Significance of a one-degree Celsius increase in global temperature

TL;DR

A simple physics-based analysis demonstrates that a one-degree Celsius rise in global temperature results in a vast excess energy pool capable of driving extreme weather events, highlighting the significance of even small temperature increases.

Contribution

The paper provides an accessible, physics-based estimation linking a one-degree temperature increase to the energy capable of powering extreme weather, clarifying the significance of global warming.

Findings

Excess thermal energy from a one-degree increase is thousands of times larger than energy needed for hurricanes.

Small temperature increases can lead to large energy pools capable of extreme weather.

Simple physics calculations can illustrate the plausibility of climate change impacts.

Abstract

The Intergovernmental Panel on Climate Change reports indicate that the global mean temperature is about one-degree Celsius higher than pre-industrial levels, that this increase is anthropogenic, and that there is a causal relationship between this higher temperature and an increase in frequency and magnitude of extreme weather events. This causal relationship seems at odds with common sense, and may be difficult to explain to non-experts. Thus to appreciate the significance of a one-degree increase in global mean temperature, we perform back-of-the-envelope calculations relying on simple physics. We estimate the excess thermal energy trapped in the climate system (oceans, land, atmosphere) from a one-degree Celsius increase in global mean temperature, and show that it is thousands of times larger than the estimated energy required to form and maintain a hurricane. Our estimates show that global warming is forming a very large pool of excess energy that could in principle power heatwaves, heavy precipitation, droughts, and hurricanes. The arguments presented here are sufficiently simple to be presented in introductory physics classes, and can serve as plausibility arguments showing that even a seemingly small increase in global mean temperature can potentially lead to extreme weather events.