From Jan Poller
These scientists made their own clouds, and what they found could require us to rethink how fast the earth is warming.
A new experiment looking at clouds is about to change the way we think about climate change.
For decades, scientists have thought that the tiny particles that form clouds — and play a big role in keeping the planet cool — were produced as a counterintuitive side effect of pollution.
So, while it was understood that we were putting loads of planet-warming gases into the atmosphere and heating things up, it was also thought that at least some of those particles were getting trapped inside clouds and helping to keep that warming from being even more catastrophic.
But a study published on Wednesday in the journal Nature, which looked more closely at these tiny particles, found that they can be produced naturally. This will help us understand just how cloudy the world actually was before we started polluting it, which is key to figuring out the rate at which our planet is heating up.
A cloud conundrum
The Intergovernmental Panel on Climate Change (IPCC) recognizes aerosols as the single biggest source of uncertainty in human-driven climate change. Part of the problem is that we have no way of measuring just how cloudy the planet was in the preindustrial era.
Thanks to this uncertainty, and despite our precise measurements of the effects of human-induced greenhouse warming on climate, the estimates for projected climate change have entertained a wide range of numbers for projected warming, and these numbers haven’t changed for the past 35 years.
The models predict that if carbon dioxide doubles over the next century, then the planet will warm anywhere from 2.7 to 8.1 degrees Fahrenheit — a critical difference that should inform the way we prepare for the future.
So, what’s the deal with aerosols? Turns out that there are two sources of the particles: