WUWT readers may recall a recent essay titled ‘What global warming really looks like’ – Michael Oppenheimer FAIL where I pointed out the desperate and ridiculous claims by Michael Oppenheimer to try to link the recent Colorado forest fires to global warming climate change climate disruption. He did a miserable job with his claims, and the data from the National Interagency Fire Center didn’t support his claims at all.
It seems Mr. Oppenheimer is again in the news, this time being smacked down due to another example of some shonky science where he and two other Princeton researchers tried to prove that imagined climate driven crop issues in Mexico were creating climate refugees. Here’s the Princeton press release from July 26, 2010. It immediately became a darling story of climate media bloviators from the BBC to Scientific American to Yale 360 who wrote:
Rising temperatures and reduced crop yields in Mexico could force as many as 6.7 million Mexicans to emigrate to the United States over the next 70 years, according to a new study. Researchers from Princeton University, led by atmospheric scientist Michael Oppenheimer, made that projection after studying historical patterns of emigration, climate change, and crop yields in Mexico between 1995 and 2005. Oppenheimer and his colleagues concluded that for every 10 percent reduction in crop yield, an additional 2 percent of Mexicans aged 15 to 65 could emigrate to the United States.
Well, it turns out Oppenheimer’s paper is complete junk, and when the error is corrected by less excitable researchers without an agenda, they find no evidence of a causal link.
Here’s the paper that started it all:
Linkages among climate change, crop yields and Mexico–US cross-border migration (Full PDF here)
Shuaizhang Fenga, Alan B. Kruegera, and Michael Oppenheimer
Edited* by Stephen H. Schneider, Stanford University, Stanford, CA, and approved June 24, 2010 (received for review March 3, 2010)
Climate change is expected to cause mass human migration, including immigration across international borders. This study quantitatively examines the linkages among variations in climate, agricultural yields, and people’s migration responses by using an instrumental variables approach. Our method allows us to identify the relationship between crop yields and migration without explicitly controlling for all other confounding factors. Using state-level data from Mexico, we find a significant effect of climate-driven changes in crop yields on the rate ofemigration to the United States.
The estimated semielasticity of emigration with respect to crop yields is approximately −0.2, i.e., a 10% reduction in crop yields would lead an additional2%of the population toemigrate. We then use the estimated semielasticity to explore the potential magnitude
of future emigration. Depending on the warming scenarios used and adaptation levels assumed, with other factors held constant, by approximately the year 2080, climate change is estimated to induce 1.4 to 6.7 million adult Mexicans (or 2% to 10% of the current population aged 15–65 y) to emigrate as a result of declines in agricultural
productivity alone. Although the results cannot be mechanically extrapolated to other areas and time periods, our findings are significant from a global perspective given that many regions, especially developing countries, are expected to experience significant
declines in agricultural yields as a result of projected warming.
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And here’s the rebuttal paper:
Unobserved time effects confound the identification of climate change impacts (Full PDF here)
Maximilian Auffhammera, and Jeffrey R. Vincent
A recent study by Feng et al. [Feng S, Krueger A, Oppenheimer M (2010) Proc Natl Acad Sci USA 107:14257–14262] in PNAS reported statistical evidence of a weather-driven causal effect of crop yields on human migration from Mexico to the United States. We show that this conclusion is based on a different statistical model than the one stated in the paper. When we correct for this mistake, there is no evidence of a causal link.
Discussion
After the model in the work by Feng et al. (1) is correctly estimated using their data, the statistical evidence suggesting a causal relationship between weather-driven crop yields and emigration from Mexico to the United States disappears. The statistical evidence in the work by Feng et al. (1) is based on an incompletely controlled before-and-after comparison of emigration rates and crop yields across states. Any omitted factor
positively (negatively) correlated with yields and negatively (positively) correlated with emigration rates over time affecting all states confounds this estimated effect. The results in the work by Feng et al. (1), therefore, cannot be given a causal interpretation,because a variety of factors changed during this period. According to the work by Feng et al. (1), these factors included “the effect of NAFTA, the Peso crisis, and changes in US border controls such as increased border enforcement after 2001” (ref. 1, p. 14258); regarding the second factor, after 1994, “the Peso depreciated considerably against the US dollar, doubling the real wage rate earned by emigrants” (1). The work by Feng et al. (1) also points to the “reform of the land tenure system and the opening of Mexico’s economy
through liberalized trade and deregulation of markets” (1), which further impoverished small farmers and rural landholders.
