – 298
- CFC-12 (CCl2F2) – 10900
- HCFC-22 (CCl2F2) – 1810
- Sulfur Hexaflouride (SF6) – 22800
In fact, the above potential has been worked out based on the inherent properties of the greenhouse gases, as well as the amount of time they stay in the atmosphere. The duration for their stay is important as well – for instance, if a packet of CO2 stays in the atmosphere only for 1 year and another packet with the same volume stays for 100 years, the global warming potential for the latter packet is 100 times that of the former packet, even though both contain the same gas in the same volume.
So, how long indeed do the various greenhouse gases stay in the atmosphere?
The main greenhouses gases, and their atmospheric lifetime in years.
- Carbon Dioxide (CO2) – 70-80% will stay for approx. 100 years, while the rest could linger on for much, much longer durations.
- Methane (CH4) –12
- Nitrous Oxide (N2O) –114
- Ozone (O3) – hours-days
- CFC-12 (CCl2F2) –100
- HCFC-22 (CCl2F2) –12
- Sulfur Hexaflouride (SF6) –3200
