Seminal Study Finds ‘Climate-Change Footprint’ In North America, ‘Continent With The Largest Increases in Disasters’

Climate­-driven changes are already evident over the last few decades for severe thunderstorms, for heavy precipitation and flash flood­ing, for hurricane activity, and for heatwave, drought and wild­-fire dynamics in parts of North America.”

So concludes Munich Re, a top reinsurer, in a major new study that, for the first time, links the rapid rise in North American extreme weather catastrophes to manmade climate change.

At the same time non-climatic events (earthquakes, volcanos, tsunamis) have hardly changed, as the figure shows.

Prof. Peter Höppe, who heads Munich Re’s Geo Risks Research unit, said:

“In all likelihood, we have to regard this finding as an initial climate-change footprint in our US loss data from the last four decades. Previously, there had not been such a strong chain of evidence. If the first effects of climate change are already perceptible, all alerts and measures against it have become even more pressing.”

The 274-page study, “Severe weather in North America” draws on “the most comprehensive natural catastrophe database worldwide,” though my favorite part is four words at the bottom of the back jacket:


This study builds on a September 2010 analysis by Munich Re, “Large number of weather extremes as strong indication of climate change,” which concluded:

… it would seem that the only plausible explanation for the rise in weather-related catastrophes is climate change. The view that weather extremes are more frequent and intense due to global warming coincides with the current state of scientific knowledge

At the time Höppe, explained to me what had persuaded him of the causal link:

For me the most convincing piece of evidence that global warming has been contributing already to more and more intense weather related natural catastrophes is the fact that while we find a steep increase in the number of loss relevant weather events (about tripling in the last 30 years) we only find a slight increase in geophysical (earthquake, volcano, tsunami) events, which should not be affected by global warming. If the whole trend we find in weather related disaster should be caused by reporting bias, or socio-demographic or economic developments we would expect to find it similarly for the geophysical events.

And that was before two years of off-the-charts extreme weather catastrophes, particularly in North America (see NOAA Chief 11/11: U.S. Record of a Dozen Billion-Dollar Weather Disasters in One Year Is “a Harbinger of Things to Come”).

It was also before multiple studies linking the surge in extreme weather to global warming, particularly in North America (see NOAA Bombshell: Warming-Driven Arctic Ice Loss Is Boosting Chance of Extreme U.S. Weather and links therein and below).

The new study finds:

Nowhere in the world is the rising number of natural catastrophes more evident than in North America. The study shows a nearly quintupled number of weather-related loss events in North America for the past three decades, compared with an increase factor of 4 in Asia, 2.5 in Africa, 2 in Europe and 1.5 in South America.

The study draws on a forthcoming journal article on how global warming is driving up “large-scale thunderstorm forcing”:

The results of the study indicate that climatic changes have driven up multi­year aver­ages of thunderstorm-­related normalized losses since 1970 and that anthropogenic climate change, most likely respon­sible for increasing levels of humidity over time, is fully con­sistent with this change.

Here’s a key figure on thunderstorm losses from the Munich Re study, “normalized to the current amount of destructible wealth exposed in the areas hit.” The “normalized annual overall thunderstorm losses displays a clear positive trend, even if the record­breaking year 2011 is ignored“:

No normalization is perfect. After all, while it’s certainly true that socio-­economic factors mainly drive up losses (and so must be accounted by some type of normalization scheme), it’s also true that there are factors typically not accounted for in these kind of analyses that would tend to reduce losses. For instance, building codes are better, and weather forecasting has improved, giving people more warnings of severe storms, and so on.

The scientific literature is also clear that we can expect an increase in thunderstorm intensity and destructiveness as greenhouse gas concentrations rise (see, for instance, here). And so the Munich Re study concludes:

Based on studies projecting the number of days with high thunderstorm poten­ tial to further increase with climate change, it can be expected that the number of large loss events will continue to rise. This translates into an imperative to take account of increasing losses over time in natural hazard risk management.

After all, we have warmed “only” about 1.4° Fahrenheit in the past century. We are poised to warm more than 5 times that this century. And that means — if we are foolish enough to stay anywhere near our current emissions path — we ain’t seen nothing yet.

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29 Responses to Seminal Study Finds ‘Climate-Change Footprint’ In North America, ‘Continent With The Largest Increases in Disasters’

  1. Mike Roddy says:

    The insurance industry is one of several that will be seriously harmed by climate change. Others include agriculture and traditional banking (as opposed to Wall Street). The American steel industry would benefit by a carbon tax, since our product is far less carbon intensive than China, the main competitor. Unfortunately, their reflexive right wing politics has kept this from happening.

    Why do these industries always get outgunned in Washington by sunset fossil fuel, timber, and utility industries?

  2. Chris Taylor says:

    Why haven’t I seen an article on Fee & Dividend as a solution:

    YouTube “Fee & Dividend”

    To me it’s the only solution, and Thinkprogress should be pushing it.

  3. Paul Klinkman says:

    One political question is, will a reinsurance company save money by working to end climate change?

    I say no. The reinsurance company will simply charge more money as a cost of their doing business. If they double their rates, every house, store and factory owner will pay through the nose, and every nation’s economy will slow a bit because of the high price of damage. Unfortunately, the reinsurance company won’t make any more or any less money in the long run.

    The only reason for an insurance company, or any company, to do the right thing for the world is because they are being watched for boorish, uncivilized behavior, and because millions of homeowners and small business owners will cancel their policies and never come back.

    We could use better organization of pro-environment consumers. Can the internet spread information more efficiently, more transparently? Which companies are acting like jerks, and which are good corporate citizens? If they’re all jerks in a certain field, how can we lure or startup a good company into that field to eat the dinosaurs’ lunches?

