Contemporary climatic analogs for 540 North American urban areas in the late 21st century

I guess sometimes you just have to throw the officially acknowledged lack of regional skill for GCM’s out the window~ctm

From Nature Communications

Abstract

A major challenge in articulating human dimensions of climate change lies in translating global climate forecasts into impact assessments that are intuitive to the public. Climate-analog mapping involves matching the expected future climate at a location (e.g., a person’s city of residence) with current climate of another, potentially familiar, location – thereby providing a more relatable, place-based assessment of climate change. For 540 North American urban areas, we used climate-analog mapping to identify the location that has a contemporary climate most similar to each urban area’s expected 2080’s climate. We show that climate of most urban areas will shift considerably and become either more akin to contemporary climates hundreds of kilometers away and mainly to the south or will have no modern equivalent. Combined with an interactive web application, we provide an intuitive means of raising public awareness of the implications of climate change for 250 million urban residents.

Introduction

Within the lifetime of children living today, the climate of many regions is projected to change from the familiar to conditions unlike those experienced in the same place by their parents, grandparents, or perhaps any generation in millenia1,2. While scientists share great concern for the expected severe impacts of climate change, the same is not necessarily true of the general public3,4,5. At the same time, decision makers have not formalized climate adaptation plans for a large proportion of major cities6, and existing efforts often are considered insufficient to avoid social, environmental, and economic consequences of climate change7.

Disconnects between the potential threats of climate change and societal action arise from multiple factors4,5,8, but changing how people perceive and conceptualize climate change is considered key to improving public engagement4,5,8. For example, it is difficult for people to identify with the abstract, remote, descriptive predictions of future climate used by scientists (e.g., a 3 °C increase in mean global temperature). Translating and communicating these abstract predictions in terms of present-day, local, and concrete personal experiences may help overcome some barriers to public recognition of the risks (and opportunities) of climate change9,10. Given that most humans reside in urban areas and urban populations are considered highly sensitive to climate change11, it is important to assess what climate change could mean for urban areas and to communicate the magnitude and uncertainty of these expected changes in intuitive ways.

Climate-analog mapping is a statistical technique that quantifies the similarity of a location’s climate relative to the climate of another place and/or time12,13,14,15. When considered in the context of assessing and communicating exposure to future climate change, climate-analog mapping can be viewed as a form of forecasting by analogy16,17 that translates the descriptive and abstract (i.e., scientific forecasts of future climate) into the familiar (i.e., present-day climate of a known location). Veloz et al.18 used climate-analog mapping to find contemporary climatic analogs for projected future climates for the U.S. state of Wisconsin, while Rohat et al.19 used similar methods to quantify and communicate the implications of climate change for 90 European cities. Climate-analog mapping is gaining popularity as a means to communicate climate change impacts20,21, and more robust methods for measuring climatic similarity between places and times have been recently developed22.

Here we use climate-analog mapping and an interactive web application (available at https://tinyurl.com/urbanclimate) to characterize and communicate how climate change may impact the lives of a large portion of the populations of the United States and Canada. Collectively, the 540 urban areas we analyze in this study include approximately 250 million inhabitants, including >75% of the population of the United States and >50% of the population of Canada. For each urban area, we mapped the similarity between that city’s future climate expected by the 2080s (mean of the period 2070–2099)23 and contemporary climate (representative of mean conditions for 1960–1990)24 in the western hemisphere north of the equator (Supplementary Figure 1). We identified climatic analogs using sigma dissimilarity22, a statistical measure that accounts for correlations between climate variables, incorporates historical interannual climatic variability (ICV), and converts multidimensional climatic distances to percentiles of a probability distribution of these distances. A sigma dissimilarity equal to 0 (i.e., 0σ) would indicate identical climates, or a perfect analog. We considered values of ≤2σ between an urban area’s future climate and its most similar contemporary climate to be a representative analog. Values >4σ represent extreme differences between future climate and contemporary climate within the study domain, which we interpret as novel future climatic conditions22 and a poor analog. In this sense, sigma dissimilarity serves as both an indicator of climate novelty and a measure of the strength of analogy between an urban area’s future climate and its best contemporary climate match.

