Today, we are pleased to present a guest contribution written by Nelson Mark, Alfred C. DeCrane Jr. Professor of Economics (U. Notre Dame).
A central problem addressed in climate change economics is the estimation of economic costs of climate change. Because climate is a slowly evolving phenomenon, not well suited to econometric analysis, empirical economists use weather (e.g., temperature and precipitation) to proxy for climate. Empirical research has used international temperature and per capita GDP data in panel regressions of a country’s GDP growth on country temperature. A coarse consensus is that higher temperature economically damages hot and not-so-rich countries but there is no (statistically significant) effect on cooler and rich countries.
The absence of effect on the rich countries could be viewed as a problem. Industrialized countries are the primary contributors to the current stock of greenhouse gasses but if they don’t bear economic costs, what incentive do they have to invest in climate mitigation? Nicholas Stern appeals to ethical considerations to get action from rich countries. First, rich countries, through mechanized production since the industrial revolution, have largely created the problem, and second, poor countries are just beginning to overcome poverty through rapid growth and should not be forced to slow.
These panel regressions discussed above, constrain the GDP growth response coefficient to higher temperatures to be equal across countries although a limited analysis of differences across countries (i.e., rich versus poor) can be done through the use of dummy variables.
Instead, if one estimates the GDP response to a (positive) temperature shock individually for each country, one finds a lot of heterogeneity in response. This figure shows the impulse response of a country’s log per capita GDP to a one-degree Celsius increase in temperature at horizons of 0 to 7 years after the shock. Some poor and hot countries are hurt by higher temperature while others, surprisingly, seem to have benefitted. Rich countries are more likely to be hurt. Per capita GDP in 6 of the G-7 countries show declines following a temperature shock.
Source: Berg, Curtis, Mark, 2021, “GDP and Temperature: Evidence on Cross-Country Response Heterogeneity,”
To get a more comprehensive view of cross-country differences in responses, the top panel of the map figure shows the contemporaneous GDP response and the bottom figure shows the 7-year ahead response to a temperature shock. Positive responses are green, negative responses are red. Darker shades indicate statistical significance at the 5 percent level. In the bottom panel, higher temperature, has been good for very cold countries (Canada, Greenland, Russian Federation). This makes sense because lessening the extreme cold of those countries can extend growing and construction seasons, and improve production efficiency in general. Oddly, positive temperature shocks have been good for China, India, Brazil, and several African countries.
Source: Berg, Curtis, Mark, 2021, “GDP and Temperature: Evidence on Cross-Country Response Heterogeneity,”
To characterize these response patterns in a more systematic way, let’s run a cross-sectional regression of the horizon 7 country response coefficient on country characteristics: latitude, per capita GDP, long-run growth, and the relative importance of agriculture, industry and manufacturing. No need to dwell on the actual numbers—I’ll just indicate the coefficient sign and whether it is statistically significant (with a *)
Source: Berg, Curtis, Mark, 2021, “GDP and Temperature: Evidence on Cross-Country Response Heterogeneity,”
After controlling for latitude richer and faster growing countries are hurt by higher temperature. Countries with a larger manufacturing sector are also damaged by temperature. These results align with the evidence that heat lowers labor productivity and labor supply in manufacturing.
Curiously, countries where agriculture plays a larger economic role are more likely to have benefited from rising temperature. This seems to go against the conventional wisdom whereby agricultural labor should be the most directly exposed to hot temperatures and where crop yields should be damaged by heat. It is, however, consistent with the inverse relation between response and income, since poor countries have larger agricultural sectors.
GDP of countries with a larger industrial share (manufacturing, mining, construction, electricity, water, and gas) have benefitted, possibly because warmer weather extends the number of operational days in construction and mining.
There seems to be substantial heterogeneity across countries in the way temperature impacts GDP. Temperature shocks have resulted in significant economic damage to rich countries. They should be incentivized to invest in abatement policies out of self-interest.
This post written by Nelson Mark.
Especially important and useful paper.
https://english.news.cn/20220417/b3ccc71c62634c0d9fa93d17443cb2c1/c.html
April 17, 2022
Major lakes in Qinghai-Tibet Plateau see significant water increase
BEIJING — Researchers have discovered that the total water volume of ten major lakes across the endorheic region of Qinghai-Tibet Plateau increased by 58.5 cubic kilometers between 1979 and 2016.
Rainfall, glaciers and snow meltwater, lake surface evaporation, and soil freezing-thawing are the major contributors to the water increase, according to a recent research article published * in the journal Science Bulletin.
The endorheic area of the Qinghai-Tibet Plateau contains more than 60 percent of the total water storage of lakes in the region. The complex topographic conditions and the interactions among the cryosphere, hydrosphere, and atmosphere in the high altitude area limit understanding of most lake basins of the Qinghai-Tibet Plateau.
The researchers selected ten large lakes with an area of more than 500 square kilometers and quantitatively evaluated the variation of lake water storage and its driving factors in the endorheic region of the Qinghai-Tibet Plateau, which provides important scientific support for analyzing the hydrological process of the lake basin and the role of the cryosphere in lake expansion.
The researchers came from the Chinese Academy of Sciences and the University of California.
* https://www.sciencedirect.com/science/article/abs/pii/S0048969721005313?via%3Dihub
Endorheic – “Of a basin or lake: having no outflow to an external body of water such as a river or ocean, and only losing water through evaporation or seepage into the ground.”
Cryosphere – “The frozen water part of the Earth system.”
Interesting conjectures.
Bruce Hall: Dr. Mark’s estimates are based on data already observed. I do not see how they are conjectures. Or, then every other VAR estimated since Sims’s paper is “conjecture”. Man.
I can’t make out what is the deal with people. Arguably the best TV/local meteorologist (no, not climatologist, but still) who has ever walked planet Earth, Gary England (retired now and doing advisory work at Oklahoma University) has his entire career denied global warming. He’s a pretty sharp guy and a guy that for over 40 years 90% of Oklahomans would turn to when there were tornado outbreaks etc. Yet to this very day he will use his Twitter account to scarf at global warming and how global warming is changing temperatures and weather systems/patterns. Unless he is cynically just telling dumb Okies what they want to hear, figuring he can use that for commercial means, it really is flabbergasting. He is a man who has more than enough intelligence and education to know better. The ability of what I would call “culture pockets” and politics to warp people’s minds is really…. and I hate to use this overused word….. unbelievable.
Well Bruce worked in the car business, and most Michiganites are conservative, so , you tell me what is going on there.
This isn’t hard. Bruce Hall is nothing more than MAGA hat wearing political hack. He knows what he writes is clearly wrong but he writes it anyway. He pretends to be having a honest discussion even though everything he writes is one long winded lie after another. Now this troll actually thinks he is fooling people but tell me – is there a single person here that finds his comments even remotely useful. Not me – not you – not Menzie. No one.
