April 25, 2018 2:11PM

Some More Insensitivity about Global Warming

Hot off the press, in yesterday’s Journal of Climate, Nic Lewis and Judith Curry have re-calculated the equilibrium climate sensitivity (ECS) based upon the historical uptake of heat into the ocean and human emissions of greenhouse gases and aerosols. ECS is the net warming one expects for doubled atmospheric carbon dioxide. Their ECS ranges from 1.50 to 1.56 degrees Celsius.

Nic has kindly made the manuscript available here, so you don’t have to shell out $35 to the American Meteorological Society for a one-day view.

The paper is a follow-on to their 2015 publication that had a median ECS of 1.65⁰C. It was criticized for not using the latest-greatest “infilled” temperature history (in which less-than-global coverage becomes global using the same data) in order to derive the sensitivity. According to Lewis, writing yesterday on Curry’s blog, the new paper “addresses a range of concerns that have been raised about climate sensitivity estimates” like those in their 2015 paper.

The average ECS from the UN’s Intergovernmental Panel on Climate Change (IPCC) is 3.4⁰C, roughly twice the Lewis and Curry values. It somehow doesn’t seem surprising that the observed rate of warming is now running at about half of the rate in the UN’s models, does it?

Lewis and Curry's paper appeared seven days after Andrew Dessler and colleagues showed that the mid-atmospheric temperature in the tropics is the best indicator of the earth’s energy balance. This means that any differences between observed and forecast midatmospheric temperatures there can be used to adjust the ECS.

Late last year, University of Alabama’s John Christy and Richard McNider showed that the observed rate of warming in the tropical mid-atmosphere is around 0.13⁰C/decade since 1979, while the model average forecast is 0.30⁰C/decade. This adjusts down the IPCC’s average ECS to the range of 1.5⁰C (actually 1.46⁰).

That’s three estimates of ECS all in the same range, and all approximately half of the UN’s average. 

It seems the long-range temperature forecast most consistent with these findings would be about half of what the IPCC is forecasting. That would put total human warming to 2100 right around the top goal of the Paris Accord, or 2.0⁰C.

Stay tuned on this one, because that might be in the net benefit zone.

December 2, 2016 4:16PM

You Ought to Have a Look: Climate Fretting and Why It’s Unjustified

You Ought to Have a Look is a regular feature from the Center for the Study of Science. 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.

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While “climate fretting” has become a pastime for some—even more so now with President-elect Trump’s plans to disassemble much of President Obama’s “I've Got a Pen and I've Got a Phone”-based Climate Action Plan—climate reality tells a much different story.

For example, a new analysis by Manhattan Institute’s (and YOTHAL favorite) Oren Cass looks into the comparative costs of climate changevs. climate action. His report, “Climate Costs in Context” is concise and to-the-point, and finds that while climate change will impart an economic cost, it is manageable and small in comparison to the price of actively trying to mitigate it. Here’s Oren’s abstract:

There is a consensus among climate scientists that human activity is contributing to climate change. However, claims that rising temperatures pose an existential threat to the human race or modern civilization are not well supported by climate science or economics; to the contrary, they are every bit as far from the mainstream as claims that climate change is not occurring or that it will be beneficial. Analyses consistently show that the costs of climate change are real but manageable. For instance, the prosperity that the world might achieve in 2100 without climate change may instead be delayed until 2102. [emphasis added]

In other words, the economic impacts of climate change aren’t something worth fretting over.

Next up is a contribution (at Judith Curry’s blog, Climate Etc.) from Nic Lewis showing more evidence that the temperature response in most climate models is too sensitive to changes in atmospheric carbon dioxide concentrations. Nic reviews a new paper that suggests the paltry increase in global average temperature in recent decades may continue for another decade or more from forces of natural variability alone, and then adds his own analysis showing that an alternative view supported by the paper is that the transitive climate sensitivity (TCS; how much the global average surface temperature rises at the time of a doubling of the atmospheric carbon dioxide concentration) is rather low. Instead of the climate model average TCS of around 1.8°C, Nic finds observational support for a TCS of about 1.35°C. From this information, he concludes:

Based on these estimates, the average TCR [transient climate response] of [current climate] models likely exceeds that in the real world by about 30%...the future warming projected by [these] models is on average 65% or more above that projected by simple but physically-consistent models with a TCR of ~1.35 K.

