Category Archives: Climate Change

”Global Warming ‘Hiatus’ Never Happened”


About that supposed pause in global warming:

Global warming ‘hiatus’ never happened, Stanford scientists say: An apparent lull in the recent rate of global warming that has been widely accepted as fact is actually an artifact arising from faulty statistical methods, Stanford scientists say. …The finding calls into question the idea that global warming “stalled” or “paused” during the period between 1998 and 2013. …

Using a novel statistical framework that was developed specifically for studying geophysical processes such as global temperature fluctuations, Rajaratnam and his team of Stanford collaborators have shown that the hiatus never happened.

“Our results clearly show that, in terms of the statistics of the long-term global temperature data, there never was a hiatus, a pause or a slowdown in global warming,” said Noah Diffenbaugh, a climate scientist in the School of Earth, Energy & Environmental Sciences, and a co-author of the study.

Faulty ocean buoys

The Stanford group’s findings are the latest in a growing series of papers to cast doubt on the existence of a hiatus. …

The Stanford scientists say their findings should go a long way toward restoring confidence in the basic science and climate computer models that form the foundation for climate change predictions.

“Global warming is like other noisy systems that fluctuate wildly but still follow a trend,” Diffenbaugh said. “Think of the U.S. stock market: There have been bull markets and bear markets, but overall it has grown a lot over the past century. What is clear from analyzing the long-term data in a rigorous statistical framework is that, even though climate varies from year-to-year and decade-to-decade, global temperature has increased in the long term, and the recent period does not stand out as being abnormal.”

[I omitted the detailed discussion of the research.]

”Global Warming ‘Hiatus’ Never Happened”
Mark Thoma
Thu, 17 Sep 2015 16:49:22 GMT

IER Comment on the “Social Cost of Carbon”

It is getting warmer.

The consequence of that and the value of the cost we should bear to reduce the warming are very open questions as far as I can tell.

If you are a true nerd about the global warming stuff, you should definitely get a cup of coffee some morning and spend a half hour carefully reading the Institute for Energy Research (IER) formal “comment” (submitted to the government) on the Social Cost of Carbon. However, if you have a shorter attention span, in two blog posts at IER I will summarize our key arguments.

Here’s the first post. An excerpt:

On the theoretical front, our main theme is that the “social cost of carbon” is not an objective fact of the world, analogous to the charge on an electron or the boiling point of water. Many analysts and policymakers refer to the “science being settled” and so forth, giving the impression that the SCC is a number that is “out there” in Nature, waiting to be measured by guys in white lab coats.

On the contrary, by its very nature the SCC is an arbitrary number, which is completely malleable in the hands of an analyst who can make it very high, very low, or even negative, simply by adjusting parameters. Precisely because the SCC even at a conceptual level is so vulnerable to manipulation in this fashion, the analysts giving wildly different estimates are not “lying.” As we will see, the estimates of the SCC in the peer-reviewed literature are all over the map, demonstrating that this is hardly a feature of the “outside world.”

IER Comment on the “Social Cost of Carbon”
Bob Murphy
Tue, 11 Mar 2014 21:29:17 GMT

Iceland in the Year 2050

That’s there’s climate changes seems clear, but its implications are less so.

The NY Times reports a type of James Bond story as a mysterious Chinese zillionaire seeks to purchase a large amount of rural Iceland to erect a snowy golf course.   Do you smell Dr. No?  I don’t.  I see a climate change adaptation bet.   Arbitrage is to buy low and sell high.  Perhaps because he read Climatopolis, Huang Nubo is making an investment that could earn a high return if Iceland’s quality of life improves relative to the rest of the world as climate change plays out.    New challenges create new opportunities.  While the NY Times views this story as just “weird”, I think it is a nice example of how those who form expectations of the future act upon those expectations.  Mr. Nubo could lose on this investment but he is experimenting and there are plausible scenarios under which he will become even richer. 
It is certainly possible that his “golf course” is an attempt by China to claim property rights to minerals that might be under the ground but any land owner always has this option.  I ask my students to solve for a price of gasoline such that Beverly Hills home owners would knock down their homes and drill for gas underneath the surface.  