Yes, but they’re at the national level. I’m surprised we still do these sorts of regressions. Esther Duflo would flip her wig.
When the science of estimating temperature change and economic impact becomes more granular, it then becomes more meaningful. Is the west coast impacted more than the east coast? Will the Midwest/Great Lakes region benefit from warmer temperatures. How will precipitation change on a granular basis? Will the west continue its drought or is that related to the predominance of El Niño rather than La Niña?
First predict temperatures at this level: https://www.ncdc.noaa.gov/monitoring-content/sotc/national/countytavgrank/countytavgrank-202201-202203.png
Then predict precipitation at that level: https://www.ncdc.noaa.gov/monitoring-content/sotc/national/countypcpnrank/countypcpnrank-202201-202203.png
Then predict the economic impact at that level based on changes in temperature and precipitation. Then we can discuss the assumptions,
Ah yes – this is why you called the post “interesting”. Another chance for climate change denier Bruce Hall to concoct his usual intellectual garbage.
Come on Brucie – everyone here knows you are a serial liar. We can discuss what assumptions? The case is closed. You misrepresent everything.
Ah, Lucy, again with the Liar meme. You should know better by now that is tragedy of a mind incapable of actual debate.
Keep up troll. I have documented the FACT that you lie a lot. Of course you move onto your next set of lies. Sort of like Trump. Actual debate? You do not even try to engage in an honest discussion or debate.
Lucy,
No, you haven’t documented anything; you’ve simply repeated your assertion… which is false… which I guess makes you the liar.
Hi Bruce,
Yes, you are right. And in fact many people are already attempting to estimate climate effects at a very granular level as you suggest and there are a number of commercial products available now. Moodys 427 and Jupiter Intelligence are a couple of examples, but there are others. I’ve also done quite a bit of highly granular climate estimation. For example, I’ve estimated climate risks such as wet bulb globe temperature at a highly granular level for the entire earth at different times from now to 2100 AD. I do believe it’s necessary to derive economically relevant measures from global circulation models and then apply them at high granularity to the laborious and highly uncertain task of estimating economic and financial consequences.
Rick,
So, you have been making these estimates. Are they better than those made by others? Have you adopted a superior methodology to that used by others?
Bottom line: have you gotten your estimates published by a refereed journal? Would you even dare to submit them to such a journal? Or do you just go around bragging about them on various blogs while protecting your identity behind your embarrassing fake name?
Barkley,
I was merely letting Bruce know that indeed people are producing very granular estimates, and cited myself and some sample commercial vendors as examples. Not sure why that’s an occasion for you to demand that I publish in an academic journal. Besides, I only care about what’s useful, not what’s publishable.
Rick,
Oh, are your particular set of granular estimates for sale and are people actually paying for them? Where might they be available then? That might be a substitute to some extent for publishing in a refereed journal, which is still superior. After all, there are a lot of suckers out there, and you engage in a lot of outright misleading trollish posting, which I am sure you do elsewhere, perhaps without people around able to point out how you are not messing up.
BTW, pretty funny that on the one hand you brag about making all sorts of granular estimates, but then attempt to sell a toy model so aggregated as to be totally useless here. What a joke.
“while protecting your identity behind your embarrassing fake name?”
His name does show up as a porn star.
When THE RICK endorses some rightwing troll, we have entered THE ONION territory!
Important question for both Rick and Bruce:
Do you actually know how to perform these calculations? Have you done anything like this professionally? (I haven’t and I don’t, but I don’t pretend like I know.)
This is important. Shooting the shit in the comments like a precocious grad student is one thing. Actually knowing how to do these very tough calculations properly is another thing. These are macro models from hell.
AndrewG,
Yes, I do know how to do these calculations. See my estimates for Barkley Rosser below.
When the science of estimating temperature change and economic impact becomes more granular, it then becomes more meaningful. Is the west coast impacted more than the east coast? Will the Midwest/Great Lakes region benefit from warmer temperatures. How will precipitation change on a granular basis? Will the west continue its drought or is that related to the predominance of El Niño rather than La Niña?
First predict temperatures at this level: https://www.ncdc.noaa.gov/monitoring-content/sotc/national/countytavgrank/countytavgrank-202201-202203.png
Then predict precipitation at that level: https://www.ncdc.noaa.gov/monitoring-content/sotc/national/countypcpnrank/countypcpnrank-202201-202203.png
Then predict the economic impact at that level based on changes in temperature and precipitation. Then we can discuss the assumptions,
You repeated that trash a 2nd time? Repeating a pack of lies does not create the truth. Stop wasting our time as we are all on to your game.
conjectures? I guess this is something else you did not read. Nelson Mark’s paper is thorough and excellent research as lying climate change denying twit like you calls this conjectures? You are beyond disgusting. And we cannot wait for your “interesting” to be your usual total misrepresentation of his research. You know Bruce – you can the world a favor if you took your usual rightwing lies to another blog where they do not care about actual research.
Professor to class: life expectancy in this country is 80 years.
Student: what is observed range of longevity?
Professor: 0 to 115 years.
Student: then the average might mean something, but not without specific context.
Professor: nobody is perfect.
Within the US alone, there will be areas of worsened conditions and those of improved conditions if there is an increase of “average” temperature of 2ºC. Climate is not monolithic. If, for example, the western third of the nation becomes hotter and drier, there may be less water available for the west coast. The Midwest/Great Lakes/Northeast may find life a bit easier if winters abate somewhat. Since there is more manufacturing in the north and east, that would help conditions and potentially reduce costs. People might be more attracted to the Great Lakes regions where there is ample water and power.
So, yes, interesting conjectures, but not very meaningful. The devil’s in the details.
See our host’s comments which called out your pathetic little insult. Details? A parade of blatant lies is your details.
Lucy, your vocabulary seems to be limited to a few random words interspersed with the word “lies” or “liar”. It’s all rather vague because you are never specific. Perhaps vagueness is a feature of your mind. The assertion of “lie” is meaningless without a specific context. Keep trying, though. You are entertaining. I share some of your efforts with acquaintances for a good laugh.
Mary, quite contrary. Would you like to tell us why there is so much blood on your lamb’s supposedly white fleece?
Barkley, as I said to pgl, please be specific with regard to Mary, quite contrary. Would you like to tell us why there is so much blood on your lamb’s supposedly white fleece?
Are you having a problem with what I wrote?
Within the US alone, there will be areas of worsened conditions and those of improved conditions if there is an increase of “average” temperature of 2ºC. Climate is not monolithic. If, for example, the western third of the nation becomes hotter and drier, there may be less water available for the west coast. The Midwest/Great Lakes/Northeast may find life a bit easier if winters abate somewhat. Since there is more manufacturing in the north and east, that would help conditions and potentially reduce costs. People might be more attracted to the Great Lakes regions where there is ample water and power.
