Scientists from the Florida Institute of Technology have published a study indicating that waste heat could lead to fatal overheating of the planet for advanced civilizations within just 1,000 years. Since the Industrial Revolution, the Earth’s average global temperature has steadily increased. According to the National Oceanic and Atmospheric Administration (NOAA), the Earth has warmed 0.06°C per decade since 1850.
Since 1982, this trend has accelerated, with the average annual temperature increase now standing at 0.20°C. These changes are primarily attributed to greenhouse gas emissions from fossil fuels. However, even if human civilization ceases using fossil fuels, researchers argue that waste heat alone could pose a significant threat.
Soviet climatologist Mikhail I. Budyko highlighted this issue in 1969, suggesting that industrial processes and energy production would eventually contribute significantly to global heating. Waste heat contributes only a minor portion to global warming compared to greenhouse gases.
Yet, long-term projections show that this situation could change swiftly.
Waste heat threatens future civilizations
If the current rate of energy production and consumption continues, waste heat could result in an additional 1°C temperature increase by the end of the century, independent of fossil fuel use.
Scientists used modeling techniques to understand how long it would take for a civilization to overheat its planet. They adapted habitability zone calculations for exoplanets to include an additional heat source from technological activities. They also considered the exponential growth in civilizations and energy consumption, as predicted by the Kardashev scale.
Using historical data, scientists noted that from 1800 to 2023, global energy consumption increased from 5,653 terawatt-hours (TWh) to 183,230 TWh, mirroring population growth. By extrapolating this trend, they determined that an advanced civilization could only sustainably exist for about 1,000 years after entering a period of exponential growth before the planet becomes uninhabitable due to waste heat. To prevent such an outcome, advanced civilizations could employ several strategies.
Potential methods are shielding to reduce the radiation flux from the star, relocating technological infrastructure off-planet, or consciously reducing energy consumption by slowing growth. However, whether a technologically advanced civilization can “stop” its progression in time remains an open question. This study provides insights into the future of Earth and impacts the search for alien civilizations, suggesting that overheating from waste heat might explain the lack of observable advanced extraterrestrial societies.