  4. Lionel A says:

    Meanwhile on another planet somewhere David Rose has another go for the vested interests which he serves through the Mail organ:

    The REALLY inconvenient truths about global warming. Last week we explosively revealed a 16-year ‘pause’ in rising temperatures – triggering a bitter debate. You decide what the real facts are…

    Sorry about the prolix headline, another sign that the Mail has lost what little they had.

  5. prokaryotes says:

    Potholer already debunking the claims from The Daily Mail

    Global warming has stopped? Again??

    No, sadly the Mail on Sunday has got it wrong… yet again. Here’s what’s behind the sensational news that global warming ended in 1997, and how it comes from misreporting, misquotes and omissions.

  6. Merrelyn Emery says:

    For the life of me I cannot see how all the changes in weight, pressure and temperature around the world is not going to affect geophysical events, particularly in sensitive areas such as the Rim of Fire. I believe the Royal Society said something similar a couple of years ago, ME

  7. Mulga Mumblebrain says:

    Murdoch’s local flag-ship, ‘The Australian’ ran a similar piece last week, but their ‘story’ asserted that there had been no warming over the last 2000 years, and that the Roman and Medieval warm periods were hotter than now. Its ‘Environment Editor’ who specialises in spreading the ‘wind turbines will kill you with mysterious diseases’ trope, brought us this gem. One of their previous ‘Environment Editors’ came straight from a stint as PR hack at the Minerals Council, the coal-miners’ lobby. Satire has died, outdone by Fox-reality.

  8. Joan Savage says:

    Munich Re’s graph would look even worse if not for weather satellites and fast telecommunications that give people a chance to run to shelter, evacuate, sandbag, and the like.

  9. Joan Savage says:

    That is to say, worse for implications of consequences.

    The Munich Re graph gives us something many had been looking for – an event-based graph, instead of an economic or human fatality measure.

  10. Jeff Poole says:

    That’s right Mulga – last I heard of that *ahem* ‘journalist’ he was heading up the renewable power peak body in Australia.

    Just crazy.

  11. Merrelyn Emery says:

    Thanks, ME

  12. Stephen says:

    It seems as though it will be the insurers who are likely to make the capitalist machine actually change course.

    Insurers will have to raise their premiums as their money making comes from paying out less than they receive and if that’s under threat they will charge. Of course, such premium hikes will increase costs for all business and homeowners thus reducing business profits and disposable consumer income – a double whammy ultimate horror for business. They will of course look elsewhere for companies charging lower premiums and initially they will find some, but ultimately, the premiums will continue to rise. Insurers are not charities and they will charge what they must to maintain profits. Eventually, the penny will drop and the government will actually realise that “Climate Change is bad for business”. Then we will see some action.

    Of course by that time it will be even later than now …

  13. Artful Dodger says:

    Chris, Fee-and-Dividend has been covered here:
    The larger issue is still putting a price on carbon.

  14. Spike says:

    The other factor I think is the impact of rising food prices and uninsured losses on business profits. With less disposable income resulting, much discretionary spending will come under pressure, and many businesses selling fripperies will find their sales declining.

  15. Big Bird says:

    Are we the leader of the free world? Yes! Let’s take the next step and fix this mess! It’s easy…
    Ask any climate scientist: Manmade carbon pollution is the cause of global warming.

  16. Lionel A says:


    William Ruddiman has been investigating the pre-industrial human impact on climate and the associated bumps and dips in CO2 and Methane emissions and temperatures with the MCO and LIA included as described in his Plows, Plagues, and Petroleum: How Humans Took Control of Climate.

    Further discussion in the October 2012 Open thread at Deltoid with input from John Mashey.


    I had already seen that Potholer debunk and worth a look as always but my reference was to a repeat article by Rose this last weekend which came after the Potholer debunk.

  17. Ozonator says:

    Thus, the extreme GOP is actually conserving the barter system in hopes of their mad world turning into blessed corporate plantations.

  18. Mike Roddy says:

    I think we have to be careful here, since the evidence is mixed. Better to stick with jarring weather events and projected disruptions to the water cycle.

  19. Stephen W says:

    “Are we the leader of the free world? Yes!”

    Err … excuse me?!

  20. Lionel A says:

    Of course, but Bill McGuire is careful to make clear from early on that events such as the Boxing Day Tsunami 2004 was not an event likely to have been caused by isostatic adjustment.

    What he does make clear is that such isostatic adjustments can, and have in the past, caused sudden large undersea mud slides which besides raising a Tsunami can further destabilise clathrate deposits.

  21. prokaryotes says:

    Yes. But i did not saw that particular video and i guess others as well. So it is always good to get all the data on a specific topic, to better understand the situation.

    Maybe someone curious about this claim from the Daily Mail, went to see now the video (22.000 vies so far) and found it interesting?

    If you only link to the denialist you basically repeat it, you even help to push it. Because this must be considered when linking to something, from looking at google search ranking algorithm, which ranks based on how many backlink’s one site has.

  22. prokaryotes says:

    A collection of the science about the connection between climate change and earthquake activity (geomorphological responses from ice melt, less pressure on former ice covered surfaces).


  23. Mulga Mumblebrain says:

    I thought it was the ‘Fee World’.

  24. Long distance power transmission, as in an eventual supergrid, is a key thing that must be implemented in order to move our energy economy off carbon. Though this is not a “sexy” issue, it somehow needs to be communicated…Joe Romm help us!

  25. mark E says:

    With greater certainty and evidence that an AWG signal is present in all major weather, I look forward to insurers refusing claims from carbon-polluters on grounds they financed their own ruin by funding climate denial. Maybe an “unclean hands” affirmative defense? At least it would make for some interesting discovery as the insurers attorneys probe the money trail via the discovery process.