We calculated sigma dissimilarity using minimum and maximum temperature and total precipitation for the four climatological seasons (12 climate variables total). For 2080’s climate, we selected two emission trajectories or Representative Concentration Pathways (RCPs)25, unmitigated emissions (RCP8.5) and a mitigation scenario (RCP4.5)26, and 27 different earth system models (ESMs), for a total of 2 RCPs × 27 ESMs = 54 future climate scenarios (Supplementary Table 1). Here we emphasize results for the ensemble means of 2080’s climate calculated by averaging across the 27 climate projections for each RCP.

For each future climate scenario, we calculated sigma dissimilarity between each urban area’s future climate and every contemporary climate pixel in the study domain. We mapped the resulting sigma values to create a climate similarity surface and identified the pixel with the minimum sigma dissimilarity. This pixel represents the best contemporary climatic analog to 2080’s climate for that urban area and climate scenario, again noting that values >2σ increasingly characterize novel climates rather than representative analogs.

We find that if emissions continue to rise throughout the 21st century, climate of North American urban areas will become, on average, most like the contemporary climate of locations 850 km away and mainly to the south, with the distance, direction, and degree of similarity to the best analog varying by region and assumptions regarding future climate. For many urban areas, we found substantial differences between future climate and the best contemporary climatic analog, underscoring that by the 2080s many cities could experience novel climates with no modern equivalent in the study domain. In addition to the summaries we report here, we visualize climate analogs for all 540 urban areas and 54 future climate scenarios using an interactive web-based application (available at https://tinyurl.com/urbanclimate) that provides a means to communicate abstract forecasts of future climate in terms that are more locally relevant to the nearly 250 million people who call these urban areas home.

Read the full article here.

HT/ Clyde Spencer

41 thoughts on “Contemporary climatic analogs for 540 North American urban areas in the late 21st century

  1. OMG the time and effort wasted on CC and the way the liberals wring their hands about forecasting the future dystopia they foresee, it is all so laughable. I am glad there is C02 getting back in to the biosphere, it will be good for things in a good many ways.

    • Climate-analog mapping is a statistical technique …

      Statistical manipulations are NOT science. Get back to me when you have some actual SCIENCE to report. Meanwhile enjoy your statistical circle jerk … and made-up statistics at that … wherein you tell your circle jerk mates that 4 inches is really a big 10 inch.

  2. Oh goody! I hope it warms up enough so that the analogue to my town is Tampa, Florida. I’m getting tired of paying good money to spend winters in the Tampa Bay area.

    Alas, I think the analogue will be Louisville, Kentucky. Not good enough by a long shot.

    P.S. I think this one is going to backfire, particularly with those in more Northern climes. “We’re gonna be like Atlanta? Shazaam! Bring it on!”

    • I don’t know…..you have to be good to convince people warmer is worse
      …and a complete idiot to fall for it

  3. I believe a chimp throwing darts at a climate prediction board has an even chance as the climate change seers of the future of being correct.

  4. UHI causes increases in temperature. UHI occurs mostly in urban and city areas. All over the World people are deserting rural areas with low to no UHI and flooding into UHI modified environments in cities. People vote with their feet. They will happily put up with UHI for the benefits of Urbanisation.

  5. Like our grandparents didn’t see climate change…our parents didn’t…..we didn’t

    …so of course it’s going to be a shock to the kids today

    /snark

    • Then it would obviously be the fault of skeptics. Somehow.

      It will NEVER be alarmists fault. EVER.

      As I point out to them: how can you be sure that you are eliminating ONLY the man-made climate change? Even the best “science” has it at, what 60/40 split. So of one degree changed (up OR down), all the hundreds of billions of dollars spent on unicorn farts should only fix .6 of that degree.

