Tag: climate change

Is There No “Hiatus” in Global Warming After All?

A new paper posted today on ScienceXpress (from Science magazine), by Thomas Karl, Director of NOAA’s Climate Data Center, and several co-authors[1], that seeks to disprove the “hiatus” in global warming prompts many serious scientific questions.

The main claim[2] by the authors that they have uncovered a significant recent warming trend is dubious. The significance level they report on their findings (.10) is hardly normative, and the use of it should prompt members of the scientific community to question the reasoning behind the use of such a lax standard.

In addition, the authors’ treatment of buoy sea-surface temperature (SST) data was guaranteed to create a warming trend. The data were adjusted upward by 0.12°C to make them “homogeneous” with the longer-running temperature records taken from engine intake channels in marine vessels. 

As has been acknowledged by numerous scientists, the engine intake data are clearly contaminated by heat conduction from the engine itself, and as such, never intended for scientific use. On the other hand, environmental monitoring is the specific purpose of the buoys. Adjusting good data upward to match bad data seems questionable, and the fact that the buoy network becomes increasingly dense in the last two decades means that this adjustment must put a warming trend in the data.

The extension of high-latitude arctic land data over the Arctic Ocean is also questionable. Much of the Arctic Ocean is ice-covered even in high summer, meaning the surface temperature must remain near freezing. Extending land data out into the ocean will obviously induce substantially exaggerated temperatures.

Additionally, there exist multiple measures of bulk lower atmosphere temperature independent from surface measurements which indicate the existence of a “hiatus”[3]. If the Karl et al., result were in fact robust, it could only mean that the disparity between surface and mid-tropospheric temperatures is even larger that previously noted. 

Getting the vertical distribution of temperature wrong invalidates virtually every forecast of sensible weather made by a climate model, as much of that weather (including rainfall) is determined in large part by the vertical structure of the atmosphere.

Instead, it would seem more logical to seriously question the Karl et al. result in light of the fact that, compared to those bulk temperatures, it is an outlier, showing a recent warming trend that is not in line with these other global records.

And finally, even presuming all the adjustments applied by the authors ultimately prove to be accurate, the temperature trend reported during the “hiatus” period (1998-2014), remains significantly below (using Karl et al.’s measure of significance) the mean trend projected by the collection of climate models used in the most recent report from the United Nation’s Intergovernmental Panel on Climate Change (IPCC). 

It is important to recognize that the central issue of human-caused climate change is not a question of whether it is warming or not, but rather a question of how much. And to this relevant question, the answer has been, and remains, that the warming is taking place at a much slower rate than is being projected.

The distribution of trends of the projected global average surface temperature for the period 1998-2014 from 108 climate model runs used in the latest report of the U.N.’s Intergovernmental Panel on Climate Change (IPCC)(blue bars). The models were run with historical climate forcings through 2005 and extended to 2014 with the RCP4.5 emissions scenario. The surface temperature trend over the same period, as reported by Karl et al. (2015, is included in red. It falls at the 2.4th percentile of the model distribution and indicates a value that is (statistically) significantly below the model mean projection.

The distribution of trends of the projected global average surface temperature for the period 1998-2014 from 108 climate model runs used in the latest report of the U.N.’s Intergovernmental Panel on Climate Change (IPCC)(blue bars). The models were run with historical climate forcings through 2005 and extended to 2014 with the RCP4.5 emissions scenario. The surface temperature trend over the same period, as reported by Karl et al. (2015, is included in red. It falls at the 2.4th percentile of the model distribution and indicates a value that is (statistically) significantly below the model mean projection.

[1] Karl, T. R., et al., Possible artifacts of data biases in the recent global surface warming hiatus. Scienceexpress, embargoed until 1400 EDT June 4, 2015.

[2] “It is also noteworthy that the new global trends are statistically significant and positive at the 0.10 significance level for 1998-2012…”

[3] Both the UAH and RSS satellite records are now in their 21st year without a significant trend, for example

You Ought to Have a Look: Climate Change Subtleties, Hurricanes, and Chocolate Bunnies

You Ought to Have a Look is a feature from the Center for the Study of Science posted by Patrick J. Michaels and Paul C. (“Chip”) Knappenberger.  While this section will feature all of the areas of interest that we are emphasizing, the prominence of the climate issue is driving a tremendous amount of web traffic.  Here we post a few of the best in recent days, along with our color commentary.

