The Kingdome of Heat Domes
The Kingdome of Heat Domes
The language of Climate Change and When it was Really Hot
Heat dome—how many of us had heard this term prior to a couple of weeks ago? It seems that the phrase simply popped into our collective conscience like a bad song we couldn’t shake: we wanted it to go away but the more we dwelt on it the more entrenched it became. And, it did sort of appear out of the blue. I recently did a key word search on “heat dome” in a database of newspapers, including the New York Times, Washington Post, and Los Angeles Times, and the upward trend was clear. (A search of the Seattle Times and Seattle P-I databases is basically the same though the increase in use of heat dome doesn’t appear until the end of the 2010s.)
Heat dome is not alone. Consider terms such as polar vortex, bomb cyclone, derecho, flash drought, and warm blob. All were previously used by meteorologists, who like other scientists, have precise words that allow them to communicate more clearly with each other, but each is new to the general public, and each has recently had its moment in the spotlight. I suspect that we will encounter each again because their appearance is not random. It is tied to climate change.
An important component of climate change is that weather that is an extreme version of a potentially impactful event will become more intense and/or broader and/or longer lasting. What this means is that although weather isn’t climate and that one can’t blame each and every weather weirding on climate change, the trend is clear: We are going to see and experience more and more extremes of historic proportions. And, with these changes come new terms for all of us to learn.
As a writer watching this evolution of the language of climate change, I feel sort of like a biologist, watching adaptation in real time. I wonder which words will survive and seed our lingua franca and which will disappear, like the glaciers now melting in the increasing heat. (I worry we could loose one of region’s few weather-specific terms—sunbreak—if our skies turn too sunny. Yuck! ) I hope though that perhaps we can learn from events like the heat dome and realize we need to get our shit together and do something now. If not, stay tuned for the next new term to learn.
An article in the Washington Post called the heat dome a once in a 1,000 year event. I would like to make an even larger claim. Our recent three-day run of 100-degree-plus days may be the first on a geological timescale. We know, for example, from pollen data, that the planet warmed following the retreat of the Puget lobe glacier about 16,000 years ago (basically it was cooler and drier than at present) and, that by about 5,000 years ago, we had reached our modern, pre-climate change climate in Puget Sound. These climatic conditions led to the emergence, spread, and rise of our Douglas fir/western red cedar/western hemlock ecosystem. Based on climate records preserved in ice cores, it is doubtful, though possible, that temperatures of “extremes of historic proportions,” as one meteorologist described the heat dome to me, have ever occurred in the time since the rise of the cedar trees.
I would further argue that western Washington has possibly not had temperatures like the recent ones for the past 50 million years, during what is known as the Early Eocene Climatic Optimum (EEOC). (There was also a warm period about 15-17 million years ago but there is less good evidence about it in the PNW.) Leaf fossil analyses from a sandstone layer near Bellingham known as the Chuckanut Formation show that the mean annual temperature in the EEOC was 62 to 68°F. As a comparison, Bellingham’s modern average is 49°F.
During that long ago era of unprecedented temperatures, the sub-tropical to tropical ecosystem now preserved in the Chuckanut rocks included large tropical palms, tree ferns, and swamp cypress. Further evidence for the EEOC comes from marine microfossils called foraminifera, which show very warm ocean water from that period. Both the plant and animal lines of evidence cannot show a single day of temperature but both do indicate temperatures well above our modern norms, which could easily translate to hot days on the order experienced this past week.
And a few weather tidbits. Weather records have been kept in Seattle since 1891. From then until 1972, the instruments were at the Federal Building in downtown. Since 1945, Sea-Tac Airport has been the official weather station. Statistically our driest days of the year are July 30 and August 4. The three days with highest average temperature— 77 degrees—at the airport are July 30 and 31 and August 1. At the Federal Building, the high days are July 21 to 28, with the same average. November 19 is the wettest day, with rain recorded on 79 out of 105 years.
I would like to thank all who ordered copies of Homewaters from me after the excerpt appeared in the Seattle Times. I ended up running out but now have fresh stock available to order.