Table 2.
Comparative advantages and constraints of biotic versus abiotic options.
| parameters | biotic (terrestrial) | abiotic (engineering) |
|---|---|---|
| the process | natural (photosynthesis, humification) | engineering (capture and injection) |
| sink capacity | finite (50–100 Pg) | extremely large (thousands of Pg) |
| time horizon | immediate, for next 25–50 years | 10–20 years from now, for long period |
| cost | negative, none or low | High |
| risks | ||
| NPP and biomass yield reduction | minor or low | N.A. |
| human health | minor to low (agricultural chemicals) | High |
| environmental | positive effect (win-win, no-regret) | high |
| leakage | none or small (by ploughing, etc.) | complex and expensive methods |
| monitoring and verification | simple and routine methods | complex and expensive methods |
| regulatory measures | monetary incentives may be helpful | legislative and policy measures essential |