We highlight a couple of headlines this week that made us chuckle a bit, although what they portend is far from funny.

The first was from the always amusing “Energy and Environment” section of the Washington Post. Climate change beat writer Chris Mooney penned a piece headlined “The subtle — but real — relationship between global warming and extreme weather events” that was a hit-you-over-the-head piece about how human-caused global warming could be linked to various weather disasters of the past week, including the floods in Houston, the heatwave in India and hurricanes in general.

Mooney starts out, lamenting:

Last week, some people got really mad at Bill Nye the Science Guy. How come? Because he had the gall to say this on Twitter:

Billion$$ in damage in Texas & Oklahoma. Still no weather-caster may utter the phrase Climate Change.

Nye’s comments, and the reaction to them, raise a perennial issue: How do we accurately parse the relationship between climate change and extreme weather events, as they occur in real time?

It’s a particularly pressing question of late, following not only catastrophic floods in Texas and Oklahoma, but also a historic heatwave in India that has killed over 2,000 people so far, and President Obama’s recent trip to the National Hurricane Center in Miami, where he explicitly invoked the idea that global warming will make these storms worse (which also drew criticism).

As the Nye case indicates, there is still a lot of pushback whenever anyone dares to link climate change to extreme weather events. But we don’t have to be afraid to talk about this relationship. We merely have to be scrupulously accurate in doing so, and let scientists lead the way.

The Spin Cycle: Accelerating Sea Level Rise

The Spin Cycle is a reoccurring feature based upon just how much the latest weather or climate story, policy pronouncement, or simply poo-bah blather spins the truth. Statements are given a rating between 1-5 spin cycles, with less cycles meaning less spin. For a more in-depth description, visit the inaugural edition.

A popular media story of the week was that sea level rise was accelerating and that this was worse than we thought. The stories were based on a new paper published in the journal Nature Climate Change by an author team led by the University of Tasmania’s Christopher Watson.

Watson and colleagues re-examined the satellite-based observations of sea level rise (available since the early 1990s) using a new methodology that supposedly better accounts for changes in the orbital altitude of the satellites—obviously a key factor when assessing sea levels by determining the height difference between the ocean’s surface and the satellites, the basic idea behind altimetry-based sea level measurements.

So far so good.

Their research produced two major findings, 1) their new adjusted measurements produced a lower rate of sea level rise than the old measurements (for the period 1993 to mid-2014), but 2) the rate of sea level rise was accelerating.

It was the latter that got all of the press.

But, it turns out, that in neither case, were the findings statistically significant at even the most basic levels used in scientific studies. Generally speaking, scientists report a findings as being “significant” if there is a less than 1-in-20 chance that the same result could have been produced by random (i.e., unexplained) processes. In some fields, the bar is set even higher (like 1 in 3.5 million). We can’t think of any scientific field that accepts a lower than a 1-in-20 threshold (although occasional individual papers do try to get away with applying a slightly lower standard).

Climate Change Concerns Don’t Belong in Dietary Guidelines

On Friday, May 8, the public comment period closed for the new 2015 Dietary Guidelines issued by the U.S. Department of Agriculture (USDA) and the Department of Health and Human Services (HHS). In a nutshell, the new dietary guidelines are to eat a diet richer in plant-based foods and leaner in animal-based products. One of the considerations used by the USDA/HHA in their Scientific Report used to rationalize these new dietary guidelines was that such diets are

“associated with more favorable environmental outcomes (lower greenhouse gas emissions and more favorable land, water, and energy use) than are current U.S. dietary patterns.” [emphasis added]

Throughout the Scientific Report whenever greenhouse gases are mentioned, a negative connotation is attached and food choices are praised if they lead to reduced emissions.

This is misleading on two fronts. First, the dominant greenhouse gas emitted by human activities is carbon dioxide which is a plant fertilizer whose increasing atmospheric concentrations have led to more productive plants, increasing total crop yields by some 10-15 percent to date. The USDA/HHS is at odds with itself in casting a positive light on actions that are geared towards lessening a beneficial outcome for plants, while at the same time espousing a more plant-based diet.