Iceland in the Year 2050
Matthew Kahn
Sat, 23 Mar 2013 16:20:00 GMT

Climate Change


Recent studies add to the evidence that we are changing the world:



If you want to see what “climate change” really means, as in what will be changing where, check out the 2013 National Climate Assessment report. It’s fantastic, and chuck full of visualizations:


One side effect: More shipping in the Arctic:


Climate Change
Wed, 13 Mar 2013 19:37:39 GMT

2012 Shatters the US Temperature Record. Fox, Watts, and Spencer Respond by Denying Reality


The National Oceanic and Atmospheric Administration’s National Climatic Data Center (NCDC) recently announced that 2012 broke the record for the hottest average annual surface temperature for the contiguous United States by a wide margin – a full degree Fahrenheit (Figure 1).  Given that this is a very inconvenient fact for certain groups, we should perhaps not be surprised that the NCDC has come under attack for reporting this year’s record.

Most prominently, Fox News ran a story quoting Roy Spencer (a contrarian climate scientist at the University of Alabama at Huntsville [UAH]), Anthony Watts (a blogger and meteorologist), and Steven Goddard (a pseudonym for a climate blogger who goes to the extreme in denying human-caused global warming), all of whom directly or indirectly accused the NCDC of somehow fudging the data to introduce a false warming trend and make 2012 the record hottest year.

The biggest irony of all is that 2012 is the hottest year on record for the USA in Spencer’s own UAH lower atmosphere temperature dataset, and yet just a week after this announcement he accused NCDC of improper adjustments when their results matched his own.  Without those adjustments, the NCDC record would not match Spencer’s UAH dataset nearly as closely.  The UAH continental USA warming trend from 1979 to 2012 is 0.24°C per decade, while the trend in maximum daily unadjusted NCDC data over the same timeframe is just 0.11°C per decade.  Once the adjustments Spencer criticizes are implemented, the NCDC trend becomes much closer to the UAH trend, at 0.21°C per decade (Figure 1).

uah vs. ncdc

Figure 1: UAH continental USA lower troposphere temperature product (version 5.5; blue) vs. NCDC continental USA maximum daily surface temperature unadjusted (black) and adjusted (version 2.5; red), with linear trends from 1979 to 2012 (dashed).

Another major irony is that while these contrarians treat "adjustment" as a bad word, in their own scientific research they admit that such adjustments are actually very important, and Roy Spencer frequently makes similar adjustments to his own UAH temperature dataset.

These are the latest in a long line of efforts by climate contrarians to cast doubt on the accuracy of the instrumental temperature record, because if the temperature record is wrong, then poof – no more global warming to worry about.  If only life were so simple.

How We Know the Temperature Record is Accurate

The accuracy of the instrumental surface temperature record, which is compiled from thousands of thermometers in temperature stations around the country and the planet, has been confirmed time and time again by a number of scientific studies using a variety of different approaches.  Individuals have taken a do-it-yourself approach, comparing the raw, unadjusted temperature data to the final products from NCDC and other scientific organizations (Figure 2).  Skeptical Science’s Kevin C put together a do-it-yourself tool so that anybody can try this at home.

Figure 2: Comparison of land-only surface temperature reconstructions, 1900–2009

People have also compared the raw to the adjusted data and found that the adjustments don’t make a very big difference in the final temperature record product (Figure 3).

Figure 3: Comparison of global temperatures from raw (dark green) and adjusted (light green) Global Historical Climatology Network (GHCN) v3 data, 1880–2010 (analysis by Zeke Hausfather).

The Koch-funded Berkeley Earth Temperature Station (BEST) project also set out to test the surface temperature record accuracy by creating their own record using a novel and robust methodology (described in detail by Rohde et al.), and arrived at essentially the same result as NCDC (Figure 4).


Figure 4: Land temperature with 1- and 10-year running averages. The shaded regions are the one- and two-standard deviation uncertainties calculated including both statistical and spatial sampling errors. Prior land results from the other groups are also plotted, including NCDC in green.

Measurements made by satellites of the temperature of the lower atmosphere (the lower troposphere, or LT), including by Spencer’s UAH group, are also very consistent with the measurements made by thermometers on the ground (Figure 5).

Figure 5: Comparison of temperatures from surface stations and satellite monitoring of the lower troposphere (LT).

The NCDC temperature record has been compared to a number of reanalysis products (climate or weather model simulations of the past that include data assimilation of historical observations) by Vose et al. (2012), which also confirmed its accuracy, concluding,

"For the conterminous United States, the trend in the adjusted [U.S. Historical Climatology Network] (0.327°C/decade) is generally comparable to the ensemble mean of the reanalyses (0.342°C/decade). It is also well within the range of the reanalysis trend estimates (0.280 to 0.437° C/decade)."