Do you believe the western third of the nation has the same general climate as the Midwest and Northeast? Maybe the South? I don’t believe you do. Do you believe that milder winters in the Midwest/Great Lakes/Northeast would not make like easier and less expensive? I don’t believe you do. Do you believe that people from other regions would not be attracted to a Great Lakes region with a milder climate, manufacturing jobs, and plenty of fresh water. I don’t believe you do.
So, Barkley, where is the blood on my fleece?
The research described here, both the author’s own and other research he discussed, is based on historic data. If climate change leads to changes in conditions which differ from those represented in the data, we can expect even worse outcomes.
Mark mentions the combined effects of temperature and humidity on hunan ability to do physical labor. Turns out, wet-bulb temperature is a key issue:
https://www.science.org/doi/10.1126/sciadv.aaw1838
https://iopscience.iop.org/article/10.1088/1748-9326/aaa00e
Since every 1 degree rise in air temperature allows for a 4% increase in the capacity of air to hold water vapor, wet-bulb temperature can rise quickly with average temperature rise.
The Southeast of the U.S. is among the areas likely to be affected.
Parts of the western U.S. have experienced prolonged droughts. Our government expects drought to become common for most areas west of the Mississippi. (Where will I get hops if the Cascades dry up?) Sea level rise is likely to make some highly populated areas unlivable.
Each of these conditions will contribute to internal migation.
Mark is working with data which do not reflect these changes, but even so show more widespread economic costs from climate change than had previously been reported. The pattern has been that the effects of climate change are accumulating faster than expected, and now we see that the costs are more widespread than we knew.
The ghost of climate change present is mild compared to the ghost of climate change future. Dickens’ message is clear; mend your ways while there is still time.
Some one actually read this research and grasped its implications. I would ask you to tell Bruce Hall what this really means but yea I get it – his trash is a complete waste of your valuable time.
Interesting conjectures.
Oh my – you actually think repeating your stupid disgusting lies makes them honest contributions? Are stupid are you? Never mind – we all know you are the dumbest troll ever.
Big, important look at the interaction of climate and human welfare. Standard tools, new knowledge. That’s what creative scholarship can do.
Yes, this is right. One of the key feedbacks in physical climate change process is the increase in water vapor and precipitation. But when humidity goes up for a given temperature, the effect of the increase in temperature becomes more pronounced. Studies that attempt to capture the historical relationship between temperature and GDP will not capture this effect.
Interesting…positive for Russia and China…bad for NATO. But I doubt it’s enough to spur NATO to get serious about climate change, not hegemony.
Turning a paper on climate change to an apology for Putin’s war crimes. You are one sick puppy.
All the more reason NATO countries should not buy Russian oil.
Oh, and Mark’s analysis does not examine the likely result of climate change on Russian’s welfare through non-temperature environmental factors, such as fires, floods, and such, nor through side-effects such as migration. So even for a stupid little bit of “hurray for my team” cheering, your comment was pretty dumb.
“hegemony”
I don’t teach political science but if I did, and you were in my class, I’d bop you over the head many times with James Hamilton’s textbook.
Can anyone find a definition for “temperature shock”? Using the term in the title and throughout the paper without clearly defining it may be confusing to those trying to understand a new concept/term. It can certainly lead to conjecture or false claims from those not trying to understand.
In economics, a shock is a change in a factor exogenous to to model. Few, if any, standard economic models include climate variables as endogenous factors. So a change in temperature which induces changes in the perforance of the economy is a shock.
Standard econ lingo. No mystery.
This also means that we don’t need to fuss about what size change constitutes a shock. Any sized change in an exogenous factor is a shock. Some shocks matter. Others don’t.
Weather (heat waves, snow storms, floods) and climate (the Little Ice Age) have long been recognized as sources of economic shocks.
MD defines “temperature shock” as: “In economics, a shock is a change in a factor exogenous to to model…. Standard econ lingo. No mystery.” and “Any sized change in an exogenous factor is a shock. Some shocks matter. Others don’t.
Weather (heat waves, snow storms, floods) and climate (the Little Ice Age) have long been recognized as sources of economic shocks”, but defining economic shocks do not define temperature shocks.
The paper apparently focuses on warming. “We find three primary results. First, higher temperatures substantially reduce economic growth in poor countries. Second, higher temperatures may reduce growth rates, not just the level of output. Third, higher temperatures have wide-ranging effects, reducing agricultural output, industrial output, and political stability.”
How the analysis is done: “This paper takes an alternative approach. We first construct temperature and precipitation data for each country and year in the world from 1950 to 2003 and combine this dataset with data on aggregate output. ” BTW, the dataset used is land only.
So far there are many questions regarding the limits considered by this paper.
CoRev: So, then I expect you to provide some useful critique, such as how much using over-ocean temperatures would change the results (given that most countries to my understanding are “on land”), and more interestingly to me, use of say local projection methods might introduce biases. I await with bated breath for your econometric critique.
As the paper mentions, the amount of agriculture in any particular country’s GDP would play a major factor. I was trying to think…….. didn’t Menzie and CoRev have some minor disagreement about a particular Midwestern USA food crop?? Something about Brazilian farmers making a mint off of trumpian trade tariffs?? Seems Menzie “got the better of” CoRev in that debate. Hmmmm, my memory is foggy, what ag crop that was…….. maybe Barkley can remember. Baaaaahahahahahahahaha!!!!!!
Menzie, I continue to be amazed by your and many of your readers acceptance of an elitist and racist Premise. “At least since Montesquieu’s The Spirit of Laws (1750), which argued that an “excess of heat” made men “slothful and dispirited,” it has been debated whether temperature is, or is not, central to understanding economic development.”
Having questions over a paper is no longer valid, but requires the questioner “to provide some useful critique”. I await with bated breath for your definition of “Temperature Shocks”. Without that an “econometric critique” is impossible.
You say so little with so many words. Is this your contribution to life – wasting everyone’s time with incressant word salad?
Some people will argue this is self-evident, but the top of page 34 bears highlighting in my opinion:
“Projections in regional IAM models Nordhaus and Yang (1996) and the Anthoff-Tol FUND model used in Tol (2020) also predict that greater economic damage for hot, poor, and lower latitude countries than cool, rich, and high latitude countries specified in the Stern report (Stern, 2007), which argued high latitude countries such as Canada and Russia stand to benefit from warming, while poor countries are most vulnerable due to higher geographic exposure, fewer resources available for mitigation, and poor quality housing. Also, Alvarez and Rossi-Hansberg (2021) estimate the greatest welfare losses (up to 15%) will occur in hot regions such as Africa, India, and Australia but also significant welfare gains (up to 14%) in the cold regions of Alaska, Northern Canada, and Siberia. In contrast, we project losses for rich countries. Except for Canada, losses are projected for the G-7 under both the low and high emissions scenarios.”