And second, the impact that food choices have on greenhouse gas emissions is vanishingly small—especially when cast in terms of climate change. And yet it is in this context that the discussion of GHGs is included in the Scientific Report. The USDA/HHS elevates the import of GHG emissions as a consideration in dietary choice far and above the level of its actual impact.

In our Comment to the USDA/HHS, we attempted to set them straight on these issues.

Our full Comment is available here, but for those looking for a synopsis, here is the abstract:

There are really only two reasons to discuss greenhouse gas emissions (primarily carbon dioxide) in the context of dietary guidelines in the U.S., and yet the USDA and HHS did neither in their Scientific Report of the 2015 Dietary Guidelines Advisory Committee (DGAC).

The first reason would be to discuss how the rising atmospheric concentration of CO2—a result primarily of the burning of fossil fuels to produce energy—is a growing benefit to plant life. This is an appropriate discussion in a dietary context as atmospheric CO2 is a fertilizer that promotes healthier, more productive plants, including crops used directly as food for humans or indirectly as animal feed. It has been estimated that from the atmospheric CO2 enrichment to date, total crop production as increased by 10-15 percent. This is a positive and beneficial outcome and one that most certainly should be included in any discussion of the role of greenhouse gases emissions in diet and nutrition—but is inexplicably lacking from such discussion in the DGAC report.

The second reason to discuss greenhouse gas emissions in a diet and nutrition report would be to dispel the notion that through your choice of food you can “do something” about climate change.  In this context, it would be appropriate to provide a quantitative example of how the dietary changes recommended by the DGAC would potentially impact projections of the future course of the climate. Again, the DGAC failed to do this.  We help fill this oversight with straightforward calculation of averted global warming that assumes all Americans cut meat out of their diet and become vegetarians—an action that, according to the studies cited by the DGAC, would have the maximum possible impact on reducing greenhouse gas emissions and thus mitigating future climate change.  Even assuming such an unlikely occurrence, the amount of global warming that would be averted works out to 0.01°C (one hundredth of a degree) by the end of the 21st century.  Such an inconsequential outcome has no tangible implications.  This should be expressed by the DGAC and mention of making dietary changes in the name of climate change must be summarily deleted.

We recommend that if the DGAC insists on including a discussion of greenhouse gas emissions (and thus climate change) in it 2015 Dietary Guidelines, that the current discussion be supplemented, or preferably replaced, with a more accurate and applicable one—one that indicates that carbon dioxide has widespread and near-universal positive benefits on the supply of food we eat, and that attempting to limit future climate change through dietary choice is misguided and unproductive.  These changes must be made prior to the issuance of the final guidelines. 

We can only guess on what sort of impact our Comment will have, but we can at least say we tried.

You Ought to Have a Look: Science Round Up—Less Warming, Little Ice Melt, Lack of Imagination

You Ought to Have a Look is a feature from the Center for the Study of Science posted by Patrick J. Michaels and Paul C. (“Chip”) Knappenberger. While this section will feature all of the areas of interest that we are emphasizing, the prominence of the climate issue is driving a tremendous amount of web traffic. Here we post a few of the best in recent days, along with our color commentary.

As Pope Francis, this week, focused on examining the moral issues of climate change (and largely ignoring the bigger moral issues that accompany fossil fuel restrictions), he pretty much took as a given that climate change is “a scientific reality” that requires “decisive mitigation.” Concurrently, unfolding scientific events during the week were revealing a different story.

First and foremost, Roy Spencer, John Christy and William Braswell of the University of Alabama-Huntsville (UAH)—developers and curators of the original satellite-derived compilation of the temperature history of the earth’s atmosphere—released a new and improved version of their iconic data set. Bottom line: the temperature trend in the lower atmosphere from the start of the data (1979) through the present came in as 0.114°C/decade (compared with 0.14°C in the previous data version). The new warming trend is less than half what climate models run with increasing atmospheric carbon dioxide emissions project to have occurred.