A paper by Anderson et al. (2012) also created a new global surface temperature record reconstruction using 173 records with some type of physical or biological link to global surface temperatures (corals, ice cores, speleothems, lake and ocean sediments, and historical documents).  The study compared their reconstruction to the NCDC instrumental temperature record and found a strong correlation between the two, of 0.76 (Figure 6).

Fig 1

Figure 6: Anderson et al. (2012) Paleo Index (solid) and the merged land-ocean surface temperature anomalies (MLOST, dashed) relative to 1901-2000.

And of course natural thermometers clearly confirm the Earth’s general warming trend – vanishing ice, rising oceans, species migrations, earlier arrival of spring, etc.

From these results, it’s quite clear that NCDC is not introducing a fake warming trend.  So where does this myth come from?

Critical Data Adjustments

There are a number of adjustments that scientific groups like NCDC have to make to the raw temperature data.  For example, sometimes a temperature station will move, or the time of observation of the thermometer will change, or the type of temperature station will change.  These changes can introduce biases into the instrumental record which are not representative of actual temperature changes, so they must be accounted for and removed in order to get an accurate measurement of actual surface temperature changes.  For further details, see this post and Glenn Tamblyn’s excellent four-part series on the surface temperature record.

Coincidentally, a number of these factors have introduced a cooling bias into the surface temperature record in recent decades, and NCDC removes this cool bias with its adjustment methodology.  Certain individuals who want to deny that global warming is happening mischaracterize this removal of cool biases, claiming NCDC is introducing a false warming trend.

In reality the adjustments made by NCDC are based on sound science, and detailed in the peer-reviewed scientific literaure.  Their version 2 temperature dataset and processing steps are described in detail in Menne et al. (2009) and on the NCDC website, and details regarding some recent and relatively small revisions for version 2.5 of their dataset are described in two technical reports (Williams et al. 2012a and 2012b) and on the same NCDC website.

The general effectiveness of these adjustments has been confirmed by Peterson et al. (2003), Menne et al. (2010), and Fall et al. (2011).  Another paper currently in press, Hausfather et al. (2012), found that the NCDC adjustments are critical in removing the influence of artificial artificial heat sources on the thermometers (the urban heat island effect).

"…urbanization accounts for 14% to 21% of the rise in unadjusted minimum temperatures since 1895 and 6% to 9% since 1960. The USHCN-Version 2 homogenization process effectively removes this urban signal such that it becomes insignificant during the last 50-80 years."

In short, the adjustments made by NCDC to the raw temperature data are scientifically justified, very important, supported in the scientific literature, and their effectiveness has been confirmed by a wide variety of different approaches.

Watts’ False Accusations Ignite the Myth

The specific accusations about NCDC falsifying data to make 2012 the hottest year on record in the USA originated on Anthony Watts’ blog, where after finding discrepancies between temperatures listed in NCDC’s past monthly State of the Climate reports, and those in its climate database.  Watts immediately accused NCDC of "keep[ing] two separate sets of climate books for the USA", rather than simply contacting them to ask for an explanation.

That’s what I did, and NCDC provided the following response, explaining that the discrepancy was due to the recent switch from version 2 to version 2.5 of their methodology in October 2012 (as discussed above):

It is totally inappropriate to mix values from different data bases to identify records.  This is exactly what Anthony Watts has done.  He selected the mean monthly temperatures from an older data base (version 2 USHCN) and compared it to mean monthly temperatures in a newer data base (version 2.5 USHCN).  This is a fatal error.  For example, the US average temperature of July  2012 is the record warmest within both data bases.  Values in version 2.5 are different from version 2.0 for two reasons.  Different base periods are used in the two data bases to compute normals, which affect the monthly mean temperatures for all years.  Second, an improved correction algorithm has been applied to the newer data base.  NCDC has notified users on our web site back in September of 2012 of the differences in the two data sets.  All of NOAA NCDC analyses are based on peer-reviewed published work.  Please see for more details.

Contrarian Contradictions
Spencer’s Own Adjustments

Ironically, Roy Spencer’s own UAH temperature record adjustment methodology has undergone a large number of major revisions:

UAH corrections

Major corrections to the UAH temperature trend over the years.

There is of course nothing wrong with making these adjustments; quite the contrary.  Science advances, we learn, and we improve our understanding and methods.  But for Spencer to criticize NCDC for making the same sorts of scientifically justified adjustments is hypocritical and self-contradictory.

spencer v spencer

image created by John Cook
Watts’ Criminal Accusations

For his part, Anthony Watts suggested to Fox that NCDC’s adjustments are essentially criminal, even though he was a co-author on the Fall et al. (2011) paper which confirmed the general accuracy of the instrumental surface temperature record, and noted that the types of adjustments made by NCDC are necessary.

watts vs. watts

image created by John Cook

In both cases it would be hard to understand how these contradictory statements could come from the same person, except such contradictory arguments are the norm for climate contrarians.