Apparently some of their results on agriculture are counterintuitive, which (and this is NOT a criticism of the authors’ methods) is kind of bewildering.
I wonder where our good friend CoRev got the Montesquieu quote from?? The very first sentence in some paper related to temperature shocks??
https://scholar.harvard.edu/files/dell/files/aej_temperature.pdf
Aside from giving proper quote attributions and drawing weird inferences of “racism”, at least we now know CoRev is searching out answers on Google. This begs the question, “What happens when you give low-intelligence beings a laptop connected to a search engine?? Good things, or bad things??” We have one small data point.
You damnded blasded weisenheimers. Puh-huds…… and stuff. I’m sticking with Sarah Palin on this topic, she used to be a TV sportscaster.
EVERYONE (except for the village idiot Bruce Hall) knew what the author meant. CoRev is just pretending to be THAT DUMB!
Bierka, then define “Temperature Shock”. At least MD tried to define climate & weather economic shock. Even there the list included cold not just warm impacts. A comparison of these two would indeed be meaningful. Only ideologues want to only look at the warming impacts.
Moses, the quote came from Menzie’s reference in this article. you really should folloiw the links.
And I suggested your dishonesty had a tinge of intelligence (as opposed to that Bruce Hall chirping) but maybe I am overestimating you.
I am going to throw water on this study. I get that it is based on panel regressions from past data. But that does not mean this is all that useful for projecting forward the relevant effects.
The obvious example that sticks out is Bangladesh. This study has it experiencing positive economic growth in response to rising temperature, both immediately and after seven years. It may be that this has been recent experience. But there is strong reason to believe this will not hold going forward, and a long list of experts and official entities are projecting that Bangladesh will suffer severe economic consequences as global average temperature rises, with a 2-9% decline in GDP highly likely.
The problem is the low altitude of most of the country, two thirds of it not more than two meters above sea level. Any significant rise in sea level will damage it badly, with substantial portions of the population being forced to move, and with flooding affecting even areas not going under the ocean. The government of Bangladesh itself issued an official report detailing these problems back in 2009.
I am not going to provide links, but googling “Bangladesh economic impacts climate change” will provide a long list of sources on this, among them the UN, the Stern Report, the Asian Development Bank, and the World Bank, along with others. Nobody aside from this paper is suggesting that Bangladesh will gain from global warming.
@ Barkley Junior
You have an interesting way of looking at research. Do you sincerely think that the paper is arguing that Bangladesh would benefit from global warming/climate change?? Or do you think they include so many countries in the paper because in fact the researchers are well aware there will be a few individual country results not reflective of reality, and that by including a large number of countries that could help “cancel out” the countries in discrepancy with the general/overall result??
I think having you as an editor of a scholarly journal must be a “fascinating” process for those making academic paper submissions. I feel empathy for those who have done good/efficacious work and sent it to your door.
Moses,
I note that you yourself above in this thread cite several studies that forecast Bangladesh will suffer from global warming, one of them, the Stern Report, one I mentioned. If the researchers are “well aware that a few individual country results not reflective of reality,” then why are they putting those results out there with little recognition of this? Yes, they do note others disagree with them, but they offer no explanation of why there is a difference.
I think I know why there is a difference, and I have sort of tried to explain it, if not very well. Basically there model, which is linear, simply assumes that what happened in the past will continue to happen in the future in a simple linear way. But there is good reason not to believe this with all these other sources figuring this out and trying to account for it. Further warming changes the conditions underlying the model, making it incorrect. Their model simply cannot forecast that turning point most see coming after anothet i degree C or so of temperature increase.
BTW, there is a Novel Prize winner out there whose name I shall not drop so as not to get you too annoyed who has publicly claimed I am one of the three best economics journal editors he has ever encountered. Your comments on my journal editing are more ignorant and stupid than your usual dreck here. The real joke is that you actually agree with my main point, but just cannot live with that, wanting somehow to find some fault with me. Hilarious.
I didn’t “cite” them, I was verbatim quoting the paper itself. The same paper you fantasized in your personal bizarro world was articulating that Bangladesh will transform into Utopia due to global warming. Your ability to refashion reality so as not to face the fact your statements are severely error prone is only matched by your “brother-from-another-mother” JerseyKopits.
You’re getting at an age, where facts are intermingling in your mind, and emerging out of your mouth/keyboard as fantasyland. And “the non-name drop name drop” isn’t convincing anyone here you’re not holding on for dear life. This is a cue for you to do something before you seriously embarrass yourself. Anyone who cares about you, better let you in on this fact, before the embarrassment becomes indelible~~even to you.
Moses,
Looking at what you wrote here, it looks like you are doubting that the paper says that global warming would benefit Bangladesh. Now I did not read the whole paper, I just looked at the maps that Menzie provided and his summary. And they show Bangladesh colored green, which means not only positively gaining from a “temperature shock,” but doing so strongly. This is what triggered my comments.
@ Professor Rosser
That’s fine and dandy, and I can make out green, light green, red, and pink the same as you. Along, as well, I can read table numbers. But they are using a “model” correct?? Now if you plug in a large number of countries into a model, and a few of those countries give results contrarian to their overall argument, does not mean that they are proponents of the message being sent from that one country?? All they are doing is staying true to their model (unlike Rogoff and Reinhart, making up $hit as they go along) and reporting that individual country’s results. That doesn’t mean they are saying that is indeed the case that global warming helps Bangladesh–it is just the result from the parameters they set for the model. I know (and knew) very well what you were looking at when you made those….unadvisable statements about the paper. The problem is your conclusion that because they got a result contrarian to the overall message of their research in a particular single country, means they are saying that will be the case for Bangladesh going into the very distant future.
Moses,
What is the matter with you? This is just effing nuts.
First of all, Rogoff and Reinhart, did not “make up s**t as the went along. They had an error in their data. They did not figure that out until they went out and made fools of themselves.
You are just completely out of it claiming that I am making “unadvisable statements” about this paper. Heck, Rick agrees with me, and we do not agree on quite a few things. He noted that it is not just Bangladesh but also a bunch of central African nations. Heck, it is also India and Indonesia, two of the largest nations in the world. No, it is much worse than just Bangladesh. I just pointed it out because, again, its case is so dramatic.
Look, that does not mean this is not a worthwhile study. As Rick noted, it is well done. Their methodology is fine. The problem is that their model is not able to take into account how the relation between climate and economy will change for many of these nations, not just Bangladesh, will change as global temperature continues to rise substantially. So it would be unwise to take too seriously projections based on this model of how the economies of various nations will react to further increases in global temperature, especially beyond a degree C of increase in global average.
