# Passive solar and natural cooling: Impact on the biosphere

Protecting people in heatwaves without heating the planet

Source page: https://www.materialinsights.org/energy/e_passive/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).

Passive design is mostly beneficial: it avoids the electricity and refrigerant emissions of air conditioning and protects people from heat. Space cooling uses about 2,200 TWh a year and causes about 1 Gt of CO2. Specific risks are limited to water use and seawater-cooling discharge.
 World electricity for space cooling about 2,200 TWh a year^[2](https://energy-transitions.org/wp-content/uploads/2025/01/ETC_Buildings-Decarbonisation-Report_Summary_Cooling.pdf) CO2 from cooling electricity about 1 Gt a year (about 3% of global emissions)^[2](https://energy-transitions.org/wp-content/uploads/2025/01/ETC_Buildings-Decarbonisation-Report_Summary_Cooling.pdf) Share of US building primary energy used for air conditioning nearly 15%^[4](https://doi.org/10.1038/nature13883)

#### Effects over time

| Life affected | Short term | Medium term | Long term |
|---|---|---|---|
| **Humans**^[2](https://energy-transitions.org/wp-content/uploads/2025/01/ETC_Buildings-Decarbonisation-Report_Summary_Cooling.pdf) | Little evidence of harm beyond normal building risks. | Cooler interiors without electricity protect health in heatwaves; about 700 million more people could live in hot climates by 2050, and over 40% of people in hot climates may still lack cooling then. | Buildings designed for passive comfort keep working when power supply fails. |
| **Animals**^[5](https://blogs.worldbank.org/en/latinamerica/sustainable-cooling--a-deep-dive-into-seawater-air-conditioning-) | Little evidence of effect. | Seawater cooling returns deep water to the sea; South Pacific experience suggests marine life and coral reefs can thrive near outlets. | Little evidence of effect. |
| **Plants**^[2](https://energy-transitions.org/wp-content/uploads/2025/01/ETC_Buildings-Decarbonisation-Report_Summary_Cooling.pdf) | Little evidence of effect. | Planted trees are used for shading in passive cooling. | Little evidence of effect. |
| **Fungi and soil life**^[2](https://energy-transitions.org/wp-content/uploads/2025/01/ETC_Buildings-Decarbonisation-Report_Summary_Cooling.pdf) | Little evidence of effect. | Little evidence of effect. | Little evidence of effect. |
| **Ecosystems**^[2](https://energy-transitions.org/wp-content/uploads/2025/01/ETC_Buildings-Decarbonisation-Report_Summary_Cooling.pdf) | Little evidence of effect. | Avoided cooling electricity cuts power-sector emissions; refrigerant leakage from air conditioners adds about another 1 Gt CO2e a year. | With better design and efficient equipment, 2050 cooling demand could be about 1,200 TWh instead of up to 5,000 TWh. |

#### How the effects are reduced

The main risk is a design wrong for the climate: unshaded glazing overheats, and evaporative coolers waste water in humid regions. Climate-specific building codes, shading and auto-flush rather than continuous bleed-off address these. Seawater systems need assessment of the outlet so that returned water does not harm reefs.

#### Sources

1. [Buildings Decarbonisation Report: Summary, Cooling](https://energy-transitions.org/wp-content/uploads/2025/01/ETC_Buildings-Decarbonisation-Report_Summary_Cooling.pdf) Energy Transitions Commission, 2025
2. [Passive radiative cooling below ambient air temperature under direct sunlight (Raman, Anoma, Zhu, Rephaeli and Fan, Nature 515, 540-544)](https://doi.org/10.1038/nature13883) Nature, 2014
3. [Sustainable cooling: a deep dive into seawater air-conditioning solutions for the Caribbean](https://blogs.worldbank.org/en/latinamerica/sustainable-cooling--a-deep-dive-into-seawater-air-conditioning-) World Bank Blogs, 2024

## Other sections

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