These factors would confound a pure before/after comparison, and therefore, they make it absolutely essential to control for them through time effects. Results from correct estimation of the model suggest that, for the sample used in the work by Feng et al. (1), these factors, and not weather, were responsible for the change in emigration rates between the two periods.
As Sheldon Cooper would say: “Bazinga!”
Dr. Roger Pielke Jr. Sliced this paper up when it first came out, calling it “silly science”. He wrote on Jul27, 2010:
==============================================================
A new paper is out in a journal getting a reputation for silly science that predicts that climate change will lead to a massive influx of Mexicans across the border to the United States. Here is how the LA Times breathlessly opened its news story on the PNAS paper:
Climbing temperatures are expected to raise sea levels and increase droughts, floods, heat waves and wildfires.
Now, scientists are predicting another consequence of climate change: mass migration to the United States.
Between 1.4 million and 6.7 million Mexicans could migrate to the U.S. by 2080 as climate change reduces crop yields and agricultural production in Mexico, according to a study published online this week in the Proceedings of the National Academy of Sciences. The number could amount to 10% of the current population of Mexicans ages 15 to 65.
A reporter emailed me an embargoed copy last week asking for my reactions. Here is how I responded (and I pulled no punches):
To be blunt, the paper is guesswork piled on top of “what ifs” built on a foundation of tenuous assumptions. The authors seem to want to have things both ways — they readily acknowledge the many and important limitations of their study, but then go on to assert that “it is nevertheless instructive to predict future migrant flows for Mexico using the estimates at hand to assess the possible magnitude of climate change–related emigration.” It can’t be both — if the paper has many important limitations, then this means that that it is not particularly instructive. With respect to predicting immigration in 2080 (!), admitting limitations is no serious flaw.
To use this paper as a prediction of anything would be a mistake. It is a tentative sensitivity study of the effects of one variable on another, where the relationship between the two is itself questionable but more importantly, dependent upon many other far more important factors. The authors admit this when they write, “It is important to note that our projections should be interpreted in a ceteris paribus manner, as many other factors besides climate could potentially influence migration from Mexico to the United States.” but then right after they assert, “Our projections are informative,nevertheless, in quantifying the potential magnitude of impacts of climate change on out-migration.” It is almost as if the paper is written to be misinterpreted.
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I wonder if we’ll see this in Retraction Watch soon. It sure deserves to be retracted. This is truly junk climate science.
[UPDATE] I trust that Anthony will not object to my pointing out that I posted an extensive rebuttal of Oppenheimer’s nonsense, entitled “Border Transgressions“, no less than two years ago when it first came out in 2010. As a result, I am overjoyed that my views have been upheld. I’m also proud that WUWT, as usual, was on the case from the start.
w.
UPDATE2: Apologies to Willis for my oversight in not including his excellent essay. I believe this one was published directly prior to our change of authorship rules, and somehow I missed it. – Anthony
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The climate refugees are there, just that both the magnitude and sign of the projection are wrong. As unfounded fears of AGW cause policy changes in California and the rest of the US that have a negative economic impact, Mexicans and even retiring Americans are fleeing the US.
Kelvin Vaughan says:
July 13, 2012 at 2:18 am
Another old git. didn’t you get the memo? Rooves is so yesterday. It’s now roofs!
And now I know why you’re also a sceptic, (other than scientific,). Been there, seen it before, nothing really changed.
DaveE.
Mike Dubrasich says:
July 13, 2012 at 8:21 am
But, but, but… Mexico’s agricultural productivity has been increasing for 20 years or more, both total and per acre!
Oppy posits a cause-and-effect where the cause does not exist. We can’t say whether he’s right or not because Mex ag prod has gone up not down.
It turns out that Mexico’s ag sector is booming along quite nicely thank you…..