Rather than fret about high-end climate change scenarios, folks ought embrace lukewarming as the way of the future.

And finally this week, Ron Bailey produces a dose of reality in his latest article for Reason.comEnergy Poverty Is Much Worse for the Poor Than Climate Change.” In his piece, Ron reviews a recent report, “Energy for Human Development” from The Breakthrough Institute that argues for prioritizing energy access over climate concerns. According to Ron:

[T]he Breakthrough writers call for prioritizing energy development for productive, large-scale economic enterprises. Copious and reliable energy will accelerate the creation and spread of higher-productivity factories and businesses, which then will generate the opportunities for a better life; that, in turn, will draw poor subsistence farmers into cities. They further note that energy access and electricity access are not the same thing. In fact, in 2012 electricity accounted for only about 18 percent of the energy consumed globally. "Efforts to address energy poverty must address needs for transportation fuels and infrastructure, and for fertilizer and mechanization of agriculture," they argue.

But what about climate change? Current renewable sources of energy are not technologically capable of lifting hundreds of millions of people out of energy poverty. Consequently, the Breakthrough writers see "no practical path to universal access to modern levels of energy consumption" that keeps the projected increase in global average temperature below the Paris Agreement on climate change goal of 2 degrees Celsius above the pre-industrial level. This implies that atmospheric concentrations of carbon dioxide will exceed 450 parts per million.

Ron continues:

They correctly point out that forcing poor people to forego economic development in order to prevent climate change is a "morally dubious proposition." They additionally observe that the wealth and technology produced by economic growth increases resilience to climatic extremes and other natural disasters. When bad weather encounters poverty, disaster ensues.

The overarching conclusion from all of the above is one that we have championed since the start—what’s really worth fretting about is climate policy (not climate change). To this end, the Trump Administration ought to ease such fretting.

May 27, 2016 11:18AM

You Ought to Have a Look: Smoke, Clouds and Snowfall

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.

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In this week’s YOTHAL edition, we’ll focus on some recent climate science findings that deserve further mention and are worthy of a deeper dive. If and when you have the time and/or inclination, you ought to have a look.

First up is a collection of papers that describe the results of a several experiments looking into cloud formation—or rather, into the availability and development of the aerosol particles that aid in cloud formation. The tiny aerosols are called cloud condensation nuclei (CCN) and without them, it is very difficult for clouds to form. 

It’s well known that sulfate particles, formed as a by-product of fossil fuel burning (primarily coal and oil), make for a good source of CCN. In fact, the change in cloud characteristics resulting from this form of air pollution are thought to have asserted a cooling pressure on the earth’s surface temperature—a cooling that has acted to offset a certain portion of the warming caused by the co-incidental emissions of carbon dioxide and other greenhouse gases.

Just how much warming has been offset by human-induced changes in cloud characteristics is one of the great unknowns in climate science today. Which is unfortunate, as it is a key to understanding how sensitive the earth’s climate is to increasing atmospheric concentrations of greenhouse gases. The less warming offset by enhanced cloud cooling, the less warming caused by greenhouse gas increases.

What the new research found was even in the absence of sulfate aerosols, there are plenty of other sources of potential CCN—a primary one being chemical emissions (known as volatile organic compounds, or VOCs) from plants. Through various processes, which the researchers found involve cosmic galactic rays, the plant VOCs can pretty efficiently transform and grow into CCN.

The bottom line from the new research findings is that the world was probably a cloudier place in the pre-industrial period than it has been generally realized. The implication is that human sulfate emissions haven’t altered cloud characteristics to the degree currently assumed—which means that current assumptions overestimate the magnitude of the anthropogenic cooling enhancement and thus overestimate the warming influence of greenhouse gas emissions (that is, the earth’s climate sensitivity is less than previously determined).