Temperature Record is Reliable When Convenient

Additionally, the last mainstream media climate myth we addressed just last week incorrectly claimed that global warming has ‘stalled’, based almost exclusively on the instrumental surface temperature record (and a climate model run, which contrarians also claim are unreliable).  Now contrarians are arguing that the temperature record is unreliable.  Which is it?  The instrumental temperature record can’t be both the basis of an argument one week and completely unreliable the next week.

Yes, 2012 Was the Hottest Year on Record in the USA

To sum up,

  • The accuracy of the surface temperature record has been confirmed time and time again by a wide variety of methods, including comparisons with do-it-yourself temperature analyses, with satellite measurements, and with natural thermometers.
  • Scientific groups like NCDC make necessary, scientifically-justified adjustments to the raw data in order to remove biases introduced by factors like changes in temperature station locations, time of observations, and types of instrumentation. 
  • These adjustments are published in the peer-reviewed scientific literature, and their effectiveness has been confirmed by numerous peer-reviewed studies.
  • Spencer’s own UAH group has made many revisions to its own data adjustment methodology as well.
  • If climate contrarians dispute the validity of any of the adjustments made by NCDC, they should subject their criticisms to the scientific peer-review process rather than making unsubstantiated and unjustified accusations of malfeasance in the mainstream media.
  • The contrarians making these accusations are contradicting their own results and previous research, which support the effectiveness and importance of the adjustments made by NCDC.

Overall, the contrarians have given us no reason to doubt the accuracy of the instrumental surface temperature record or the fact that 2012 was the hottest year on record in the continental United States.  In fact, this result is consistent with Roy Spencer’s own UAH dataset.  We are instead left with just another mainstream media article full of denial, unsubstantiated assertions, contradictions, and conspiracy theories, misinforming the general public, and delaying our efforts to actually solve the climate problem by denying the reality that it exists and is a grave threat.

Also see this excellent post on the subject by Josh Timmer at Ars Technica.

2012 Shatters the US Temperature Record. Fox, Watts, and Spencer Respond by Denying Reality
Tue, 15 Jan 2013 02:37:08 GMT

Environmentalism and the environment

There is no point per the author.

The Economist has an interesting article on the gas boom in America:

Gas has wrought some remarkable changes. Over the past five years America has recorded a decline in greenhouse-gas emissions of 450m tonnes, the biggest anywhere in the world. Ironically, given its far greater effort to tackle climate change, the European Union has seen its emissions rise, partly because its higher gas prices (linked to oil) have led to an increase in coal-fired power generation.

So let’s review the facts:

1.  America is reducing greenhouse gas emissions faster than anywhere else because Bush/Cheney ignored environmentalists and went with the “drill baby drill” strategy.

2.  Europe is switching to coal because gas is too expensive.  But wait; doesn’t Europe also have lots of shale gas? They do. But they listened to the environmentalists, and have all but banned fracking.

3.  But wait; doesn’t Europe have lots of carbon-free nuclear power plants?  Yes, but countries like Germany have decide to close them all down, on the recommendation of environmentalists.  Other countries are also leaning that way.  I can sort of understand Japan, but when was the last time you heard about an earthquake in Germany or Sweden?

Now it’s true that the US still has a worse record than Europe, especially in high energy consuming states like Texas.  But the same issue of The Economist has another article with this interesting tidbit:

At a casual glance, Houston looks much as it ever did: a tangle of freeways running through a hodgepodge of skyscrapers, strip malls and mixed districts. A closer inspection, though, shows signs of change. The transport authority, which branched into light rail in 2004, is now planning three new lines, adding more than 20 miles of track. Most of the traffic lights now boast LED bulbs, rather than the incandescent sort. More than half the cars in the official city fleet are hybrid or electric, and in May a bike-sharing programme began. Every Wednesday a farmers’ market takes place by the steps of city hall.

Other changes are harder to see. The energy codes for buildings have been overhauled and the city is, astonishingly, America’s biggest municipal buyer of renewable energy; about a third of its power comes from Texan wind farms.

But are windmills actually that good for the environment?  Still another article in the same issue has this to say:

By 2009 Inner Mongolia had become China’s largest producer of coal. It is the biggest source of the world’s supply of rare earths. The coal bed around Xilinhot, the capital of Xilin Gol, boasts 38% of global reserves of germanium, a rare earth used in the making of circuitry for solar cells and wind turbines. Ripping up the grasslands and sucking up scarce water for thirsty mines has been part of the price of these “green energy” products.

