Physics of Climate Change
Understanding all of climate change, and what it means to each community, is an impossible task. However, it is much easier to understand the principles behind climate change, and apply those principles into specific areas and contexts. Perhaps the first visualization taught about climate change is that of a blanket (Exploratium, NASA). When you are cold, covering yourself with a blanket is common sense. Yet, a blanket doesn’t work by being warm itself. It works by trapping in heat that you release naturally, slowly warming you up. The atmosphere works in much the same way.
Energy within our solar system starts with the sun, which provides heat and warmth to Earth in the form of shortwave radiation. This energy can effectively cut through our atmosphere, providing warmth to plants, animals, and the surface itself. However, when the sun has gone down, the Earth does not immediately freeze! It retains that warmth, and slowly emits it back into space in the form of longwave radiation. However, when this energy seeks to escape the atmosphere, it finds it much more difficult! It finds, much like the heat from your body finds the blanket and remains trapped, that the gasses that comprise the atmosphere are trapping it in. The different gasses and compounds (known as greenhouse gases, more below) do this more or less effectively and have done so for billions of years. Climate change acts and exists because as the composition of the atmosphere changes, such as adding carbon dioxide, we are effectively adding more blankets. The more blankets we add, the more heat remains trapped, and the warmer the planet becomes. This is the core understanding of climate change, and everything else comes from this concept.
However, due to the connected nature of our atmosphere and planet, changing the amount of energy trapped within the atmosphere affects every aspect of weather, climate, and life. Hotter days change how water evaporates, while a warmer atmosphere allows for more moisture to be contained within it. Warmer atmospheres with more moisture create greater potential for extreme weather events, and so on (Adam, 2023). Many of these connections are easy to understand while others, such as disease spread and natural disasters, are more complicated and are a core focus of many researchers (e.g. Phillips et al 2024, Sauerborn and Ebi 2012).