Upon relooking at this study and thinking further, I am struck that it fits with the prediction of the UN IPCC, which forecasts an increase in world GDP for another increase in global average temperature of 1 deg C. It is increases beyond that level that are projected to bring about declining world GDP. I note I have pointed out this point of an increase in world GDP for that projected 1 deg C here several times before.
So, thinking about it, obviously there is a structural change that is likely to happen at about 1 deg C increase. That what we have seen happen so far, what is in the data underlying this study, do not include any temperatures above that point where the IPCC sees the world economy behaving differently than it has at lower temperatures. The case of Bangladesh is a good example of how this might come about: temperature increases so far have not hurt the nation. But beyond a certain amount of temperature increase, the rising sea level will have major negative impacts not caught in the data from periods when the global average temperature was lower.
Barkley,
I think Mark et al’s paper is a well-executed study that broadly speaking is consistent with other research in this area. GDP loss is relatively small for highly developed countries, for example. I do like the paper. As you point out, the difference is that the paper finds some unusual results for some countries, such as in central Africa and Bangladesh. I must agree with you that these results don’t seem plausible. But I think Mark et al are right to focus granularly as they did. But if you do focus granularly, you really have to take into account the local economy, local vulnerabilities, etc. which a VAR really won’t do.
Rick,
You are too impressed with anybody doing “granular” studies. You need to read more. They are a dime a dozen. Everybody is doing them. The large literature that I partially cited and Moses further cited that disagrees with the findings here on Bangladesh in particular are all granular, every single one of them. These guys are just projecting forward relationships found from past data that it is pretty easy to see are unlikely to continue to hold up with substantial further temperature increases.
Frankly, I am not sure why Menzie posted this study. It is almost embarrassingly out of line with so much other well done literature.
More to the important point, have any of the paper’s authors stroked your ego in the last 10 years?? OK, I’ll settle for one of them eating at the same McDonalds as you have, nearby any U.S. Interstate. And if none of the paper’s authors have given you a noogie right on your shiny bald spot, to hell with the whole lot of them.
Moses,
You have been seriously incoherent on this thread.
First of all, sorry, but I do not make comments on other peoples’ work based on whether or not they have “stroked my ego.” I have rejected papers for publication on numerous occasions by people who have done so. I have rejected papers by personal friends and also by Nobel Prize winners. But, needless to say, I am not going to provide any details on any of that. In any case, you are totally trollishly full of it on this.
As for this paper, I do not know any of the authors and have never had anything to do with them one way or the other. But, as even Rick Stryker notes, it is not just Bangladesh for which the projections look inconsistent with this large other literature out there that attempts to take more carefully into account how further global warming will actually impact these nations, not just by projecting forward results of an econometric model based on past data.
I note that another nation most of these models see as being damaged eventually but shown to have a positive outcome in this model, is Bangladesh’s neighbor India. And here we are now seeing all time record temperatures there. Is that good for the economy there? I seriously doubt it. But I brought up Bangladesh rather than India because the percent negative effect is projected to be larger there than in much larger India, with Bangladesh’s very low altitude just so obviously a problem for it given any substantial increase in global average temperature.
Moses,
In fact, as an editor, I have published papers in journals I edit written by people I do not personally like and which strongly disagree with my views. I have done this on numerous occasions. But I have done this when i thought their papers were making strong and well-stated arguments. I play it straight as a journal editor possibly too straight.
I am not like you who has a stupid set of lists like some third rate Richard Nixon of friends and enemies. You overpraise certain individuals who are the good guys on your list, but then you go out of your way to make off-the-wall accusations against people who are bad guys on your lists, even when they agree with you on most issues, which happens to apply to me. You have your sick vendettas and are not a professional economist. For me, at least when it comes to professional economics, I put aside my personal feelings about people.
Barkley,
Here’s what granular means. Using the Geophysical Fluid Dynamics Model (GFDL) I’d estimate an average wet bulb globe temperature (WBGT) of 27C and annual precipitation of 38 inches in July of 2050. However, using the Institut Pierre Simon Laplace Climate Modeling Center model, I’d estimate an average WBGT of 29C and annual precipitation of 46 inches. Both estimates are under RCP 8.5.
Granular means project by Global Circulation Model, at precise times in the future, at highly granular geographical locations, under a specific greenhouse gas scenario. This level of granularity is not “a dime a dozen.” These differences by model do matter. 27C means that people can do moderate work outside effectively continuously, meaning that July in 2050 in Harrisonburg will be fine. 29C means that they should work half to three quarters of the time and rest otherwise–it will be noticeably hotter.
Sorry, both estimates are for Harrisonburg, Va in July 2050
Rick,
This may be the moment to bring up some recent research that is floating around. It looks like forecasts based on granular studies may be especially subject to the notorious sensitive dependence on initial conditions, aka “butterfly effect” of chaos theory. That was in fact initially discovered in connection with climate models, the famous Lorenz attractor. But it looks that this may be especially a problem for these much more localized studies as well. The problem seems to get worse as one reduces the area one is studying and modeling.
Rick provides model estimates for the WORST CASE of RCP scenarios: ” Both estimates are under RCP 8.5.”
And then Barkley responds with: “…But it looks that this may be especially a problem for these much more localized studies as well. The problem seems to get worse as one reduces the area one is studying and modeling.”
Translating Barkley we get: the models start off bad for larger areas are studied and get worse when those considered areas are reduced. Models go from BAD to WORSE. And that’s an argument for climate models?
I think this is a complicated and important thing to try to do, so I don’t want to speak too ill of the authors’ attempts. But besides your critique about sea level rise here Barkley, I would add (as I have briefly above) that we are comparing countries in a regression, which is itself a very controversial thing that we in history/growth/macrodevelopment abandoned 20 years ago. The big issue is that we can’t assume that the financial sector frictions look the same in each country. To do a reasonable job, we’d have to model all the frictions for each country, which may not be feasible. A just-the-facts-ma’am VAR is not going to cut it.
Duflo and Banerjee wrote about this clearly in a chapter in the 2005 handbook on development. I think that was the best and clearest explanation I’ve seen.
