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AGU Chapman conference: water vapor and climate

I’m here in Kailua Kona for the AGU Chapman conference on atmospheric water vapor and its role in climate. Given the high humidity and afternoon rain, the topic seems quite appropriate.

In the keynote lecture, Brian Soden of the University of Miami gave a great introduction to the role of water vapor in climate change. It seems to be a general consensus that there is a positive feedback between water vapor and climate. There has been an increase in water vapor in the atmosphere over the past 15 years, and Soden reported that model simulations show that greenhouse gas emissions are at least in part to blame.

He suggests that increasing atmospheric water vapor will play havoc with atmospheric circulation. Wet regions will get wetter while arid regions will dry even more. In addition, floods and droughts will become more frequent and more extreme.

Meanwhile, Laura Wilcox of the University of Reading presented results from a study of water vapor emissions from aviation. No, the irony of presenting this study in a location that required a minimum five hour flying time wasn’t lost on the participants. Wilcox found that the amount of radiative forcing from airplane water vapor emissions is equal to that from contrail formation. Unfortunately, these water vapor emissions may have a residence time of months in the stratosphere.

So guilt from my carbon and climate footprint aside, I’m looking forward to more insights into the role of water vapor in climate and climate change over the coming week.

Alicia Newton


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