A good review of these three new experimental results (two of which were published in Nature and the other, simultaneously, in Science) and their implications is found in this news piece in Science that accompanied the papers’ publication. Here’s a teaser:

In other words, Earth is less sensitive to greenhouse gases than previously thought, and it may warm up less in response to future carbon emissions, says Urs Baltensperger of the Paul Scherrer Institute, who was an author on all three papers. He says that the current best estimates of future temperature rises are still feasible, but "the highest values become improbable." The researchers are currently working toward more precise estimates of how the newly discovered process affects predictions of the Earth's future climate.

At the very least, the Science overview article is worth a read. If you are interested further, you can have a look at the papers themselves (see links in reference list)—although, fair warming, they are quite technical.

Next up is an excellent review paper on wildfire occurrence in a warming world. The article, jointly authored by Stefan Doerr and Cristina Santín of Swansea University is part of a special issue of the Philosophical Transactions of the Royal Society B dedicated to “The interaction of fire and mankind.” Doerr and Santín take us through the extant literature of the trends and variability of fire occurrence and the factors influencing them. What they find is in stark opposition to the conclusion that you’d come to by reading the mainstream press. To hear the authors tell it:

Wildfire has been an important process affecting the Earth's surface and atmosphere for over 350 million years and human societies have coexisted with fire since their emergence. Yet many consider wildfire as an accelerating problem, with widely held perceptions both in the media and scientific papers of increasing fire occurrence, severity and resulting losses. However, important exceptions aside, the quantitative evidence available does not support these perceived overall trends. Instead, global area burned appears to have overall declined over past decades, and there is increasing evidence that there is less fire in the global landscape today than centuries ago.

This is an eye-opening read in light of the hype surrounding the Ft. McMurray fires of recent weeks and the general warming-is-causing-more-fires-trope that is paraded out every time there is a fire burning somewhere in the US.  The authors go on to note that “[t]he media still promote perceptions of wildfire as the enemy even in very fire-prone regions, such as the western USA...”

And finally is a paper examining what the paleo-history of Greenland tells us about the relationship between higher temperatures and snowfall there. A research team led by University at Buffalo’s Elizabeth Thomas analyzed “aquatic leaf wax” records from sediment cores extracted from a lakebed in western Greenland to reconstruct a temperature and precipitation profile there over the past 8,000 years. Thomas and colleagues found that winter precipitation (snowfall) during a multi-millennial period of warmer-than-current temperatures in Greenland (extending from about 4,000 to 6,000 years ago) was substantially increased.

The proposed mechanism is that the warmer temperatures resulted in reduced sea ice in the nearby Baffin Bay and Labrador Sea which raised the regional moisture availability and increased snowfall.  The enhanced snowfall acted to offset some of the summer ice sheet melting that occurred with the higher temperatures, thereby slowing sea level rise. The authors suggest that a similar mechanism should accompany the current period of rising temperatures. They summarize:

The response of the western GrIS [Greenland Ice Sheet] to higher summer temperatures may have been muted due to increased accumulation in the middle Holocene. Our results suggest that in the future, as Arctic seas warm and sea ice retreats, increased winter precipitation may enhance accumulation on parts of the GrIS and partly offset summer ablation, particularly in areas close to modern winter sea ice fronts.

This result would seem to temper the scare stories of several meters of sea level rise in the coming century that have been circulating around the press—but, predictably, it’s been crickets from those press outlets.

Read more about in this press release, and/or from the paper itself.

 

References:

Bianchi, F., et al., 2016. New particle formation in the free troposphere: A question of chemistry and timing. Sciencedoi: 10.1126/science.aad5456.

Doerr, S. and C. Santín, 2016. Global trends in wildfire and its impacts: perceptions versus realities in a changing world.Philosophical Transactions of the Royal Society B, doi: 10.1098/rstb.2015.0345.

Kirkby, J., et al., 2016. Ion-induced nucleation of pure biogenic particles. Nature, 533, 521–526, doi:10.1038/nature17953.

Thomas, E., et al., 2016. A major increase in winter snowfall during the middle Holocene on western Greenland caused by reduced sea ice in Baffin Bay and the Labrador Sea. Geophysical Research Letters, doi: 10.1002/2016GL068513.

Tröstle, J., et al., 2016. The role of low-volatility organic compounds in initial particle growth in the atmosphere. Nature, 533, 527–531, doi:10.1038/nature18271.

