The Hawaii fires...

[Externet]

Hi. 

In the news, a supposedly expert opinion on that Hawaii fire said the hotter weather promotes more evaporation yielding more ready-to-burn fuel.  (Makes some sense) ,   Is that a too simplistic point of view ?  More evaporation can mean more precipitation somewhere else,  does it ?   Is all of this climate changing too guessy ?   -The cause of the fire if was electrical sparks or not was left out of the discussion-

Are coincidental events as hurricane wind, drought, season, temperature... more influencing factors than anything else in the disaster ?

[iNow]

Droughts are worse and wild fires are extinguished to protect dwellings. This creates more tinder and sparks from human activities and power lines love jumping into kindling like that. 

[TheVat]

More powerful tropical cyclones (AKA hurricanes) are related to warming, too.  The high winds on Maui were from Dora, which made the fires much worse.  Global warming increases atmospheric energy in various ways that can all contribute to more destructive wildfires.  

Another (non GW) factor in the huge destruction of homes is that the climate has allowed rather loose observance of building codes, especially older homes.  We have friends in Hawaii who have mentioned that many older houses were built with basically a wooden shell with siding nailed on.  No sheetrock on the interior.  No wall cavity (that 14.5 inch space between studs) with fire resistant insulation.  Jalousie windows that allow maximum ventilation and don't close enough to seal the interior.   Such houses get "grandfathered in" and aren't later brought up to current code.   

[thidmir]

While these reports on wildfires don't seem alarming and it isn't necessarily tied to climate change, one has to keep in mind that the consequences of climate change can accelerate so it is important to keep track of what events are due to climate change and what not. 

 

Santosh Gupta

[swansont]

It may be difficult to tie a single event to climate change, much like you can’t tell for sure that seatbelts saved a life in certain accidents. But it becomes clearer when you look at the statistics of all the events.

[OldChemE]

7 hours ago, swansont said:

It may be difficult to tie a single event to climate change, much like you can’t tell for sure that seatbelts saved a life in certain accidents. But it becomes clearer when you look at the statistics of all the events.

15 years ago (previous home, different State) one of my regular golfing buddies was a climate scientist who educated me some on what was going to happen.  His comments were very much like the above.   To paraphrase: 'We are putting more energy into the atmosphere and the oceans.  Its like heating a pan of water to a boil-- lots of exciting things are going to happen, due to the energy input, but we cannot yet predict, exactly, what they will be.'

[Ken Fabian]

On 8/20/2023 at 12:10 PM, Externet said:

Hi. 

In the news, a supposedly expert opinion on that Hawaii fire said the hotter weather promotes more evaporation yielding more ready-to-burn fuel.  (Makes some sense) ,   Is that a too simplistic point of view ?  More evaporation can mean more precipitation somewhere else,  does it ?   Is all of this climate changing too guessy ?   -The cause of the fire if was electrical sparks or not was left out of the discussion-

Are coincidental events as hurricane wind, drought, season, temperature... more influencing factors than anything else in the disaster ?

There are a whole lot of factors. Here in Australia we are facing a potentially very dangerous fire season and the factors are feeling all too present to me. I've probably done equivalent to a day each week towards prevention and preparation over the past 6 months, removing undergrowth, piling and burning the cuttings, burning small areas of thick, dry grass, am partway through adding a sprinkler system, another water tank ordered. It is costing money and time in significant amounts. And if conditions turn bad enough we could still be forced to evacuate and no-one will be there to start the pump! So it will only help for less than worst case scenarios. We are not in serious drought yet but 3 wet la nina years saw exceptional regrowth that in large areas (including around our home) "ladders" to the forest canopy ie fires will readily reach forest canopies.

There is "proximate cause" - what lights a fire - and there is the flammability - what makes it susceptible. Being hotter doesn't light fires but it makes it more flammable. I don't know if dry lightning storms are made more likely in places by global warming - it seems possible; our most recent very bad fire affecting this area started from lightning. When it is hot and dry and dead vegetation is approaching zero moisture content almost any spark will start a fire. Where there are people there won't be shortages of things that can start fires. I am actually astonished that we can get through any hot dry fire seasons without being burned out, yet very often we do.

Beware the rhetoric of those who like to confuse and distract by conflating what makes it more susceptible and what actually starts a fire. I suggest waiting until post fire investigations are complete before assigning blame; we had a lot of fevered media excitement over alleged arson in 2019 but investigations showed very few cases of arson. Negligence, bad judgement and stupidity did rear their heads, yes, and "back burns" (attempts to contain a fire by burning back into it, ahead of the fire front) that didn't work as planned, with electrical faults and dry lightning storms major proximate causes. I recall a volunteer firefighter accused - even arrested - for a fire that saw multiple deaths; the fire was observe to start very near his home for no apparent reason. Proper investigation later showed he had been truthful all along and the fire started from a power line coming down further down the road; it landed on top of a wire fence strung on wooden posts. It shorted and sparked close to the poor man's house rather than where the line came down.