___________________________
Where the heck did you get that Factoid? you have no links only opinion.
…. a triumphant President Bill Clinton signed the North American Free Trade Association (NAFTA) bill into law…. stating, “I believe we have made a decision now that will permit us to create an economic order in the world that will promote more growth, more equality, better preservation of the environment, and a greater possibility of world peace.” Initially, NAFTA supporters promised a plethora of benefits for the countries of North America. American proponents promised that NAFTA would create more jobs reflecting higher wages in the United States,(1) while also reducing the U.S. trade deficit with Mexico and Canada.(2) Mexican leaders claimed that the bill had the potential to create a sizable and revitalized middle class in Mexico by raising wages and strengthening living conditions for its impoverished citizens…..
The limited benefits that have resulted from NAFTA have been overshadowed by its numerous failures, which have both negatively affected the United States and greatly harmed Mexico, especially in the agricultural sector.
Failures for the United States
…..The combination of increased imports from Mexico and a growing trade deficit have led to job losses, mostly in high-wage, non-college-educated manufacturing positions, in all 50 U.S. states and the District of Colombia.(9) When these displaced American workers later re-enter the job market, they find difficulty securing new jobs and often have to settle for markedly lower wages. As of March 2011, the United States has lost approximately 700,000 jobs due to disruptions in supply chains brought about by NAFTA.
Failures for Mexico
Although NAFTA has been detrimental for the United States, the free trade agreement has been far worse for Mexico….The poverty rate in Mexico rose from 45.6 percent in 1994 to 50.3 percent in 2000….
Perhaps the most devastating blow dealt by NAFTA to the Mexican economy was the near destruction of Mexico’s agricultural sector, in which 2 million farm workers lost their jobs and 8 million small-scale farmers were forced to sell their land at disastrously low prices, or desert it, due to sharply declining food prices.(13) Importantly, the U.S. government subsidizes many domestically produced agricultural products, allowing the products to be sold to Mexico at prices 30 percent below the cost of production.(14) Thus, after NAFTA’s inauguration, U.S. agricultural exports crowded out Mexican agriculture produce, and the United States became the main food supplier of Mexico…..
http://anacaalves.wordpress.com/2012/06/23/coha-the-failures-of-nafta/
This is one of many similar articles and studies. Catie Duckworth, Research Associate at the Council on Hemispheric Affairs leaves out one very important point.
Once the local food suppliers were driven out of business by the cheap subsidized grain the speculators et al swooped in for the kill. In 1995 the World Trade Organization Agreement on Agriculture, written by Dan Amstutz VP of Cargil a privately owned grain trader. This took the NAFTA ‘philosophy’ world wide so by 2008 we ended up with the world food crisis and food riots in over 30 countries.
How Goldman Sachs Created the Food Crisis
This has been a Win-Win-Win for everyone except the farmer and the consumer. That is the banks, speculators and middlemen have come out on top sucking the wealth out of everyone else’s pockets. American farmers were not winners either.
New Farm Bill and U.S. Trade Policy: Implications for Family Farms and Rural Communities July 27, 2002
The last time I checked the USDA statistics, average American farmer was losing $15000/year farming.
The BOTTOM LINE
Record profits for Cargill: Cargill reported record profits of $4.24 billion, beating the previous high of $3.95 billion from 2007-08, and a 63% increase of the $2.6 billion it earned last year – -Aug. 10, 2011
With fiscal year 2007 sales of $8.6 billion and net income of $993 million, Monsanto easily eclipsed last year’s record-setting sales of $7.34 billion and profit of $689 million. – October 2007
Monsanto Sees Record Sales in Fiscal Year 2008; Growth Serves as Strong Base for 2009, Monsanto increases gross profit target for 2012 to $9.5 billion to $9.75 billion
Monsanto Posts Record Q2 – April 4, 2012
April 2009: Corporations are still making a killing from hunger
The Biofuel Scam is a special case bought and paid for by ADM
ADM profits soar 550 percent as ethanol margins improve
Agribusiness giant Archer Daniels Midland Co. (ADM), the single largest beneficiary of a controversial federal ethanol tax subsidy, contributed more than $3 million in unregulated “soft money” to Republican and Democratic national party committees during the past 10 years… Dwayne O. Andreas, ADM’s former CEO was known as perhaps the top campaign contributer in the history of Congress. link
“Global Warming” has zero to do with what is happening in Agriculture. Bought and paid for politicians helping the multi-national corporate cartel corner a monopoly on food. are a heck of a lot more dangerous to the world food supply than a degree or two of warming.
