
Atmospheric Scientist on the CA Fires - js2
https://www.nytimes.com/2019/10/28/us/california-fires-getty-kincade-tick-sonoma-county.html
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js2
I've submitted this article for the section at the end which is titled "The
best scientific answer to what’s going on …"

 _Adam Sobel, an atmospheric scientist and director of the Initiative on
Extreme Weather and Climate at Columbia University, gives an explanation:_

This increasingly awful fall fire season follows hard on the previous two, in
2017 and 2018, both of which were worse than any in recent memory. Some of the
same regions, and people, are being affected repeatedly in quick succession.
Psychic trauma is surely compounded significantly for these residents, not to
mention the firefighters on the front lines.

How should California residents think about the future, when the present is,
suddenly and persistently, not only far outside their prior experience, but
also, in its scale and velocity at least, beyond what science had predicted?

It’s an increasingly common experience, occurring with other kinds of events
as well. Heavy rain events are becoming heavier around the world, but known
climate trends can’t explain the repeated 500-or-more-year floods that Houston
has seen in the last few years.

In the case of the increasingly frequent wildfire disasters in California, I
argued the other day that they have multiple causes: poor maintenance by PG&E,
expanded human settlement at the margins of fire-prone woodlands, and global
warming. But I don’t think any of them explains either the suddenness or the
persistence of the change that Californians have experienced in the last three
years.

When it comes to the weather, and the climate, my views here are strongly
informed by discussions with my colleague Park Williams, an expert on wildfire
and climate whose research is directly relevant. That research shows that the
area burned by fires each year in the summer months has increased drastically,
and this is consistent with the influence expected from global warming.

But, as explained by Mr. Park in his recent research article, and in The Times
on Friday, the headline-making fires of the last three years have all occurred
in fall. In that season, temperature has a role, but other factors are likely
to be more important — first and foremost, the dry Diablo and Santa Ana winds.

Those are mainly fall and winter phenomena, and clearly critical factors in
the recent and current fires. But these winds are actually projected to occur
less frequently as the climate warms (with no clear trend yet apparent in the
observations). So the fires may be attributable to weather, but the most
critical aspect of the weather isn’t directly attributable to human activity —
nor, as far as I can tell, to any other, identifiable, larger cause. So what
is going on?

My guess is that the best scientific answer goes something like this. The
sparking might have gotten worse over time. But more important, in the last
three years, it has encountered the hot, dry downslope winds markedly more
often. And global warming is probably making those winds a little hotter, but
the wind events themselves, the most important proximate causes, may well be
only explainable, ultimately, as “natural variability.” That means they are
inherently unpredictable. Bad luck, in other words. If this is true, it would
suggest a decent chance that next year shouldn’t be as bad.

Or maybe the causes are in principle knowable, but current science just
doesn’t know them. Maybe climate change is proceeding more rapidly and
dangerously than we understand.

But it’s still good to understand what the limits of our knowledge are. That
should keep us humble about our place on the earth.