 

May 25, 2016 1:13PM

You Ought to Have a Look: Ontario’s Energy Plan, Evidence‐​based Policy and a New Climate Sensitivity Estimate

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.

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First up in this week’s edition of You Ought to Have a Look is an op-ed by Ross McKitrick (one-time Cato Adjunct who is now Chair of Energy, Ecology & Prosperity at the Frontier Centre for Public Policy and Economic Professor at the University of Guelph) who shreds the energy policy being forwarded by Kathleen Wynne, the Liberal Party Premier of Ontario. Wynne’s proposed plan—aimed to combat climate change—includes, among other things, a requirement that all homes eventually be heated by electricity (i.e., no natural gas, etc.).

McKitrick describes up the plan,

Around the time that today’s high-school students are readying to buy their first home, it will be illegal for builders to install heating systems that use fossil fuels, in particular natural gas. Having already tripled the price of power, Queen’s Park will make it all but mandatory to rely on electricity for heating.

There will be new mandates and subsidies for biofuels, electric buses for schools, extensive new bike lanes to accommodate all those bicycles Ontario commuters will be riding all winter, mandatory electric recharging stations on all new buildings, and many other Soviet-style command-and-control directives.

distills what’s wrong with it,

[E]ven if the…plan were to stop global warming in its tracks, the policies would do more economic harm than the averted climate change.

and, in inimitable Ross fashion, throws in this zinger,

The scheme is called the Climate Change Action Plan, or CCAP, but it would be more appropriately called the Climate Change Coercion Plan: the CCCP.

The entire op-ed appearing in the Financial Post is a must read.

Next up is a post at the blog IPKat (a U.K.-based Intellectual Property news blog) by Nicola Searle that provides an interesting review of a new book by Paul Cairney titled The Politics of Evidence-Based Policy Making.

Evidenced-based policy making (EBPM) is the idea that, well, policy should be based on some sort of evidence. But as Searle (and Cairney) point out, this is a lot more complicated than it seems. Searle eloquently describes the situation as: “Policymaking isn’t a Mondrian, it’s a Monet.”

Rather than the (utopian) linear view that “evidence” clearly informs the best “policy,” the situation is much more complex and involves uncertainties, interpretations, personal beliefs, outside pressures, policy goals, etc.

Searle provides this analogy:

As Cairney puts it, "in the real world, the evidence is contested, the policy process contains a large number of influential actors, and scientific evidence is one of many sources of information." I'd described policy making in general as akin to an extended family choosing which film to watch. Uncle Alex campaigns for Barbarella, cousin Vic, holding the remote, decides you’re all watching Hulk until your sister Pat throws a tantrum unless you watch Frozen. You might consult the Rotten Tomatoes rating, but you're convinced that critic from the New York Post is on the payroll of a major studios and the popular rating seems to have been spammed by bots... In the end you watch a Jude Law rom-com. And that’s the simplified version.

For more insight, check out Searle’s full post, or perhaps even Cairney’s book. This is a topic that is quite relevant to the subject of climate change policy (as well as a litany of policy that is rooted in U.S. Environmental ProtectionAgency “evidence”).

And finally, we’d be remiss if we didn’t draw attention to a new study appearing in the AGU journal Earth and Space Science by University College Dublin’s J. Ray Bates that finds that the equilibrium climate sensitivity—that is, the earth’s total surface temperature rise that results from a doubling of the atmospheric effective concentration of carbon dioxide—is “~1°C.”

Bates’ work is an update and extension of the methods and findings of (Cato Center for the Study of Science's Distinguished Senior Fellow) Richard Lindzen and Yong-Sang Choi and represents another estimate of the climate sensitivity that falls well below the average of the climate models (3.2°C) used in the most recent IPCC report.  The lower the climate sensitivity to greenhouse gas increases, the lower the overall impacts when measured over comparative time-scales.

We’ve added the new Bates results to our lower-than-model climate sensitivity compilation (Figure 1).

