28 Comments
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Keith Muir's avatar

Is it not possible/likely that climate change plays some part in this? According to The Epidemiology of Extreme Weather Events ( 1969-2018), "Regression analysis revealed strong evidence (R2 = 0.88) that the annual incidence of EWE disasters is increasing worldwide"

According to Swiss Re, average economic losses from natural disasters averaged $267bn from 2015 to 2023, hit $327bn in 2025 and then fell to $220bn in 2025.

I live on NZ's North Island, and several areas including my own, recorded record 24 hour rainfall last week, causing huge devastation and sadly, loss of life. Now, we are a small land mass surrounded by sea and appears to be warming. Again, the question surely is not whether was climate change on its own, but to what extent did it contribute to it. Was it negligible-say 2/3%- or significant, 10% or more?

I don't have the answer, but it seems likely to me that climate change has played a part. We know that warmer can hold more moisture-some 7% for each 1 degree-and what goes up must come down.

As Mike Hulme puts it, climate change isn't everything, but conversely, that means it is something, leaving the big question, just how much?

Dean's avatar

What goes up must come down. I wonder how the Hunga Tonga eruption plays into that extreme rainfall.

Keith Muir's avatar

Dean,

I asked and received a reply almost immediately. Here is part of it: " You ask an interesting question, but the short answer is no. Hunga Tonga's eruption did put an extraordinary amount of water vapour into the air, but most of it went into the stratosphere, above the level of our 'weather'. The water in the stratosphere would have contributed to global warming as it is a strong greenhouse gas, but it would not have directly interacted with weather systems.

The part of the water vapour plume that stayed in the troposphere(where we and the weather are) probably did contribute to rainfall events shortly after the eruption. However, the typical lifetime in the atmosphere of water vapour is around 9 days, while the eruption was 4 years ago.

So I'd rule out any eruption effect on the recent floods in your region".

Quite separately, I have a much more detailed look at the recent extreme rainfall which considers factors such as the Southern Annual Mode(SAM), the La Nina phase of ENSO and warming oceans. We are a small landmass surrounded by water.

Keith Muir's avatar

A good question and I think the answer is yes. I understand that a vast amount of water vapor was ejected into the atmosphere and will take years to dissipate. What I don't know is to what extent last week's rainfall here was increased, but I would be very interested to know more.

As you can imagine, some people have just assumed/insisted that it's all down to global warming and that's far too simplistic. I am on good email terms with one of our leading climate scientists, so might put this to him.

Rick Love's avatar

Hi Keith: It seems the answer may be that atmospheric physics indicates a rise in GHGs impacts weather, but the extent to which that is true is not quantifiable. Somewhat akin to the Amazonian butterfly effect and also more pertinent when you are sitting in the middle of a record 24 hour rainfall. When asked, the Google machine offers this answer "Yes, the annual total number of record-breaking 24-hour rainfall events has significantly increased globally, particularly over the last three decades and continuing through the last ten years (2015–2025). This trend, driven by climate change, has seen a 40% increase in daily maximum rainfall records from 2016 to 2024." I'd be curious if Roger thinks the "driven by climate change" is defensible.

Roger Pielke Jr.'s avatar

Climate change, by definition, is not detectable over 8 years. That said, there is solid evidence that the hydrological cycle has intensified over many decades and that has been attributed to GHGs from human activities.

Rick Love's avatar

Thanks Roger. I'd forgotten the 8 year perspective required.

Keith Muir's avatar

I will be interested to see his reply.

Roger Pielke Jr.'s avatar

These are perfectly fair questions

A few thoughts

1. Climate change doesn’t cause weather

2. To detect a change in the statistics of weather events requires a long time series of observations

3. The effects of GHGs on weather trends is not expected to be detectable for most phenomena in 2025 (not all)

4. Don’t look for weather trends in economic data

Jeff Walther's avatar

If the value of insured properties increased and caused the increase in losses, shouldn't the income from writing policies also have increased? In other words, it simply sounds like insurance companies have expanded the amount of business they're doing.

I notice none of those graphs include a trend of collected premiums along with their losses.

Lee Nicholson's avatar

The ability of some people to constantly discount "normalization" and pre-anthropogenic trends in order to panic the rest of us is so disappointing. GDP. Population. Life expectancy. Inflation. Assets in harm's way. Pre-industrial seal-level trends. None of these seem to matter to them.

C. Richards's avatar

Roger: requesting your analysis of the rising ocean levels component of climate change scenarios. I live in the San Francisco Bay Area, with lots of shoreline exposures. There is a steady drumbeat about rising sea levels and the potential for financial and human catastrophes. Recent king tides and storm swells were given second billing to rising oceans for coastal flooding in all the usual places in the region. Would love to hear more about actual trending measurements vs. worst case models. Or, you or a reader might point me toward a good resource. Thank you for your article. Always rigorous and timely.

