# Geothermal power plants: Impact on the biosphere

Rotten-egg gas, sinking ground and the occasional earthquake

Source page: https://www.materialinsights.org/energy/e_geo_power/biosphere/

What this tab covers Effects on human, animal, plant, fungal and microbial life and on whole ecosystems: in the short term (construction and early years), medium term (operating life) and long term (decommissioning and legacy).

Geothermal plants have few deaths or air-pollution effects compared with fossil fuels, but they can release CO2 and hydrogen sulphide from the reservoir, cause ground subsidence and occasionally trigger earthquakes.
 Operational CO2, global average about 121 g CO2/kWh reported (some Turkish plants 400-1,300)^[6](https://openknowledge.worldbank.org/entities/publication/22e105c7-550f-531d-8e2c-4011098ecf54) Life-cycle greenhouse gas emissions 38 g CO2e/kWh median (range 6-79)^[5](https://www.ipcc.ch/site/assets/uploads/2018/02/ipcc_wg3_ar5_annex-iii.pdf#page=7) Maximum subsidence, Wairakei, New Zealand about 15 m after 50 years^[12](https://www.usgs.gov/publications/update-subsidence-wairakei-tauhara-geothermal-system-new-zealand) H2S removed by abatement systems over 99.9%^[9](https://www.ourenergypolicy.org/wp-content/uploads/2016/02/Environmental-Guide.pdf)

#### Effects over time

| Life affected | Short term | Medium term | Long term |
|---|---|---|---|
| **Humans**^[9](https://www.ourenergypolicy.org/wp-content/uploads/2016/02/Environmental-Guide.pdf)^[12](https://www.usgs.gov/publications/update-subsidence-wairakei-tauhara-geothermal-system-new-zealand) | Drilling noise and construction traffic. | Hydrogen sulphide (rotten-egg gas) is toxic at high concentration; abatement removes over 99.9%. Subsidence damages buildings and pipes. | Low-level arsenic and boron in waste must be contained. |
| **Animals**^[9](https://www.ourenergypolicy.org/wp-content/uploads/2016/02/Environmental-Guide.pdf) | Habitat disturbance at well pads. | Little evidence of effect beyond the site. | Little evidence of effect. |
| **Plants**^[9](https://www.ourenergypolicy.org/wp-content/uploads/2016/02/Environmental-Guide.pdf) | Clearing for pads and pipelines. | Little evidence of effect beyond the site. | Little evidence of effect. |
| **Fungi and soil life**^[9](https://www.ourenergypolicy.org/wp-content/uploads/2016/02/Environmental-Guide.pdf) | Little evidence of effect. | Little evidence of effect. | Little evidence of effect. |
| **Ecosystems**^[3](https://geysers.com/water)^[12](https://www.usgs.gov/publications/update-subsidence-wairakei-tauhara-geothermal-system-new-zealand) | Small footprint: well pads, pipelines and plant. | Reservoir pressure declines if extraction outpaces recharge, as at The Geysers; Wairakei subsided about 15 m over 50 years. | Reinjection can partly restore reservoirs; subsidence is permanent. |

#### How the effects are reduced

Reinjecting spent fluid maintains pressure and limits subsidence; H2S abatement converts the gas to sulphur; binary plants that reinject all fluid emit almost nothing. Directional drilling from shared pads reduces land use, and air cooling avoids fresh-water use in dry regions.

#### Sources

1. [The Geysers: Water (steam field recharge)](https://geysers.com/water) Calpine (geysers.com), 2024
2. [Climate Change 2014: Mitigation, Annex III Technology-specific cost and performance parameters, Table A.III.2](https://www.ipcc.ch/site/assets/uploads/2018/02/ipcc_wg3_ar5_annex-iii.pdf#page=7) IPCC AR5 Working Group III, 2014
3. [Understanding CO2 Emissions from Geothermal Power Generation in Turkey (Live Wire 2021/118)](https://openknowledge.worldbank.org/entities/publication/22e105c7-550f-531d-8e2c-4011098ecf54) World Bank, 2021
4. [A Guide to Geothermal Energy and the Environment](https://www.ourenergypolicy.org/wp-content/uploads/2016/02/Environmental-Guide.pdf) Geothermal Energy Association, 2007
5. [Update on subsidence at the Wairakei-Tauhara geothermal system, New Zealand (Allis, Bromley and Currie, Geothermics 38)](https://www.usgs.gov/publications/update-subsidence-wairakei-tauhara-geothermal-system-new-zealand) Elsevier (USGS Publications Warehouse record), 2009

## Other sections

- [Summary](https://www.materialinsights.org/energy/e_geo_power/index.md)
- [Overview](https://www.materialinsights.org/energy/e_geo_power/overview/index.md)
- [Correlation](https://www.materialinsights.org/energy/e_geo_power/correlation/index.md)
- [Efficiency](https://www.materialinsights.org/energy/e_geo_power/efficiency/index.md)
- [Techniques](https://www.materialinsights.org/energy/e_geo_power/techniques/index.md)
- [Resources and labour](https://www.materialinsights.org/energy/e_geo_power/resources/index.md)
- [Relationships](https://www.materialinsights.org/energy/e_geo_power/links/index.md)