The table below lists information about several greenhouse gases: their typical atmospheric lifetime and their 100-year Global Warming Potential (GWP), which compares their warming effect to that of carbon dioxide.
| Greenhouse gas | Typical atmospheric lifetime (years) | Global Warming Potential (100-year GWP) |
|---|---|---|
| Carbon dioxide (CO2\text{CO}_2CO2) | 50 – 200 | 1 |
| Methane (CH4\text{CH}_4CH4) | 12 | 28 |
| Nitrous oxide (N2O\text{N}_2\text{O}N2O) | 121 | 265 |
| CFC-12 (CF2Cl2\text{CF}_2\text{Cl}_2CF2Cl2) | 100 | 10200 |
(i) Which gas in the table has the greatest warming effect per unit mass over 100 years?
(ii) Name a greenhouse gas that is not listed in the table.
The greenhouse impact of any gas is determined by factors including:
(i) Nitrous oxide (N2O\text{N}_2\text{O}N2O) has a significantly higher GWP than carbon dioxide (CO2\text{CO}_2CO2). Suggest why carbon dioxide still contributes much more to overall global warming.
(ii) Suggest why it has been possible to successfully phase out CFC-12 internationally, while reducing carbon dioxide emissions remains extremely challenging.
(iii) State two methods humans can implement to reduce emissions of carbon dioxide into the atmosphere.
Describe two specific ways that global warming can impact animal habitats.