Here are some comparisons between Inner Mongolia and Texas:

Texas is a state with 25.7 million people.  It started out as a ranching state and is now dominated by energy production.  It’s mostly hot and flat, and is growing much faster than the rest of the US.

Inner Mongolia is a province with 24.7 million people.  It started out as a herding state and is now dominated by energy production.  It’s mostly hot and flat, and is growing much faster than the rest of China.

Much faster?  How’s that possible given that China has grown at 10% per year for decades?  Because Inner Mongolia has grown at 17% per year since 2001.  Even Texans can’t say that.

PS.  People trying to convince you that China’s a bubble often show a video of Ordos, the almost uninhabited new city.  Ordos is in Inner Mongolia, and is hosting the Miss World pageant next month.  Let’s see what Ordos looks like in 10 years before we jump to conclusions.

PPS.  Do you recall that America’s had two Presidents named Bush, the second of which was governor of Texas?  China’s current President is named Hu, and another Hu is being touted as a possible future president.  He’s now the governor of Inner Mongolia.

PPPS.  Think about Mercedes, BMW and Audi.  Then think about the quality of the stuff you buy that’s made in China.  Do you sleep better at night knowing that Germany is shutting down its entire nuclear industry, and China is building nuclear plants at a rapid pace.

PPPPS.  Please don’t ask me what the point of this post is.  It’s Sunday. There is no point.

Environmentalism and the environment
Sun, 22 Jul 2012 21:03:39 GMT

Doom and Gloom maybe not, but a blow to our spirit

A new study has come out as they do maybe every decade or so that we are killing the earth.  The club or Rome in the 70’s said we’d run out of every thing by now, and the world would be worse now.

I think humanity will survive we’ll adapt.  The following elaborates pretty well why; but is that all we want to do?

Nature (an academic journal) is grabbing headlines with a new “big think” piece.  Here is a quote from the LA Times
“A group of international scientists is sounding a global alarm, warning that population growth, climate change and environmental destruction are pushing Earth toward calamitous — and irreversible — biological changes.
In a paper published in Thursday’s edition of the journalNature, 22 researchers from a variety of fields liken the human impact to global events eons ago that caused mass extinctions, permanently altering Earth’s biosphere.
“Humans are now forcing another such transition, with the potential to transform Earth rapidly and irreversibly into a state unknown in human experience,” wrote the authors, who are from the U.S., Europe, Canada and South America.”
These scientists could certainly be right about their predictions about global climate patterns but how do they know that we (both people and creatures) have such limited ability to adapt to the “new normal”?   I don’t see any social scientists involved in this project.   I would like to see these 22 researchers tell a convincing story for how the trends they highlight will decimate our world and that we will be defenseless to protect ourselves in the face of this change.
I would like to see these “crystal ball” researchers explain in nitty/gritty details the “calamitous” scenarios they envision for us and creatures.  If they foresee this tragedy, are there really no pathways to adapt? 
To quote these guys again,
“The swiftness of climate change is likely to outpace the ability of species to adapt, especially as natural habitat becomes more fragmented, Barnosky said.
All this could produce a biologically impoverished Earth that would rob humans of vital ecological services such as insects that pollinate crops, forests that provide clean water, and tropical species that are the source of new drugs.
“We have created a bubble of human population and economy … that is totally unsustainable and is either going to have to deflate gradually or is going to burst,” said co-author James Brown, a distinguished professor of biology at the University of New Mexico. “If it’s going to burst, the consequences are really going to be grim for people as well as biodiversity and the rest of the planet.”
So, take a look at the middle paragraph. If we anticipate that Mother Nature won’t be providing these services anymore, isn’t there a profit opportunity for innovators who can deliver a substitute?
I disagree with Prof. James Brown.  He needs to take a class in econ 101 at the Economics Department at UNM.   Capitalism will be the solution here not the problem.

Doom and Gloom and the Absence of Social Scientists
Matthew E. Kahn
Fri, 08 Jun 2012 22:41:00 GMT

I think we can likely get by with less biodiversity, but you can live without a lot of things, you just might not want to.

The diversity of life on this planet makes it a lovely place.  Maybe it reminds that we are just one species.  Maybe it reminds us to be humble and that we are gifted with out existence by God.  If we as humans come to be kings of a domain with few any subject left, I think we’ll regret that.