Predicting relatively short term area weather differs from finding historical patterns. A weather or temperature shock simply refers to a difference from a defined historical pattern.
https://fred.stlouisfed.org/graph/?g=FwoW
August 4, 2014
Real per capita Gross Domestic Product for China, India, Pakistan and Bangladesh, 1977-2020
(Percent change)
https://fred.stlouisfed.org/graph/?g=FwoY
August 4, 2014
Real per capita Gross Domestic Product for China, India, Pakistan and Bangladesh, 1977-2020
(Indexed to 1977)
https://fred.stlouisfed.org/graph/?g=Nw3i
August 4, 2014
Real per capita Gross Domestic Product for Pakistan, Bangladesh, Indonesia and Philippines, 1980-2020
(Percent change)
https://fred.stlouisfed.org/graph/?g=Nw3m
August 4, 2014
Real per capita Gross Domestic Product for Pakistan, Bangladesh, Indonesia and Philippines, 1980-2020
(Indexed to 1980)
I find it interesting that the variability of regional climates far exceed the project change (worst case) of average temperatures, yet humans function from the frigid winters of North Dakota to the baking deserts of Arizona and New Mexico. Despite that obvious observation, the debate always rages around averages as if that was particularly meaningful.
The most important aspect of any regional climate is water… precipitation. Without adequate water, human enterprise will be limited at any “average” temperature. Associated with precipitation is the number of days with at least partial sunshine which is important for agriculture (and solar arrays). Then there is temperature running behind those. Oh, I forgot governance. People are leaving the wonderful climate of California for the more challenging climate of Texas. Temperature is not on their minds. If government is making a place unlivable, climate is the least of people’s worries.
When you know you live in an historically arid environment, you adapt to that reality using the best technologies available for conserving water. You don’t let trillions of gallons of water run through concrete canals to the ocean; you build containment reservoirs and desalination plants. If oil exploration can occur on the north slope of Alaska and the flat plains of North Dakota and west Texas, then working in an air conditioned factory is not that big of a challenge for manufacturing. Farmers are not sowing seeds by hand or harvesting with scythes; they work in temperature controlled tractors and combines.
Detroit has an average high temperature of 57º and an average low temperature of 41º. Toledo has an average high temperature of 62º and an average low temperature of 45º. Distance from Toledo to Detroit: less than 60 miles. I challenge you to find anyone who can tell the difference between the climates of those two cities in their daily lives.
The arguments about temperature are ignoring the bigger picture.
The paper happens to be terrific, and as for the development of Bangladesh what is critical is working with China on just the sort of infrastructure projects that are meant to protect against and limit anticipated effects of climate change. China is, by the way, in the midst of restructuring broad costal areas with a focus on climate change. Needs for the Chinese coast, are needs for Bangladesh:
https://news.cgtn.com/news/2022-01-08/What-is-China-s-role-in-promoting-inclusive-growth-in-Bangladesh–16Ezmvw13bO/index.html
January 8, 2022
What is China’s role in promoting inclusive growth in Bangladesh?
By Alexander Ayertey Odonkor
https://english.news.cn/20220428/8cd728278ce8403b97c321a202ac664f/c.html
April 28, 2022
Bangladesh port rejuvenated by Chinese dredging
By Liu Chuntao and Naim-Ul-Karim
MONGLA, Bangladesh — In the Sundarbans, a great forest on the Ganges Delta, lies Bangladesh’s second seaport, Mongla, on the River Pashur. Braving the risks, Sun Chuanbo and his local and fellow colleagues have been working on a river channel near Sundarbans leading to the Mongla seaport in Bangladesh.
About a year earlier, Chuanbo had joined the service of the Chinese Joint Venture (JV) firm of CCECC (China Civil Engineering Construction Corporation) and JHCEC (Jianshu Haihong Construction Engineering Company Limited) is dredging the port channel to improve navigability for ships with drafts of more than 9.5 meters, in challenge to Bangladesh’s main port of Chattogram. The current depth of the shallow Pashur channel is less than 5.5 meters, meaning Mongla is underutilized.
COMING BACK TO LIFE
The project involves the risk of cyclones and is frequently interrupted during monsoon season. Sun and some 200 Bangladeshi and 100 Chinese people operate three huge dredgers.
The outer bar area of Mongla has already been dredged by another Chinese JV including CCECC, resulting in the new commission to take work further. Dredger Xin Zi Lang 5 started work in July last year. The vessel can operate in complex conditions with high precision. The others, cutter-suction dredgers Xin Hai Teng and Xin Hai Xu, are the two largest ships of their kind in the world.
Despite tremendous challenges, the Chinese JV firm said it has deployed the world’s two largest non-self-navigated cutter suction dredgers for timely completion of the project and therefore, make the Mongla port fully functional….
While I’ll give you this is still a debatable topic, it has some bad odors of China setting up a debt trap for Bangladesh.
https://news.cgtn.com/news/2022-05-01/Indians-struggle-amid-record-shattering-heat-wave-19G43fs1Yac/index.html
May 1, 2022
Indians struggle amid record-shattering heat wave
Heat waves are common in India in late spring and early summer, but an unusually early heat wave made this March the hottest in India since records first started being kept in 1901.
Not only have people been struggling with the scorching weather since then. The crop harvest is also expected to drop significantly as a result, which could have global implications given the disruption to the food supply caused by the Ukraine crisis.
Gigantic landfills in India’s capital New Delhi have caught fire in recent weeks. Schools in eastern Odisha state have been shut for a week and in neighboring West Bengal, schools have been stocking up on oral rehydration salts for kids.
On Tuesday, Rajgarh, a city of over 1.5 million people in central India, was the country’s hottest, with daytime temperatures peaking at 46.5 degrees Celsius (114.08 Fahrenheit). Temperatures breached the 45-degree mark in nine other cities.
But it was the heat in March that stunted crops. Wheat is very sensitive to heat, especially during the final stage when its kernels mature and ripen. Indian farmers time their planting so that this stage coincides with the country’s usually cooler spring.
One farmer in Sangrur in northern India’s Punjab state said he watched his crop shrivel before his eyes as the usually cool spring quickly shifted to unrelenting heat. He lost about a fifth of his yield. Others lost more.
“I am afraid the worst is yet to come,” he said.
Punjab is India’s “grain bowl” and the government has encouraged cultivation of wheat and rice here since the 1960s. It is typically the biggest contributor to India’s national reserves and the government had hoped to buy about a third of this year’s stock from the region.
But government assessments predict lower yields this year, and Devinder Sharma, an agriculture policy expert in northern Chandigarh city, said he expected to get 25 percent less….
https://www.tandfonline.com/doi/full/10.1080/23792949.2019.1689828
December 6, 2019
A critical look at Chinese ‘debt-trap diplomacy’: the rise of a meme
By Deborah Brautigam
Abstract
In 2017, a meme was born in a think tank in northern India: Chinese ‘debt-trap diplomacy’. This meme quickly spread through the media, intelligence circles and Western governments. Within 12 months it generated nearly 2 million search results on Google in 0.52 seconds and was beginning to solidify into a deep historical truth. Stories can contain truths and falsehoods. Human emotions, including negativity bias, prime us to think in certain ways. This paper retells a series of stories about China’s international involvement, including in Angola, Djibouti, Sri Lanka and Venezuela, that challenge the media’s spin. It concludes with some suggestions about the relationship between academia and the media and policy worlds, and the need for scholars to speak ‘truth’ to ‘power’.