DBC's avatar

The oceans used to be 400 feet lower curing the ice age(s).

Read somewhere that since 1900, ocean level is up 8". Sounds plausible, in a warming period.

Here's a 500 million year study... we're warming within a cool period. The chart is self explanatory... More warm - no polar ice caps periods than cold periods with ice caps.

The chart also confirms, that warm periods follow cold periods - and we're in a sweet spot right now.

https://www.science.org/content/article/500-million-year-survey-earths-climate-reveals-dire-warning-humanity

David Young's avatar

Cliff Mass has a recent blog post where he talks about how climate change is a manageable problem. He talks about sea level and shows the tide gage record for Seattle. Over the last 140 years sea level has been rising at a remarkably constant rate and there is no hint of acceleration. In fact the main component of sea level rise or fall is coastline subsidence or rise. In the far North the land is still rebounding from the last ice age and sea level is falling. In Louisiana, where the land is subsiding, sea level is rising faster than the global average. Subsidence is due to oil and gas extraction and the fact that the levees prevent the yearly deposition of sediment that has been happening for tens of thousands of years before Western technology came into play.

Douglass Allen's avatar

So.....global Weather Catastrophe Losses trending downward a little. Weather related event mortality trending down a lot. What's not to like?

Steve Ballenger's avatar

So it was Bidenflation not climate change. Who knew!

Sorry, I couldn’t resist. 🙂

J. EICH's avatar

Most people won't look at figures like these. Instead they'll view videos of wild fires and say, "Climate change did that." In a recent report on the Palisades fire, it was revealed that the initial blaze that led to devastation was never verified completely out because of concerns about driving machinery on ecologically fragile terrain. If true it seems man's stupidity is a greater threat than rain, wind and fire.

environMENTAL's avatar

Whether that turns out to be true or not, man’s stupidity is definitely the greater threat.

Barry Butterfield's avatar

Nicely done, sir. Thank you.

"Climate change presses on" = "Dog might catch tail"

Donald Rapp's avatar

Roger: You have amply shown that hurricanes, tornados, etc. and more generally damage from extreme weather are no more prevalent today than in the recent past when account is taken for inflation and changes in demographics. But I seem to recall that you concluded that heat waves have increased and the rate of sea level rise may have accelerated. I haven't seen you comment on these in quite a while and I wonder if it is now appropriate for you to do so?

David Young's avatar

Cliff Mass has a very good blog post last week on how climate change is a manageable problem. There is a section on sea level rise. He has a graph of tide gage data from Seattle showing an absolutely linear rise over the last 140 years with no hint at acceleration. The main component of relative sea level is the land rising (as in the far North) or subsiding as in Louisiana where massive oil and gas withdrawals result in the coastline sinking.

Roger Pielke Jr.'s avatar

Yes good idea — I had written on heat waves, but it has been a while

https://open.substack.com/pub/rogerpielkejr/p/what-the-media-wont-tell-you-about-9f9

I have drafts of some posts on SLR that I should finalize and post

Many interesting issues there 👍

Rob F's avatar

This all tracks, and it feels like the quiet part that keeps getting skipped is COVID economics, not climate. Turbo-charged asset prices during COVID, then layered on construction inflation that made every replacement costs enormous. Of course “losses” look bigger, we turned every ranch house into a million-dollar property.

Then came higher interest rates, which didn’t just cool demand, they froze starter housing in place. People aren’t moving, they’re piling capital into existing structures. That concentrates exposure, raises insured values, and makes every marginal weather event look more “catastrophic” on paper, even if the weather itself disagrees.

So yeah, losses up, reinsurers still printing money, and headlines still yelling “CLIMATE PRESSURE.”

Turns out hurricanes don’t price houses, humans do.

PharmHand's avatar

Scholars at the Center for Mark Twain Studies of Elmira College have found no substantive evidence supporting the ascription to Mark Twain.1

The observation has been attributed to several other prominent humorists including: Josh Billings (pseudonym of Henry Wheeler Shaw), Artemus Ward (pseudonym of Charles Farrar Browne), Kin Hubbard (pen name of Frank McKinney Hubbard), and Will Rogers. Yet, it is unlikely then any of them said it. The creator remains anonymous based on current evidence.

Rob F's avatar

I stand corrected. Must have gotten Twain-washed ( if that’s a thing) my apologies

PharmHand's avatar

“Continuous improvement is better than delayed perfection.”

Mark Twain

🤓