A popular "blame the same activists who go on about warming" meme we saw was "environmental regulation prevents cool weather burning off". In my experience it hasn't been environmental concerns, it has been public safety ones that have been the primary reason for reluctance to do burning off. An influx of people onto smaller primarily residential rural holdings who lack the knowhow and equipment has seen (not surprising) a reluctance to burn off surrounding bush, especially larger areas. They are more likely to have environmentalist sympathies (and get labeled for it) but safety and potential liability for the fire that gets away seems a bigger impediment than ideology; I am not aware of environmentalist groups with policies of opposing the use of fire as a management tool, even if they want it done well. Also no surprise that fire authorities will call a stop to burning off when conditions get more dangerous, especially when so many fire permit holders are inexperienced and poorly equipped.

But we are also seeing narrowing windows of opportunity to do so safely because of warmer conditions. Forest management for the very large areas tend to be inadequately funded as well; a lot more crews and equipment are needed to take full advantage of suitable weather conditions when we get them.

We have had record warm Winter temperatures across much of Australia and that makes reduced opportunities;  traditional practices quietly relied on cool overnight temperatures laying down natural fire retardant (dew) so fires lit the previous afternoon could be relied on to largely self-extinguish. With warmer winters and nights those conditions occur less frequently, across smaller areas. Increasingly we need more labour, equipment and effort to do the same things safely. Our lightning-started 2019 bushfire - started and out of control at the end of Winter - burned for more than 6 weeks in rough and inaccessible country before it came around us. The prospect of 3 C of warming - which will give above 4C around here - is a terrifying prospect, not only for hotter, more dangerous fires at the height of the fire season but shrinking opportunities to reduce fuel loads by burning off in the cool season.

 

Edited September 2, 2023 by Ken Fabian

[mistermack]

I blame the grass skirts and barbecues.  

[StringJunky]

Maybe they will think about about insisting on fireproof roof coverings, rather than 'fire resistant' ones that will eventually auto-ignite given a high enough temperature. Apparently, flaming material was carried in the wind and deposited on these roofs... you know what happens next. This house has a metal roof and the owners cleared brush around it just as a tidying up exercise, not for fire prevention.

[Ken Fabian]

Even dedicated fireproofed homes are at grave risk when the fires are fierce enough.  Most of the homes lost in Australian bushfires had metal roofs. I recall an account of a house that appeared to have survived only to burn a few days later from a roof screw connected to a hidden timber that had started smouldering undetected - the heat on the roof and the screws were enough to have done that. Even where homes are built of non-flammable materials, they get filled with them.

Rainwater gutters are a major fuel trap - we have mesh over our gutters but fine leaf matter does still accumulate; if it catches fire it can get under the roof. Recommended to plug the downpipes and fill the gutters with water ahead of a fire.

Flywire mesh and draft proofing helps - fine mesh won't let flames pass through and drafts are another way extreme hot air and flames get into the structure. Water sprinklers are a big help but even that has limits, especially with limited water supply - town water supplies can struggle too, when whole districts have hoses and sprinklers running; I've chased ember spot fires with a hose that was down to a trickle whilst neighbors were all doing the same.

Next step after all the fireproofing and preparation is having fire bunkers - often concrete water tanks remade for the purpose. That may be another step for us to take here.

[mistermack]

Trying to think what else could save a building, my first idea would be a fairly thin fiberglass matting that could be draped over the roof, and down the walls using long poles. Then have a few pumps jet a fine spray of water onto the matting in the event of a fire, till the risk had gone. You would need a storage tank full of water, ready and waiting. The wet matting should stop the flames and heat for long enough for the fire to pass. 

[Chhavi421]

Yes, the expert opinion provided is too simplistic. Evaporation does lead to more precipitation elsewhere, so the expert should have taken that into consideration. Additionally, climate change is an influencing factor in disasters, and it should be considered in this discussion. Other influential factors include hurricane wind, drought, season, temperature. It is difficult to tell the exact cause of the fire without taking into account all influencing factors.

[Ken Fabian]

9 hours ago, Chhavi421 said:

Evaporation does lead to more precipitation elsewhere, so the expert should have taken that into consideration.

High evaporation rates during hot and dry conditions is mostly potential for evaporation; as the moisture content diminishes from soil and (dead and dying) vegetation the actual evaporation rate does too.

It doesn't make any difference to the flammability of the parts of the world experiencing hot, dry conditions at increased average temperatures; the evaporation during droughts doesn't deliver any extra rainfall where the droughts are occurring - warmer temperatures actually mean the air has to have a higher water vapor content to reach saturation (for precipitation to occur), ie it makes rain less likely. Having more rain in places that already have high rainfall - because warmer air in damp places takes up more water vapor and combines to increase rainfall - doesn't make damp places that have very low fire risks less flammable.

 

 

Edited September 8, 2023 by Ken Fabian