Figure 1. Equilibrium climate sensitivity (ECS) estimates from new research beginning in 2011 (colored), compared with the assessed range given in the Intergovernmental Panel on Climate Change (IPCC) Fifth Assessment Report (AR5) and the collection of climate models used in the IPCC AR5. The “likely” (greater than a 66% likelihood of occurrence) range in the IPCC Assessment is indicated by the gray bar. The arrows indicate the 5 to 95 percent confidence bounds for each estimate along with the best estimate (median of each probability density function; or the mean of multiple estimates; colored vertical line). The right-hand side of the IPCC AR5 range is actually the 90% upper bound (the IPCC does not actually state the value for the upper 95% confidence bound of their estimate). Ring et al. (2012) present four estimates of the climate sensitivity and the red box encompasses those estimates. Likewise, Bates (2016) presents eight estimates and the green box encompasses them. Spencer and Braswell (2013) produce a single ECS value best-matched to ocean heat content observations and internal radiative forcing.

 

Figure 1. Equilibrium climate sensitivity (ECS) estimates from new research beginning in 2011 (colored), compared with the assessed range given in the Intergovernmental Panel on Climate Change (IPCC) Fifth Assessment Report (AR5) and the collection of climate models used in the IPCC AR5. The “likely” (greater than a 66% likelihood of occurrence) range in the IPCC Assessment is indicated by the gray bar. The arrows indicate the 5 to 95 percent confidence bounds for each estimate along with the best estimate (median of each probability density function; or the mean of multiple estimates; colored vertical line). The right-hand side of the IPCC AR5 range is actually the 90% upper bound (the IPCC does not actually state the value for the upper 95% confidence bound of their estimate). Ring et al. (2012) present four estimates of the climate sensitivity and the red box encompasses those estimates. Likewise, Bates (2016) presents eight estimates and the green box encompasses them. Spencer and Braswell (2013) produce a single ECS value best-matched to ocean heat content observations and internal radiative forcing.

As the Bates results are just-released, we await to see how they stand up to scrutiny (and the test of time).

The journal Earth and Space Science is open access, so everyone can go and have a look for themselves (although, fair warning, the article is very technical).

March 27, 2015 5:39PM

You Ought to Have a Look: Climate Sensitivity and Environmental Worries Are Trending Downward

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.



More evidence this week that high-end forecasts of coming climate change are unsupportable and Americans’ worry about environmental threats, including global warming, is declining. Maybe the general public isn’t as out of touch with the science as has been advertised?

First up is a new paper by Bjorn Stevens from Germany’s Max Plank Institute for Meteorology that finds the magnitude of the cooling effect from anthropogenic aerosol emissions during the late 19th and 20th century was less than currently believed, which eliminates the support for the high-end negative estimates (such as those included in the latest assessment of the U.N.’s Intergovernmental Panel on Climate Change, IPCC). Or, as Stevens puts it “that aerosol radiative forcing is less negative and more certain than is commonly believed.”

This is important, because climate models rely on the cooling effects from aerosol emissions to offset a large part of the warming effect from greenhouse gas emissions. If you think climate models produce too much warming now, you ought to see how hot they become when they don’t include aerosol emissions. The IPCC sums up the role of aerosols this way:

Despite the large uncertainty range, there is a high confidence that aerosols have offset a substantial portion of [greenhouse gas] global mean forcing.

The new Stevens’ result—that the magnitude of the aerosol forcing is less—means the amount of greenhouse gas-induced warming must also be less; which means that going forward we should expect less warming from future greenhouse gas emissions than climate models are projecting.

Researcher Nic Lewis, who has done a lot of good recent work on climate sensitivity, was quick to realize the implications of the Stevens’ results. In a blog post over at Climate Audit, Lewis takes us through his calculations as to what the new aerosols cooling estimates mean for observational determinations of the earth’s climate sensitivity.

What he finds is simply astounding.

Instead of the IPCC’s estimate that the equilibrium climate sensitivity likely lies between  1.5°C and 4.5°C, Lewis finds the likely range to be 1.2°C to 1.8°C (with a best estimate of 1.45°C). Recall that the average equilibrium climate sensitivity from the climate models used by the IPCC to make future projections of climate change and its impacts is 3.2°C—some 120% greater than Lewis’ best estimate. But perhaps even more important than the best estimate is the estimate of the upper end of the range, which drops from the IPCC’s 4.5°C down to 1.8°C.