Dear Gail,
Politics notwithstanding, Mexican agriculture is in FACT booming. I suggest that you consult Index Mundi, agricultural output by country, Mexico. Some commodities:
Corn 1960-2012
http://www.indexmundi.com/agriculture/?country=mx&commodity=corn&graph=production
Sorghum 1960-2012
http://www.indexmundi.com/agriculture/?country=mx&commodity=sorghum&graph=production
Soybean Meal 1964-2012
http://www.indexmundi.com/agriculture/?country=mx&commodity=soybean-meal&graph=production
Soybean Oil
http://www.indexmundi.com/agriculture/?country=mx&commodity=soybean-oil&graph=production
Swine Meat 1960-2012
http://www.indexmundi.com/agriculture/?country=mx&commodity=swine-meat&graph=production
According to the FAO, the value of Mexico’s gross ag production (compiled by multiplying gross production in physical terms by output prices at farm gate in constant dollars) increased from $8.5 billion in 1961 to a record $35.8 billion in 2010. See FAOSTAT
http://faostat.fao.org/site/613/default.aspx
My point, however, in case you missed it, is that global warming (should it occur) would benefit agriculture. The Princeton Brain Trust led by Michael Oppenheimer got it backasswards. They assumed that global warming (should it occur) would harm agriculture and cause a bunch of starving Mexicans to move north. But that’s a faulty assumption because global warming (should it occur) would increase agricultural potential.
There may be an influx of refugees from Mexico in the future. It seems there is one today. But the reasons for that influx will NOT be loss of agricultural productivity due to warmer weather, because warmer weather is GOOD for agriculture.
Is that point clear? I’m not arguing for or against NAFTA, since NAFTA had absolutely nothing to do with the post, which was about a prediction of “climate refugees” due to “reduced crop yield” due to “climate change”.
@Kim says:
July 13, 2012 at 2:19 pm
“Paging Stephen Schneider. Torment us again about advocacy and truth.”
======================
I believe all three are beyond the pale at this point, kim.
Perhaps it’s time to start calling it the “National Asylum of Science”… Don’t even have to change the initials…
Mexicans come to the USA when the economy here is good and there is bad. They come here when their politicians are doing a worse job than ours. Recently, with our economy tanked, they have been net leaving and going back to Mexico (which, I presume, means our politicians have been doing worse than theirs lately…)
Climate has nothing to do with it. Economic state does. To the extent Green Policy has been taking down economies, folks emigrate instead of immigrate.
A large part of the “Housing Boom” construction was done by Mexican labor. That pretty much left when the “Housing Bust” hit. Much tighter cause and effect.
BTW, large portions of market vegetable crops now come from Mexico as they have lower costs to produce (and as noted above, don’t have the water shut off…) The notion that some kind of crop “issue” is happening to Mexico is just daft. We do have a drought / heat wave in the U.S. Cornbelt that is driving up corn and soybean prices (and pushing yields way down). Rather similar to the 1930’s era, though not as bad.
IMHO, that is due to the lower UV and resultant less tall air column causing faster wind speeds (moving mass in a lower total height) and a “loopy jet stream” as the tropical heat gets dumped and the polar temps plunge. (The descending polar vortex is colder). So we’ve got record cold in Alaska and on the West Coast it’s back to the 1960’s cool weather; however hot Mexican desert air gets pulled up over Texas and out into the central USA as it heads poleward to dump its heat.
So if anything, I’d expect to see better production out of Mexico ( less heat, more moisture in the dry areas as ocean air gets pulled more inland) as we take a hit from the dry air. Typical “loopy jet stream” patterns, IMHO. (Though I think Anthony could likely do a much better job of sorting that out. I’m just speculating from memories of prior decades.)
