Chapter 1: Understanding Thermal Pollution

The alarming effects of climate change are becoming increasingly evident, highlighting the urgency of the crisis. Often, it takes a significant life event—like an illness or a breakup—for individuals to change their behaviors. Similarly, the climate crisis has prompted many to consider more sustainable alternatives, such as green energy sources instead of fossil fuels.

Green energy refers to natural and renewable energy sources, which replenish quickly or even before they are fully utilized. Common examples include sunlight (see further reading: How Solar Energy Technology Is Advancing), water, and wind, while less conventional sources encompass microalgae (see further reading: Exploring Microalgae as a Sustainable Fuel) and ocean waves (see further reading: The Benefits of Wave Energy).

An intriguing yet often overlooked energy source is geothermal heat. This heat can naturally arise from the Earth's core or be artificially accumulated through urbanization and industrial activities, leading to what we term thermal pollution. This form of heat pollution can be assessed by comparing groundwater temperatures in affected areas to those in unpolluted rural regions. The accumulation of heat can often be traced back to heat loss from buildings and the warming effects of sunlit sealed surfaces like asphalt.

To harness this heat, extraction methods can be employed. For instance, water can be drawn from groundwater wells and pumped through a heat pump to capture the heat. Alternatively, heat can be extracted from the soil using fluids in boreholes. This principle is further elucidated in the following video, which explains the mechanics of naturally occurring geothermal heat:

1. Advantages Over Other Green Sources

Recycling thermal pollution offers several benefits compared to other renewable energy sources:

• The heat is consistently available and unaffected by weather conditions.
• It is generated and utilized within the same locality, minimizing energy transportation distances.
• Extracting this heat does not disrupt aquatic ecosystems.
• Heat can be harvested over extended periods—often, digging just 20 meters (approximately 66 feet) deep can provide enough heat for a year.
• It generates no CO2 emissions.

2. Mitigating Heat Pollution

Recycling thermal pollution also contributes to reducing heat pollution by restoring groundwater temperatures to levels comparable to those found in unpolluted areas. Ongoing management is necessary to prevent the reaccumulation of heat. This approach not only serves as a renewable energy source but also plays a crucial role in preserving ecosystems dependent on high-quality groundwater. Healthy ecosystems, such as wetlands, can sequester significant amounts of carbon dioxide (CO2), helping combat climate change.

For further insights, see:

• 4 Ways To Protect Natural Ecosystems and Save Our Planet
• How Soil Biodiversity Enhances Our Health and Planetary Well-being

Section 1.2: Scaling Up Thermal Pollution Recycling

Currently, subsurface heat recycling occurs on a limited scale. However, many heat-polluted locations have the potential for larger-scale implementations. Sites that lose heat or have minimal demand for recycled heat may not be suitable, whereas those meeting over 25% of annual heating needs could benefit from scaling up. Each potential location should be assessed individually to determine the viability of expanding small-scale systems into larger ones.

For example, my home is heated using wood pellets—a more sustainable option than fossil fuels. However, utilizing subsurface heat would be an even greener alternative (further reading on wood burning: 4 Ways To Protect Natural Ecosystems and Save Our Planet).

Chapter 2: The Role of Thermal Pollution in Climate Mitigation

As air temperatures rise due to global warming, the atmosphere is increasingly warmer than the ground, which in turn heats the ground. By recycling the heat stored underground, we can cool the ground and allow it to absorb new heat from the atmosphere. This means that as global warming intensifies, the importance of recycling subsurface heat will grow.

Conclusion

In summary, recycling thermal pollution presents a more eco-friendly energy alternative compared to non-renewable sources and offers advantages over other green energy options. It aids in heat pollution removal, can be scaled up, and contributes to atmospheric cooling amidst worsening global warming.

Call to Action

Here are some practical steps that individuals can take to combat heat pollution:

• Insulate homes effectively.
• Replace paved garden areas with vegetation.
• Utilize industrial heat waste for residential heating.
• Plant trees for shade.
• Create a pond that uses subsurface heat to cool the surrounding area through evaporation.

What other ideas do you have for preventing heat pollution? Please share your suggestions in the comments to inspire collective action.

Credit

This article draws from:

Benz, S. A., Menberg, K., Bayer, P., & Kurylyk, B. L. (2022). Shallow subsurface heat recycling is a sustainable global space heating alternative. Nature Communications, 13(1), 1–11.

Chapter 3: The Plastic and Aluminum Debate

The first video titled "Why Plastic Recycling Isn't Working" explores the challenges facing plastic recycling and its environmental impact.

Another insightful video, "Is Aluminum Better Than Plastic? It's Complicated," examines the complexities of comparing aluminum and plastic in terms of environmental sustainability.