      Don’t think about touching that .4. That’s messing with nature. Which is ok only when you discuss gender with them…

    • If it got colder the polar bears would feed in Winnipeg’s dump (whoops-landfill) instead of Churchill’s dump. I checked out Winnipeg. The reduced emissions scenario landed in North St Paul MN. The business as usual model ended up in a southern suburb of the Twin Cities! The temp difference was 2.7C vs 3.0C. Hardly worth spending a fortune on that. Other best fits amoung the 27 models ranged from the Quad Cities on the Mississippi River, to Ottawa ON, to two towns near the MB/ND border (less than 100km). So much for settled science. This is a joke.

  6. A) Models with zero predictive skill
    B) Gross assumptions based on worst case absurdities
    C) Fairytale fantasies based on pure silliness
    D) Waste of time, waste of funds, researchers better qualified for sanitation pickup.

    What can go wrong?
    What is certain is that nothing will go right.

  7. The temperature change now between the high and low of many ordinary summer days in many places, and many winter days too, is an order of magnitude greater than the change they predict by 2080 – and excuuuse me if I am skeptical since it’s all based on models that have shown NO predictive accuracy…

  8. Most of those advocating for alterations to our economies and societies because of expected changes to our climate are so ignorant of the actual science that some way must be found to relate the predicted changes. This would be a useful tool if not for the lack of previous success in predictions regarding future climate changes.

  9. One indicia that CAGW has pretty much run its course is the increasing shrillness and ‘precision absurdity’ ever more evident in ‘earnest’ warmunist pronouncements. This is just another classic in a long list of same, starting with Hansen’s ‘West Side Parkway under water’ circa 1990, middling Viner’s ‘Children won’t know snow’ circa 2000, and more recently Wadham’s ‘Artic ice free’ circa 2010. Not to mention Hayhoe’s 2011 Texas permadrought or Schellnhuber’s many previous tipping points, none of which have yet tipped.

    • The Alarmists have gotten so desperate for proof that they are starting to see CAGW every time a bit of extreme weather comes along.

      I was listening to a CAGW debate on Fox News this morning, and the liberal chimed in with something like, “it’s obvious humans are causing the Earth’s weather to change, just look at Hurricane Harvey and what it did to Texas. This statement shut down the whole argument. Noone on the other side thought to mention that hurricanes like Harvey are a normal part of the weather process, and have been happening long before CO2 was an issue.

      So, claiming that every weather event is caused by CAGW seems to be an effective way to shut up the less knowledgeable among us.

      We should probably work harder to heap scorn on such claims especially since they seem to be coming on a daily basis. You know the old saying: Repeat a lie often enough, and it becomes the truth. The alarmists are repeating this lie every time they get a chance.

      • Tom Abbott – February 13, 2019 at 3:30 pm

        We should probably work harder to heap scorn on such claims

        Absolutely correct, Tom,

        And they should be and have to be CONFRONTED, ….. face to face, …. in front of everyone that is present when said “claim(s)” is made, demanding that they prove and/or explain their claim.

        And one can’t wait until later that day, the next day or next week “to heap scorn on such claims” because the audience won’t be around to hear you ….. and besides, they won’t believe you anyway claiming “sour grapes” on your part.

  10. The Yakima Herald-Republic newspaper carried this story.
    They report the place will be 5.8 degrees warmer and 15.8 degrees wetter.
    I’m not sure what degrees wetter means.
    I think they mean percent, that is, the area will get 15.8 % more rain.
    Yakima now averages 8.4 inches (about) per year.
    The increase will be about 1.33 inches, or 0.0036 in. per day. No one will notice.

    The 5.8 degrees warmer is complete nonsense.

  11. The UK Met Office once promised us that global warming was going to deliver us a “Mediterranean Climate”.

    Of course most of the UK population decided they quite liked the idea of a perpetual “Year in Provence” and went out on a barbecue-buying spree, only to be rather quickly disappointed. The Met Office soon realised that they were now losing on two counts, and decided to shut up about such comparisons.