So much of “Climate Science” seems to be just writing Science Fiction and putting footnotes in it…
I see no reason to expect crop failures in Mexico, unless as a result of bad government, which is the major problem everywhere. What is interesting is why Oppenheimer et. al. think we (in the U.S.) should care if crop failures do happen: not because they would mean less food, coffee, and cotton for us, too (which they would); and certainly not because of compassion. No, the thing we should worry about is 6.7 million (an interestingly exact figure) Mexicans emigrating to the U.S. over a period of 68 years. I confess I do not see that as a problem, at least for the U.S..
Let me deconstruct for you. Oppenheimer is an urban white liberal Ivy League college professor. He is using the implied threat of illegal immigration to bait conservatives (or whomever fears illegal immigration) into a climate alarmism stance.
Many here have taken that bait. But the real underlying issue is climate alarmism.
The funny thing is, if the climate changes toward warmer, it will be a BOON TO MANKIND as well as other lifeforms.
The current corn crop in Ohio is expected to be poor, due to drought not heat. However, it may rain this week and the panic will subside. The current corn crop in other mid-Western states is doing fine.
Drought is NOT a feature of global warming. The warmer it gets, the more it rains. Drought is a feature of global COOLING.
If the Earth were to warm, that would cause more evaporation from the 5/6ths of the Earth’s surface that is water. Water vapor would increase, as would clouds. More rain would fall on the 1/6th of the Earth’s surface that is land.
During the Holocene Climatic Optimum many modern deserts were green. It was warmer then, and there was more rainfall. Conversely, during glacial periods there was widespread drought because much water was locked up in continental icesheets and there was less evaporation from the oceans.
Warmer means wetter not dryer. That is a key point that many people get wrong. They conflate warmer with drought. That’s 180° reversed from the actual empirical evidence.
Now, you may not believe the Earth is getting appreciably warmer. I don’t. But if it were, that would cause more rainfall, longer growing seasons, and more agricultural potential.
The hole in Oppenheimer’s argument is not the complexity of migration factors but rather the failure to understand that Warmer Is Better for agriculture. His race baiting is a red herring.
Pamela Gray says:
July 13, 2012 at 7:28 am
If you do not realize the education system has been infiltrated and now controlled by the left (particularly Uni’s), you are as much a part of the problem as anyone. Climate science corruption is just the tip of the iceberg.
It is also funny that you cannot address your post to me as it was clearly intended to be. The weak and cowardly way a teacher reacts to a student who is brighter and funnier than they are. Had plenty that were insecure like you.
Just out of curiosity, what drives the El Nino Southern Oscillation? Why 5 years?
Anyone?
Why was my post deleted? She gets to post such garbage, and I call her on her crap, I get deleted? What gives?
There it is. That was weird.
David Ball,
I really don’t see anything objectionable in Pamela Gray’s comment. What, exactly, are you referring to?
“The current school system has nothing to do with it.”
I will leave it at that for now.
Are there any universities left where it’s safe to send my kids? I’m sick and tired of reading about these jokers who push junk science.
“””””…..Beale says:
July 14, 2012 at 8:30 am
I see no reason to expect crop failures in Mexico, unless as a result of bad government, which is the major problem everywhere. What is interesting is why Oppenheimer et. al. think we (in the U.S.) should care if crop failures do happen: not because they would mean less food, coffee, and cotton for us, too (which they would); and certainly not because of compassion. No, the thing we should worry about is 6.7 million (an interestingly exact figure) Mexicans emigrating to the U.S. over a period of 68 years. I confess I do not see that as a problem, at least for the U.S…..”””””
Well there certainly isn’t a problem (as far as I am concerned) with people emigrating to the USA from anywhere in the known universe, or even any of the parallel universes; I did so myself many years ago.
There is a problem (for the USA) with the US being invaded from anywhere else. So much so, that the US Constitution declares that the USA “shall protect each of them ( the 57 States of the USA) from invasion.” It’s one of the few situations in that Constitution that tells the Government that they MUST do something; rather than they are permitted (the Congress) to do it, as in Article I, section 8.
People who emigrate to the USA; or anywhere else I know of, generally have papers issued by the country they emigrate to.