What is the runaway greenhouse effect? What planets does it work on and what are the consequences?

Question

Josephine Allen · Accepted Answer

"Runaway Greenhouse Effect" is the positive feedback cycle that continuously raises an atmosphere's temperature to some new equilibrium point.

The planetary climate(s) and the capacity of life to persist may be significantly impacted by a new equilibrium temperature point, but it cannot go on indefinitely because that is not how the mass and energy balances operate. A planet needs enough star energy and an atmosphere rich in heat-absorbing substances to start and fuel an unstable runaway greenhouse effect. It takes a normal, balanced greenhouse effect to keep life on Earth going. Venus could serve as a useful illustration of an accelerated greenhouse effect that has reached a new equilibrium.

Isaac Ayoub · Answer

undefined The runaway greenhouse effect is a scenario in which a planet's atmosphere becomes so thick with greenhouse gases that it traps an excessive amount of heat from the sun, leading to a rapid increase in temperature. This process results in a positive feedback loop, where higher temperatures cause more evaporation of water and release of greenhouse gases, further exacerbating the warming.

This phenomenon has been observed on Venus, where the surface temperature exceeds 450 degrees Celsius (842 degrees Fahrenheit) due to its dense atmosphere primarily composed of carbon dioxide. The runaway greenhouse effect is also a concern for Earth, as continued emissions of greenhouse gases could potentially lead to a similar scenario, albeit on a slower timescale.

The consequences of a runaway greenhouse effect include the loss of surface water, extreme heat, and the breakdown of the planet's habitability for life as we know it. It would render the affected planet inhospitable to most forms of life, making it an important consideration in discussions about climate change and planetary habitability.