The environments of worlds are constantly changing for many different reasons. And here on Earth, some of those reasons are us. Understanding how humans are causing our world to change is an ongoing struggle, and the more we look, the more complexity we find. The Nobel Prize for Physics went to the complex system analysis that was needed to just start to understand Climate change!

Part of what makes everything so complicated is the need to understand the thermodynamic properties of everything sunlight touches. On the surface of our world, we have to understand how sunlight is reflected and absorbed by plants, lakes, oceans, ice, snow, dirty snow, deserts, and everything. Above our world, we have to understand the roles of clouds, pollutants, and naturally occurring junk like ash at every altitude. And at every point around our world.

Sunlight and the atmosphere interact in different ways in different parts of our atmosphere and affect the weather and the flow of heat in different ways. New research published in the journal Science Advances and led by Marc Mallet finds that some of the most used climate models fail to fully factor in the effects of aerosols from burning biomass – the burning of forests and savanna to make way for agriculture, as well as the burning of agricultural waste. 

When you burn biomass, brown and black carbon is released as aerosols and can rise up through the atmosphere. These dark particles hold onto the Sun’s heat and warm the surrounding atmosphere. This study looked specifically at biomass burning in Central Africa and the effects it had in the Southeast Atlantic and the northern African weather. They find that current models are not able to reproduce the strong warming effect seen at the top of the atmosphere and under-predict the formation of low-level clouds which are important in calculating the Earth’s balance between reflecting and absorbing sunlight.

Put another way, aerosols are heating the upper atmosphere, but they are also part of the reason more clouds are forming than predicted, and those clouds reflect incoming sunlight. This is a complex system, and to get a handle on it, they point out that measurements from aircraft yield more accurate data for models.

This all feels kind of far away from our studio here in the middle U.S., but if you find that weather predictions aren’t as accurate as they used to be, what you’re seeing is a combination of we don’t have the same quality data we used to have and as climate change ramps up, our past understanding of the atmosphere no longer applies. The next decades are going to be difficult for meteorologists and heartbreaking for many who have to live through the planet’s harsher storms and more extreme temperatures.

More Information

University of Exeter press release

“Climate models generally underrepresent the warming by Central Africa biomass-burning aerosols over the Southeast Atlantic,” Marc Mallet et al., 2021 October 8, Science Advances