MrPyrometer (MrPyro)

This is a re-post from Yale Climate Connections by Jeff Masters

A sequence of nine atmospheric rivers hammered California during a three-week period in January 2023, bringing over 700 landslides, power outages affecting more than 500,000 people, and heavy rains that triggered flooding and levee breaches. On a statewide basis, about 11 inches of rain fell; 20 deaths were blamed on the weather, with damages estimated at over $1 billion.

But the storm damages were a pale shadow of the havoc a true California megaflood would wreak.

The Golden State has a long history of cataclysmic floods, which have occurred about every 200 to 400 years — most recently in the Great Flood of 1861-62. And a future warmer climate will likely significantly increase the risk of even more extreme floods. In particular, a 2022 study found that, relative to a century ago, climate change has already doubled the risk of a present-day megastorm, and more than tripled the risk of a trillion-dollar megaflood of the type that could swamp the Central Valley. 

Given the increased risk, it is more likely than not that many of you reading this will see a California megaflood costing tens of billions in your lifetime.

This is the third part of a three-part series on California’s vulnerability to a megaflood. Part One examined the results of a 2011 study introducing the potential impacts of a scenario, known as “ARkStorm,” which would be a repeat of California’s Great Flood of 1861-62 — though the study did not take climate change into account. Part Two looked at how California is preparing its dams for future great floods. Here, in Part Three, we’ll look at the increasing future threat of a California megaflood in a warming climate.

This is a re-post from Yale Climate Connections

A lot can happen over the span of a decade and a half. And also not much, and certainly not enough.

That’s a sound-bite snapshot of the past 15 years for climate change and for this site since it first went live online. It’s been a great ride as founder and editor.

Thinking back to those halcyon days, much about climate change indeed has happened. Much of it, despite the loss of precious time in having not done nearly enough over those years to address the problem, for the better.

Better in the sense of broader and deeper public concern about and understanding, domestically and internationally, of the very real risks posed; about the nature of humans’ causing the warming; and about the real, albeit limited, “solutions” still available to us to help avoid the most serious consequences.

Think back: When we first launched, the term “global warming” was too often a late-night TV punch line for mocking Al Gore. Now, most of those same outlets are making authoritative documentaries and routinely addressing what they readily call the “climate crisis.”  Climate reporting staffs have been substantially expanded within many national newsrooms, print, broadcast, cable and online.

Better too in terms of the affordability of renewable energy alternatives relative to continued splurging on fossil fuel alternatives that yet today remain, by far, the dominant sources of energy for much of the planet’s now-eight-billion human inhabitants. And better also concerning the technological fixes available and under development and the growing acceptance of same. (The U.S. Department of Energy’s December 13 announcement of a potentially world-changing “second sun” fusion breakthrough is just the most recent example.)

Improvement in the overall “climate on the climate” derives in large part from hard-earned gains in public understanding, brought about by endless hours of tireless work and commitment by the global scientific community. And much of the credit for the progress stemming from their findings goes to federal support, notwithstanding its ebbs and flows, and to the charitable giving community and others who not only supported that work and, critically, spreading the word about it.

Listing of articles linked to on the Skeptical Science Facebook Page during the past week: Sun, August 14, 2022 through Sat, August 20, 2022.
The following articles sparked above average interest during the week (bolded articles are from SkS authors): The Arctic has warmed ‘nearly four times faster’ than the global average, Skeptical Science New Research for Week #33 2022, IPCC Explainer: Mitigation of Climate Change, and Halfway point in this year’s run of Denial101x – 6 more months to go!.
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