While the discrepancy between real world observations and climate model projections of temperature rise in the lower atmosphere has been recognized for a number of years, the question has remained as to whether the “problem” lies within the climate models or the observations. With this new data release, the trend in the UAH data now matches very closely with the trend through an independent compilation of the satellite-temperature observations maintained by a team of researchers at Remote Sensing Systems (RSS). The convergence of the observed data sets is an indication the climate models are the odd man out.

As with most long-term, real-world observations, the data are covered in warts. The challenge posed to Spencer et al. was how to splice together remotely sensed data collected from a variety of instruments carried aboard a variety of satellites in unstable orbits—and produce a product robust enough for use in climate studies. The details as to how they did it are explained as clearly as possible in this post over at Spencer’s website (although still quite a technical post). The post provides good insight as to why raw data sets need to be “adjusted”—a lesson that should be kept in mind when considering the surface temperature compilations as well. In most cases, using raw data “as is” is an inherently improper thing to do, and the types of adjustments that are applied may vary based upon the objective.

Here is a summary of the new data set and what was involved in producing it:

Version 6 of the UAH MSU/AMSU global satellite temperature data set is by far the most extensive revision of the procedures and computer code we have ever produced in over 25 years of global temperature monitoring. The two most significant changes from an end-user perspective are (1) a decrease in the global-average lower tropospheric (LT) temperature trend from +0.140 C/decade to +0.114 C/decade (Dec. ’78 through Mar. ’15); and (2) the geographic distribution of the LT trends, including higher spatial resolution. We describe the major changes in processing strategy, including a new method for monthly gridpoint averaging; a new multi-channel (rather than multi-angle) method for computing the lower tropospheric (LT) temperature product; and a new empirical method for diurnal drift correction… The 0.026 C/decade reduction in the global LT trend is due to lesser sensitivity of the new LT to land surface skin temperature (est. 0.010 C/decade), with the remainder of the reduction (0.016 C/decade) due to the new diurnal drift adjustment, the more robust method of LT calculation, and other changes in processing procedures.

Figure 1 shows a comparison of the data using the new procedures with that derived from the old procedures. Notice that in the new dataset, the temperature anomalies since about 2003 are less than those from the previous version. This has the overall effect of reducing the trend when computed over the entirety of the record.

Figure 1. Monthly global-average temperature anomalies for the lower troposphere from Jan. 1979 through March, 2015 for both the old and new versions of LT (source: www.drroyspencer.com)


Figure 1. Monthly global-average temperature anomalies for the lower troposphere from Jan. 1979 through March 2015 for both the old and new versions of LT. (Source: www.drroyspencer.com)

While this new version, admittedly, is not perfect, Spencer, Christy, and Braswell see it as an improvement over the old version. Note that this is not the official release, but rather a version the authors have released for researchers to examine and see if they can find anything that looks irregular that may raise questions as to the procedures employed. Spencer et al. expect a scientific paper on the new data version to be published sometime in 2016.

But unless something major comes up, the new satellite data are further evidence the earth is not warming as expected.  That means that, before rushing into “moral obligations” to attempt to alter the climate’s future course by restricting energy production, we perhaps ought to spend more time trying to better understand what it is we should be expecting in the first place.

One of the things we are told by the more alarmist crowd that we should expect from our fossil fuel burning is a large and rapid sea level rise, primarily a result of a melting of the ice sheets that rest atop Greenland and Antarctica. All too frequently we see news stories telling tales of how the melting in these locations is “worse than we expected.” Some soothsayers even attack the United Nations’ Intergovernmental Panel on Climate Change (IPCC) for being too conservative (of all things) when it comes to projecting future sea level rise. While the IPCC projects a sea level rise of about 18–20 inches from its mid-range emissions scenario over the course of this century, a vocal minority clamor that the rise will be upwards of 3 feet and quite possibly (or probably) greater. All the while, the sea level rise over the past quarter-century has been about 3 inches.

But as recent observations do little to dissuade the hardcore believers, perhaps model results (which they are seemingly more comfortable with) will be more convincing.

A new study available this week in the journal Geophysical Research Letters is described by author Miren Vizcaino and colleagues as “a first step towards fully-coupled higher resolution simulations with more advanced physics”—basically, a detailed ice sheet model coupled with a global climate model.