Deborah Bräutigam is the Bernard L. Schwartz Professor of Political Economy and Director of the China Africa Research Initiative at Johns Hopkins University’s School of Advanced International Studies.
https://www.theatlantic.com/international/archive/2021/02/china-debt-trap-diplomacy/617953/
February 6, 2021
The Chinese ‘Debt Trap’ Is a Myth
The narrative wrongfully portrays both Beijing and the developing countries it deals with.
By DEBORAH BRAUTIGAM and MEG RITHMIRE
China, we are told, inveigles poorer countries into taking out loan after loan to build expensive infrastructure that they can’t afford and that will yield few benefits, all with the end goal of Beijing eventually taking control of these assets from its struggling borrowers. As states around the world pile on debt to combat the coronavirus pandemic and bolster flagging economies, fears of such possible seizures have only amplified.
Seen this way, China’s internationalization—as laid out in programs such as the Belt and Road Initiative—is not simply a pursuit of geopolitical influence but also, in some tellings, a weapon. Once a country is weighed down by Chinese loans, like a hapless gambler who borrows from the Mafia, it is Beijing’s puppet and in danger of losing a limb.
The prime example of this is the Sri Lankan port of Hambantota. As the story goes, Beijing pushed Sri Lanka into borrowing money from Chinese banks to pay for the project, which had no prospect of commercial success. Onerous terms and feeble revenues eventually pushed Sri Lanka into default, at which point Beijing demanded the port as collateral, forcing the Sri Lankan government to surrender control to a Chinese firm.
The Trump administration pointed to Hambantota to warn of China’s strategic use of debt: In 2018, former Vice President Mike Pence called it “debt-trap diplomacy”—a phrase he used through the last days of the administration—and evidence of China’s military ambitions. Last year, erstwhile Attorney General William Barr raised the case to argue that Beijing is “loading poor countries up with debt, refusing to renegotiate terms, and then taking control of the infrastructure itself.”
As Michael Ondaatje, one of Sri Lanka’s greatest chroniclers, once said, “In Sri Lanka a well-told lie is worth a thousand facts.” And the debt-trap narrative is just that: a lie, and a powerful one.
Our research shows that Chinese banks are willing to restructure the terms of existing loans and have never actually seized an asset from any country, much less the port of Hambantota. A Chinese company’s acquisition of a majority stake in the port was a cautionary tale, but it’s not the one we’ve often heard. With a new administration in Washington, the truth about the widely, perhaps willfully, misunderstood case of Hambantota Port is long overdue….
DEBORAH BRAUTIGAM is Bernard L. Schwartz Professor of International Political Economy at the School of Advanced International Studies at Johns Hopkins University.
MEG RITHMIRE is F. Warren McFarlan Associate Professor at Harvard Business School.
I wrote out some points which may have gotten lost in the “ether”. This is a shortened version.
Among the factors that affect humans’ ability to thrive, most predominant is water. Those living in the arid west are learning the lesson that recurring droughts in an area prone to droughts requires significant effort to sustain a livable environment. Rather than allowing trillions of gallons of fresh water to wash along concrete canals to the ocean, large underground reservoirs are necessary. Rather than deprive agriculture of necessary water in order to divert that fresh water to coastal cities, desalination plants should have been built. “Oh, but some years we don’t need that.” Yes, but in many years you do.
Next there is the matter of governance. If an “ideal” climate is so important, why are people leaving California for the more extreme climates of Texas (Dallas is different from Lubbock that is different from Austin that is different from Houston)? And if temperature drives the economic fates of a country, why are people leaving the north for the south? Have you ever spent a summer in central Florida or southern Texas?
What is 1ºC (less than 2ºF) to living conditions? Detroit and Toledo are less than 60 miles apart. Toledo is an average annual high temperature and average annual low temperature about 4ºF higher than Detroit. Find someone who can detect the difference in the ability to work because of that temperature difference. With slightly warming temperatures, there is somewhat more precipitation, so in general (despite some regional differences) there should be more fresh water available, right?
https://www.epa.gov/climate-indicators/climate-change-indicators-us-and-global-precipitation Combine warmer temperatures and more precipitation and that should lead to better growing conditions… in general (we love the idea of “global”, right?). As the EPA article presumes, some areas will not benefit from warmer temperatures because they are historically arid (the Rockies and the desert SW) so the slightly higher precipitation will be offset by higher evaporation. Phoenix may have to rethink things. California may need large underground reservoirs and desalination plants. One city recognizes that, but hasn’t done much of anything. https://www.latimes.com/local/lanow/la-me-ln-stormwater-20170308-story.html
… governance.
Now the conjecture is that the US with a temperate climate… in general… is going to suffer economically from a few degrees more warmth. Yet observed economic growth in the US has been toward the warmth. Of course, if poor governance and bad policies raise the cost of air conditioning, those warm places may be made more uncomfortable driving people back toward cooler areas (like Canada?). But when what is observed defies what is conjectured, observations must be wrong.
“Toledo is an average annual high temperature and average annual low temperature about 4ºF higher than Detroit. Find someone who can detect the difference in the ability to work because of that temperature difference. ”
https://www.bestplaces.net/climate/?c1=53977000&c2=52622000
well if somebody were to live in either Toledo or Detroit, they would find that you statement is factually inaccurate. the temperature is about the same throughout the year for the two cities.
bruce, you make your arguments out of strawmen and flat out lies. just a bunch of word salad.
bruce, you make your arguments out of strawmen and flat out lies. just a bunch of word salad.
I just love it when a “educated” commenter has to rely on “lies” and “liar” without doing the simplest fact checking.
Detroit: https://www.usclimatedata.com/climate/detroit/michigan/united-states/usmi0229
Annual high temperature 57ºF
Annual low temperature 41ºF
Toledo: https://www.usclimatedata.com/climate/toledo/ohio/united-states/usoh0953
Annual high temperature 62ºF
Annual low temperature 45ºF
Oops, “an educated” … don’t want a typo to set you off.
well bruce, if you look at the link I provided, you see that the curves are the same and the data is the same between the two locations.
https://www.bestplaces.net/climate/?c1=53977000&c2=52622000
I did do simple fact checking, and provide you with the link. apparently you failed to view the data.
maybe you think your data is better than mine. perhaps that is true. perhaps that is false. so lets go to noaa and get the results for Detroit and Toledo.
https://www.weather.gov/cle/TOLNormals
https://www.weather.gov/dtx/monthlynormals
Neither of us should be in a position to argue about the validity of NOAA data. Monthly average high and low, over 30 years. Overall average presented in last line.