  12. Yes, as Charles suggested, the models have a reputation for regional forecasts from different models being contradictory, particularly for precipitation. I find it improbable that coastal areas, where the local climate is moderated by the proximity of the ocean, will shift the climate to be more similar to areas in the continental interior. That should have been the first clue to the modelers (and the MSM reporters) that there is a problem besides relying on RCP 8.5!

  13. One good thing: in 60 years we(surviving Anti-anthropomorphic-global-CC’ers) can point out that their 2-sigma regional 12-variable future climate projections that have large dissimularities to present urban climates are horse-Huey. And force it down pompous scientists and journalist heros past and future so this never happens again. 540 scenarios I am figuring they will have 539 wrong

  14. What hubris to think you could do this.
    But of course, the goal is to create another tool for propagandizing the public on the issue, not to do science.

  15. I live in Michigan. Other than the ice fisherman, the rest of us would like the climate 800 miles south of us. Do these fanatics ever think about all the people that move south to enjoy warmer temperatures.

  16. By 2080 Canadian cities will be warmer. In fact the whole world will likely be warmer. Ice sheets and glaciers will melt to some degree. The sea level will rise. Oceans will warm. Unusual and extreme weather patterns may evolve. The biota will be affected and not all species will fare well. And on and on.

    All of the things we have been taught to fear and to “tackle” are common in interglacials. The information content of the sum of their fearology is that we are in an interglacial and not a particularly active one at that.

    Hats off to the propaganda geniuses who sold us an interglacial as a man made horror from which man can and must SAVE THE PLANET.

    https://tambonthongchai.com/2018/12/21/eemian/

    https://tambonthongchai.com/2018/12/25/youngerdryas/

    https://tambonthongchai.com/2018/12/27/nasa/

    https://tambonthongchai.com/2019/02/03/hidden-hand/

    • I’ve always wondered about how many species will go extinct when the next ice age starts. It seems species go extinct when it gets warmer and when it gets cooler, at least those that can’t/won’t adapt. If the Precautionary Principle means anything, shouldn’t we be studying how to prevent species extinction with the coming of the next ice age? I would think that starting from a warmer point would ameliorate some of the danger.

  17. So… I just plotted approximately 500 miles south and its Monterrey, Mexico. The average temperature there in August is 3 degrees cooler than Dallas. OK! I am “cool” with this! Bring it on!

    This article is just ridiculous. Stalin would be proud of the kind of propaganda produced by the loons of AGW.

  18. I live in Central Ohio. The linked app is unavailable. But, I looked a the maps in the paper. As near as i can tell I am moving to Evansville IN. But, if it is RCP8.5, I am going to Cape Girardeau MO. I don’t see either of those fates as being worth any effort to avoid. I certainly would not support a tax increase for that purpose.

  19. I have previously written 2 articles, which have a similar theme to this study.

    In January 2019, I wrote, “How far would you need to move towards the nearest Pole, to reverse one degree Celsius of global warming?”

    https://agree-to-disagree.com/how-far-to-reverse-global-warming

    ====================

    In August 2018, I wrote, “Solving Global Warming is easy”

    https://agree-to-disagree.com/solving-global-warming-is-easy

    ====================

    A warning, my articles contain large amounts of Monty Python type humour.

    It is best to have a few drinks, before you read my articles.

  20. The biggest “disconnect” here appears to be between the authors’ brains and reality.

    I presume this piece of make-believe was done on the taxpayers’ dime. Can’t we do them for fraud or something?

  21. @tfa
    <blockquoteWithin the lifetime of children living today, the climate of many regions is projected to change from the familiar to conditions unlike those experienced in the same place by their parents, grandparents, or perhaps any generation in millenia
    Sounds like a _denial_ of recent CC

  22. After reading this it occurred to me that finally after denying for decades that the UHI exists, the CAGW proponents are now writing about how large and significant the UHI will become. I wonder if Phil Jones is aware of this.

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