We did do that experiment once before. We grounded the entire US air fleet following 9/11. https://globalnews.ca/news/2934513/empty-skies-after-911-set-the-st

We did do that experiment once before. We grounded the entire US air fleet following 9/11. https://globalnews.ca/news/2934513/empty-skies-after-911-set-the-stage-for-an-unlikely-climate-change-experiment/ https://globalnews.ca/news/2934513/empty-skies-after-911-set... https://www.wired.com/2002/05/hot-on-the-contrails-of-weather/ https://www.wired.com/2002/05/hot-on-the-contrails-of-weathe... https://edition.cnn.com/2002/TECH/science/08/07/contrails.climate/index.html https://edition.cnn.com/2002/TECH/science/08/07/contrails.cl... https://www.bbc.co.uk/sn/tvradio/programmes/horizon/dimming_trans.shtml https://www.bbc.co.uk/sn/tvradio/programmes/horizon/dimming_... > NARRATOR: For 15 years Travis had been researching an apparently obscure topic, whether the vapour trails left by aircraft were having a significant effect on the climate. In the aftermath of 9/11 the entire US fleet was grounded, and Travis finally had a chance to find out. > ... > DR DAVID TRAVIS: We found that the change in temperature range during those three days was just over one degrees C. And you have to realise that from a layman's perspective that doesn't sound like much, but from a climate perspective that is huge. > NARRATOR: One degree in just three days no one had ever seen such a big climatic change happen so fast. This was a new kind of climate change. Scientists call it Global Dimming. Two years ago most of them had never even heard of it, yet now they believe it may mean all their predictions about the future of our climate could be wrong. The trail that would lead to the discovery of Global Dimming began 40 years ago, in Israel with the work of a young English immigrant called Gerry Stanhill. A trained biologist, Gerry got a job helping to design irrigation schemes. His task was to measure how strongly the sun shone over Israel. The thing with contrails (and we can turn it up by running rich) is that we have seen that we can turn this on (and off) relatively fast (days). -- Further reading: https://en.wikipedia.org/wiki/Global_dimming https://en.wikipedia.org/wiki/Global_dimming