They ran this model combination with the standard IPCC emissions scenarios to assess Greenland’s contribution to future sea level rise. Here’s what they found:

The [Greenland ice sheet] volume change at year 2100 with respect to year 2000 is equivalent to 27 mm (RCP 2.6), 34 mm (RCP 4.5) and 58 mm (RCP 8.5) of global mean SLR.

Translating millimeters (mm) into inches give this answer: a projected 21st century sea level rise of 1.1 in. (for the low emissions scenario; RCP 2.6), 1.3 in. (for the low/mid scenario; RCP 4.5), and 2.3 in (for the IPCC’s high-end emission scenario). Some disaster.

As with any study, the authors attach some caveats:

The study presented here must be regarded as a necessary first step towards more advanced coupling of ice sheet and climate models at higher resolution, for instance with improved surface-atmosphere coupling (e.g., explicit representation of snow albedo evolution), less simplified ice sheet flow dynamics, and the inclusion of ocean forcing to Greenland outlet glaciers.

Even if they are off by 3–4 times, Greenland ice loss doesn’t seem to be much of a threat. Seems like it’s time to close the book on this imagined scare scenario.

And while imagination runs wild when it comes to linking carbon dioxide emissions to calamitous climate changes and extreme weather events (or even war and earthquakes),  imagination runs dry when it comes to explaining non-events (except when non-events string together to produce some sort of negative outcome [e.g., drought]).

Case in point, a new study looking into the record-long absence of major hurricane (category 3 or higher) strikes on the U.S. mainland—an absence that exceeds nine years (the last major hurricane to hit the U.S was Hurricane Wilma in late-October 2005). The authors of the study, Timothy Hall of NASA’s Goddard Institute for Space Studies and Kelly Hereid from ACE Tempest Reinsurance, concluded that while a streak this long is rare, their results suggest “there is nothing unusual underlying the current hurricane drought. There’s no extraordinary lack of hurricane activity.” Basically they concluded that it’s “a case of good luck” rather than “any shift in hurricane climate.”

That is all well and good, and almost certainly the case. Of course, the same was true a decade ago when the United States was hit by seven major hurricanes over the course of two hurricane seasons (2004 and 2005)—an occurrence that spawned several prominent papers and endless discussion pointing the finger squarely at anthropogenic climate change. And the same is true for every hurricane that hits the United States, although this doesn’t stop someone, somewhere, from speculating to the media that the storm’s occurrence was “consistent with” expectations from a changing climate.

What struck us as odd about the Hall and Hereid paper is the lack of speculation as to how the ongoing record “drought” of major hurricane landfalls in the United States could be tied in with anthropogenic climate change. You can rest assured—and history will confirm—that if we had been experiencing a record run of hurricane landfalls, researchers would be falling all over themselves to draw a connection to human-caused global warming.

But the lack of anything bad happening? No way anyone wants to suggest that is “consistent with” expectations. According to Hall and Hereid:

A hurricane-climate shift protecting the US during active years, even while ravaging nearby Caribbean nations, would require creativity to formulate. We conclude instead that the admittedly unusual 9-year US Cat3+ landfall drought is a matter of luck. [emphasis added]

Right! A good string of weather is “a matter of luck” while bad weather is “consistent with” climate change.

It’s not like it’s very hard, or (despite the authors’ claim) it requires much “creativity” to come up with ways to construe a lack of major hurricane strikes on U.S. soil to be “consistent with” anthropogenic climate change. In fact, there are loads of material in the scientific literature that could be used to construct an argument that under global warming, the United States should experience fewer hurricane landfalls. For a rundown of them, see p. 30 of our comments on the government’s National Assessment on Climate Change, or check out our piece titled, “Global Savings: Billion-Dollar Weather Events Averted by Global Warming.”

It is not for lack of material, but rather, for lack of desire, that keeps folks from wanting to draw a potential link between human-caused climate change and good things occurring in the world.


