Homo conflagrans

Someone recommended John Vaillant as a book-writing journalist, so I snagged Fire Weather: A True Story from a Hotter World (2023) off the shelf in Wexford Town library. The inspiration of the book and about 2/3rds of its content is the Fort McMurray wildfire which swept out of the surrounding forest and destroyed about 20% of the homes and emptied the city of ~88,000 people in a matter of hours. Nobody died! but damage was estimated at $10billion. In addition ~600,000 hectares of forest and muskeg were swept by a wall of flame - that's 3 medium sized Irish counties [KK + WX + WW] or the state of Delaware or an average département de la France.

Vaillant's thesis is that the McMurray fire and the other uncontainable conflagrations of recent years are a direct consequence of galloping climate change, in particular the way we have been spewing out greenhouse gases like CO₂ and CH₄ without heed or hindrance during my lifetime. Of course, my grandfather was pottering about Co Wexford in his own car for his own convenience in the 1940s so it's not all on me. But I've driven 100x further than my ancestor and I'm not dead yet. 

So here's a thing, known to all foresters and fire-fighters, but not obvious to all thinking people until it's e x p l a i n e d. "Crossover" occurs when the relative humidity in % is less than the temperature in °C; this makes conflagration much more likely - just a spark will do. We got a dehumidifier for the kitchen last November - hilariously named R2D2 R1DH. Our whole house, not just the kitchen has 500mm rubble-in-courses external walls. The windows used to weep and the walls developed a palette of fungal colours. We achieved a lowest ever RH of 52% at tea-time on the Spring Equinox after 3 days of cloudless sunshine. tbf, I opened the window and the front door for a warm draft to get from 55% to the shown [R] 52%. It has never gotten close to 52°C in Ireland. It's going to take another bomb to set our soggy house on fire. A weather station close to the 2018 Redding Fire recorded 44°C and 7% RH!

Here's another rule of thumb: firefighters need a water supply in gallons/min equivalent to the BTUs generated by the fire. A US gallon is about 4 lt and a BTU is about 1,000 Joules. That energy is enough to raise 250ml of water by 10°C. Now before the gas-grill goes on fire check to see how much water you can dribble out of your 12mm garden hose in a minute

Then again, then again, one of the tropes in Vaillant's tale is the Lucretius Effect, a cognitive bias where the biggest [whatever] you can imagine is the biggest example you've heard about . . . and a little bit more. But the temperatures of these MegaFires haven't happened since the end of the Permian 250million years ago. When the wall of flame stormed into residential sub-divisions of FtMcM they vaporized 200sq.m. million-dollar homes in 5 minutes - one big whooomph and there's nothing left but the [reinforced concrete] walls of the basement. Because it's a boom town and everyone was making silly money demand/supply drove up the cost and drove down the standards. Even the best homes in North America are thrun up from 4x2 studs and sheet-rock with vinyl siding and tar-paper shingles on the roof. To a regular fire that-all looks like so much fuel with convenient pockets of oxygen in each room. A garage full of cars and snomobiles with full tanks && propane tanks to service the BBQ grills && several fire-arms with boxes of ammo: that's just a source of pop-off shrapnel. If the owner and their bank pays a million dollars for a big-old shanty, lots of folks along the supply chain are laughing all the way to the same bank.

In Ireland one of the scandals of the Celtic Tiger was that developers and regulators conspired to cut corners with fire-safety - failing to separate each apartment from the next. But at least the structures were /are built of bricks not tar-paper.

Back to the book. The dust jacket says Vaillant writes for Nat.Geog. New |Yorker and The Atlantic. You can tell from "Steve's wife Carrie, who is tall and slender with wavy dark hair . . ."  and the numerous similar journo tics of providing irrelevant details to establish ?empathy? The style is pacy and engaging and reminds me of Mark Kurlansky and books about Salmon and Cod as bell-wethers for dramatic change in species diversity and abundance. I'm sure Vaillant and his editors thought and fought over the structure of Fire Weather: because he wanted to tell a gripping yarn on the streets of FtMcM but also flesh out the history of climate change and (climate change denialism).

But the transition whacked me into a confusion. p224/359 ends with ". . .It was the fire's third day inside Fort McMurray". And the next chapter begins with "The Middle Ages saw an slowly dawning awareness that there was something in the air . . ." followed by Priestley this then Tyndall that and Teller the other. Much as Ireland appreciates naming Tyndall for his atmospherics, we're still on the edge of our seats waiting to see what Day Four brings in NE Alberta.

"The climate system is an angry beast and we are poking it with sticks" Wally Broeker

Maybe read the book and spend sometime adjusting the content of your GoBag to include a reflective fire blanket and some tubes of Savlon. Always remembering Lucretius: the disaster which next requires a GoBag won't be stranger than we imagine but stranger than we can imagine. 

*R1DH aka Our one de-hum.