Detroit Toledo
High Low High Low
32.3 19.2 34.7 20.3
35.2 20.8 37.8 22.1
45.9 28.6 48.4 29.9
58.7 39.1 61.5 40.3
70.3 50.2 73.3 50.9
79.7 60.2 82.7 60.5
83.7 64.4 86.5 64.2
81.4 63.2 84.1 62.8
74.4 55.5 77.7 55.1
62.0 44.0 65 44.3
48.6 33.9 51.1 34.5
37.2 25.3 39.4 26.1
59.1 42.0 61.9 42.6
Now my math might be off here, since I did not get the great education of bruce hall and corev. but I see a difference in high temps of 2.7F and low temps 0.8F. What I do not see is the 4-5 degree F temperature difference you are claiming.
this was simply poor analysis on your part bruce hall. the reason these 2 cities feel the same is because they essentially have the same temperature. your 4-5 degree temperature difference is simply an exaggeration. or a lie. a straw man. as I noted to start off this discussion. it was not an honest assessment. it was word salad. you just hoped nobody would actually call you on any of the garbage you present.
“Yes, 4-5ºF, on average difference is “about the same”. Now let’s apply that to climate in general: 2-4ºF change.”
now lets really move on to the dishonesty in bruce halls argument. bruce subtly wants to argue that the DIFFERENCE in temperature between two distinct locations is somehow related to a CHANGE in temperatures at any one location. completely dishonest. we are not saying that Toledo suddenly increased in temperature. first, this is not a coherent argument on your part bruce. second, you are being very dishonest in presenting your argument this way. I guess if you compare the difference in average low temperature in Antarctica to the average low in Hawaii, it should mean that small global climate change of 4 degree F is meaningless? you see the absurdity in your argument bruce? it really is a waste of time even discussing with you. because you are either ignorant or willfully misleading. but you are not honest.
Frankly, I am not sure why —— posted this study. It is almost embarrassingly out of line with so much other well done literature.
[ A churlish comment. The paper is important. ]
Really nicely done:
https://www3.nd.edu/~nmark/wrkpaper/BCM_GDP_Temp_Paper.pdf
August 11, 2021
GDP and Temperature: Evidence on Cross-Country Response HeterogeneityBy Kimberly A. Berg, Chadwick C. Curtis and Nelson C. Mark
Abstract
We use local projections to estimate the cross-country distribution of impulse responses of real GDP per capita growth to temperature shocks. Negative growth responses are found for six of the Group of Seven countries (Canada being the exception) while positive responses are found for four of the nine poorest countries. Temperature shocks have adverse effects on growth for 42 countries and have positive effects for 52 countries. Negative level effects are found for 34 countries and positive level effects for 13 countries. After controlling for latitude, the growth impulse responses are decreasing in average real GDP per capita and in long-term growth. Counterfactual projections under a high-emissions scenario show temperature induced losses in year 2100 of 1.9 percent ($4,837 2017 dollars) of real GDP per capita for the United States.
what a bunch of word salad. glad it was the short version.
Baffled,
You seem to like the phrase “word salad” and the epithet “liar”. Do you and pgl collaborate on your profound retorts?
I did find part of your comment most enlightening:
well if somebody were to live in either Toledo or Detroit, they would find that you statement is factually inaccurate. the temperature is about the same throughout the year for the two cities.
Yes, 4-5ºF, on average difference is “about the same”. Now let’s apply that to climate in general: 2-4ºF change. I provided the links to the data for those cities, but I’ll do it again in case your computer refused to check them out the first time.
Detroit: https://www.usclimatedata.com/climate/detroit/michigan/united-states/usmi0229
Toledo: https://www.usclimatedata.com/climate/toledo/ohio/united-states/usoh0953
I’ve lived in the Detroit area for 50 years. I also lived and worked in North Dakota and Central Florida. I have a pretty good feel for differences in climate and what makes those differences significant.
Barkley,
In reply to your comment , would you mind citing the studies you are referring to? I haven’t seen any recent studies on local projections and initial conditions, but I’d like to take a look. In general, initial conditions overwhelm all of the other uncertainties at shorter horizons in climate models (Lorenz, etc) but tend to fade out at long horizons, since projections are constrained by physical laws. The research I’ve seen is that at 30 years (i.e., around 2050) out initial conditions will still have some effect on uncertainty in climate projections, but at that point it’s more model uncertainty: choice of scenario such as RCP 8.5 vs RCP 4.5 won’t matter that much at multi-decade horizons. I chose to use RCP 8.5 because it’s the most conservative scenario, but it doesn’t matter that much by 2050. Matters much more by 2100 of course.
Emmanuele Massetti and Emmaneualr Di Lorenzo, “Chaos in climate change estimates,” 2020 EGUGA 222181065M
Thanks Barkley. This research indicates another caveat in using these models to project economic consequences.
Barkley, here a graphical depiction of the RCPs https://climatenexus.org/media/RCP-8.5-Neil-Craik-University-of-Waterloo-768×402.jpg
RCP 8.5 represents a CO2 scenario of >1,000 PPM. Does any rational thinker here think that is even possible?
Why would modelers even select RCP 8.5? Why would anyone, except a rabid ideologue, consider these 8.5 model results? Why would a climatologist consistently use these 8.5 model results? Another rabid ideologue scientist?
And yet these rabid ideologues call those who point out these issues liars. Really?!? Follow the science and not the ideology or at least stop showing the depth of your ignorance.
Corev,
Yes, RCP8.5 is an extreme scenario. It assumes that world population grows more than expected,world GDP growth is weaker, and the global economy shifts to coal in a significant way. It was originally developed as an extreme tail risk emissions scenario, but unfortunately people have often adopted it as a “business as usual” scenario, for which it was not designed.
I use RCP 8.5 only to avoid the potential criticism that my economic impact estimates are low because they were based on a benign GHG scenario. And, as I mentioned, the effects aren’t very great at at 30 year horizon. Using the Institut Pierre Simon Laplace Climate Modeling Center model, for example, I’d estimate an average WBGT of 29C and annual precipitation of 46 inches in July 2050 under RCP 8.5 for Harrisonburg Va. Under RCP 4.5, which is a more favorable GHG scenario than the path the world is currently on, I get a WBGT of 28C, with an annual precipitation of 39 inches in July 2050 for Harrisonburg, Va.
Menzie is problably wondering what his summer weather forecast is in 2050. Using the Geophysical Fluid Dynamics Model (GFDL) WBGT peaks in July 2050 at 24C. Using the Institut Pierre Simon Laplace Climate Modeling Center model, WBGT peaks at 26C in August 2050. Both estimates are under RCP8.5. Menzie can relax–the weather will be fine in Madison.