Hall, T., and K. Hereid. 2015. “The Frequency and Duration of US Hurricane Droughts.” Geophysical Research Letters, doi:10.1002/2015GL063652

Vizcaino, M. et al. 2015. “Coupled Simulations of Greenland Ice Sheet and Climate Change up to AD 2300.” Geophysical Research Letters, doi: 10.1002/2014GL061142

You Ought to Have a Look: Curry on Worry

You Ought to Have a Look is a feature from the Center for the Study of Science posted by Patrick J. Michaels and Paul C. (“Chip”) Knappenberger. While this section will feature all of the areas of interest that we are emphasizing, the prominence of the climate issue is driving a tremendous amount of web traffic. Here we post a few of the best in recent days, along with our color commentary.

This week, we have two notable items of interest.

First and foremost, a must-read article from Judith Curry’s Climate Etc. blog where Judy quite adeptly introduces us to the concept of an “availability cascade”—a process that has come to dominate and define climate alarmism. Curry writes that an

availability cascade is a self-reinforcing process of collective belief formation that triggers a self-perpetuating chain reaction: the more attention a danger gets, the more worried people become, leading to more news coverage and greater alarm.

She describes how the cascade of events began with the 1992 United Nations Rio Treaty aimed at “avoiding dangerous climate change through stabilization of [carbon dioxide] emissions,” transformed from “global warming” to “climate change” so as to pick up extreme weather events, and now has swept human health into the growing avalanche of woe.

Judy’s article is one of the best pieces we have read on the web is recent weeks (and we’re not just saying that because she incorporates some of our work!). Bravo to her! Here is a longer excerpt, but you (really, really) ought to have a look at the whole thing:

White House Announces Initiative to Focus on Health Concerns of Global Warming: We’ve Already Done It For Them!

Global Science Report is a weekly feature from the Center for the Study of Science, where we highlight one or two important new items in the scientific literature or the popular media. For broader and more technical perspectives, consult our monthly “Current Wisdom.”

It seems like the Obama Administration is a bit behind the times when it comes to today’s announcement that it will start a new initiative to focus on the health effects of climate change.

There is no need for the White House to outlay federal resources for the time and effort that will be involved—we have already done it for them (and, undoubtedly, for a minuscule fraction of the price)!

Two and a half years ago, we released a publication titled “ADDENDUM: Global Climate Change Impacts in the United States” that basically was a non-government-influenced look at how climate change would likely impact the United States in the future, based a lot on current trends in climate and society. We titled it an “ADDENDUM” because the U.S. Global Change Research Program, back in 2009, released a similarly titled report that was so incomplete that, well, it needed an addendum. We knew the government wasn’t going to supply one, so we produced one ourselves.

In our report (available here), we included a chapter on human health. Here are the key messages from that chapter:

  • The health effects of climate change on the United States are negligible today, and likely to remain so in the future, unless the United States goes into precipitous economic and technological decline.
  • Death certificate data indicate that 46 percent of all deaths from extreme weather events in the United States from 1993-2006 were from excessive cold, 28 percent were from excessive heat, 10 percent were from hurricanes, 7 percent were from floods, and 4 percent were from tornadoes.
  • Over the long term, deaths from extreme weather events have declined in the United States.
  • Deaths in the United States peak in the colder months and are at a minimum in the warmer months.
  • In U.S. cities, heat-related mortality declines as heat waves become stronger and/or more frequent.
  • Census data indicate that the migration of Americans from the cold northern areas to the warmer southwest saves about 4,600 lives per year and is responsible for three to seven per cent of the gains in life expectancy from 1970-2000.
  • While the U.S. Global Change Research Program states that “Some diseases transmitted by food, water, and insects are likely to increase,” incidence of these diseases have been reduced by orders of magnitude in the United States over the past century, and show no sign of resurgence.

We effectively show that if you want to focus on the health of Americans, there is no need to bring climate change into the equation—especially if you are hoping to find negative impacts (which appears to be the goal of the Administration).

Scads of new science–on everything from heat-related mortality, to asthma, to extreme weather–continues to support that general conclusion.

Of note is that accompanying today’s White House announcement is an announcement from the USGCRP that it has produced its own reportThe Impacts of Climate Change on Human Health in the United States: A Scientific Assessment.”

Based on loads of past experience with the USGCRP, we can only imagine the worst.

Public comments on this draft of the USGCRP report are due on June 8, 2015. It’s on our calendar.