Is Recent Warming Volcanic and Not Anthropomorphic? We Don't Know
While many like to pretend there is a scientific consensus around global warming and anthropomorphic climate change, there never truly is.
While certain activists and political leaders like to make hay about the state of our climate and the perceived anthropomorphic climate change causing it, maybe that explanation isn’t all that it’s cracked up to be.
In an important thread on Twitter this morning, climate scientist Dr. Robert Rohde suggests that maybe the most recent short-term warming trends are caused by the volcanic eruption of the nearly monthlong Hunga Tonga–Hunga Haʻapai eruption.
Here is what Rhode had to say.
The Hunga Tonga–Hunga Haʻapai eruption was unusually water rich (& sulfur poor), injecting ~150 million tonnes of water into the stratosphere, increasing global upper atmosphere water mass by ~15%. As a powerful greenhouse gas, this water may have contributed to recent warming.
Water is much more abundant in the lower atmosphere but has difficulty crossing the tropopause (12-20 km) due to the very low temperatures. The Hunga Tonga–Hunga Haʻapai eruption burst through in early 2022 and has since spread through the upper atmosphere.
In the months immediately following the Hunga Tonga–Hunga Haʻapai eruption, the extra water was most concentrated in the Southern mid-latitudes, near the volcano, but has since spread to both hemispheres.
Why does it potentially matter? Despite its low concentration (parts per million), water vapor remains a significant infrared absorber in the upper atmosphere (reference plot prior to the HTHH eruption). Boosting upper atmosphere water vapor will impact the greenhouse effect.
How large is the impact of the Hunga Tonga–Hunga Haʻapai eruption on temperature? Personally, I remain unsure. Is this effect small compared to other normal variability, or is it more significant? There is a lot of nuance when it comes to radiative forcing in the stratosphere.Jenkins et al. estimated the global impact of Hunga Tonga–Hunga Haʻapai eruption at +0.035 C.
https://nature.com/articles/s41558-022-01568-2
But their technique was limited, and didn't really consider the spatial structure of the event or how it might alter weather patterns.
Might the unusually high levels of upper atmosphere water vapor have some relationship to recent regional extreme weather? For example, is the extremely large anomaly in an Antarctic sea ice somehow related to the water vapor plume high overhead? I don't know. Image: @ZLabe
Is the water vapor injection from the Hunga Tonga–Hunga Haʻapai eruption only adding a few hundredths of a degree to global temperatures (e.g. Jenkins et al.), or is it having more complicated effects we don't yet understand? I don't know, but I hope people are working on this.
It’s a fascinating idea to think about, that one recent volcano has ramped up the short-term greenhouse effect. This could be a direct cause of this summer’s heat in large swaths of the country.
But it also goes back to the fact that there is never a scientific consensus when it comes to anything in any scientific field. While many like to pretend there is a scientific consensus around global warming and anthropomorphic climate change, there never truly is. That is not to say that we should burn the forests and pollute the water, obviously, but it does mean that the most extreme measures to “save” us from global warming are done so in a manner that is not necessarily scientifically relevant.
Considering accurate weather records go back only to 1851, there’s a lot we just don’t know about past microclimates, weather, and even long-term global climate.
Something to think about as elected officials continue to push disastrous and unnecessary plans to change environmental standards.