This basically eliminates the possibly of catastrophic climate change—that is, climate change that proceeds at a rate that exceeds our ability to keep up. Such a result will also necessarily drive down estimates of social cost of carbon thereby undermining a key argument use by federal agencies to support increasingly burdensome regulations which seek to reduce greenhouse gas emissions.

If this Stevens/Lewis result holds up, it is the death blow to global warming hysteria.

 

Which brings us to the last results of Gallup’s annual poll gauging the level of environmental concern among Americans—something the polling agency has been keeping track of since the late 1980s. 

Here’s Gallup’s summary of this year’s results:

Americans' concern about several major environmental threats has eased after increasing last year. As in the past, Americans express the greatest worry about pollution of drinking water, and the least about global warming or climate change.

And Gallup’s full write-up includes this gem:

Importantly, even as global warming has received greater attention as an environmental problem from politicians and the media in recent years, Americans' worry about it is no higher now than when Gallup first asked about it in 1989.

Media Name: gallupenvironment32715.png

Says something about the effectiveness of the climate alarm campaign.

The full set of questions and results are available here. You ought to have a look!

September 25, 2014 5:09PM

The Collection of Evidence for a Low Climate Sensitivity Continues to Grow

Global Science Report is a 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.”

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Nic Lewis and Judith Curry just published a blockbuster paper that pegs the earth’s equilibrium climate sensitivity—how much the earth’s average surface temperature is expected to rise in association with a doubling of the atmosphere’s carbon dioxide concentration—at 1.64°C (1.05°C to 4.05°C, 90% range), a value that is nearly half of the number underpinning all of President Obama’s executive actions under his Climate Action Plan.

This finding will not stop the President and the EPA from imposing more limits on greenhouse-gas emissions from fossil fuels. A wealth of similar findings have appeared in the scientific literature beginning in 2011 (see below) and they, too, have failed to dissuade him from his legacy mission.

The publication of the Lewis and Curry paper, along with another by Ragnhild Skeie and colleagues, brings the number of recent low-sensitivity climate publications to 14, by 42 authors from around the world (this doesn’t count our 2002 paper on the topic, “Revised 21st Century Temperature Projections”).  Most of these sensitivities are a good 40% below the average climate sensitivity of the models used by the U.N.’s Intergovernmental Panel on Climate Change (IPCC).

Lewis and Curry arrive at their lower equilibrium climate sensitivity estimate by using updated compilations of the earth’s observed temperature change, oceanic heat uptake, and the magnitude of human emissions, some of which should cause warming (e.g., greenhouse gases), while the others should cool (e.g., sulfate aerosols). They try to factor out “natural variability.” By comparing values of these parameters from the mid-19 century to now, they can estimate how much the earth warmed in association with human greenhouse gas emissions.

The estimate is not perfect, as there are plenty of uncertainties, some of which may never be completely resolved. But, nevertheless, Lewis and Curry have generated  a very robust observation-based estimate of the equilibrium climate sensitivity.

For those interested in the technical details, and a much more thorough description of the research, author Nic Lewis takes you through the paper (here) has made a pre-print copy of the paper freely available (here).

In the chart below, we’ve added the primary findings of Lewis and Curry as well as those of Skeie et al. to the collection of 12 other low-sensitivity papers published since 2010 that conclude that the best estimate for the earth’s climate sensitivity lies below the IPCC estimates. We’ve also included in our Figure both the IPCC’s  subjective and model-based characteristics of the equilibrium climate sensitivity. For those wondering, there are very few recent papers arguing that the IPCC estimates are too low, and they all have to contend with the fact that, according to new Cato scholar Ross McKitrick, “the pause” in warming is actually 19 years in length. 

Media Name: gsr_092514_fig1.png

 

Figure 1. Climate sensitivity estimates from new research beginning in 2011 (colored), compared with the assessed range given in the Intergovernmental Panel on Climate Change (IPCC) Fifth Assessment Report (AR5) and the collection of climate models used in the IPCC AR5. The “likely” (greater than a 66% likelihood of occurrence)range in the IPCC Assessment is indicated by the gray bar. The arrows indicate the 5 to 95 percent confidence bounds for each estimate along with the best estimate (median of each probability density function; or the mean of multiple estimates; colored vertical line). Ring et al. (2012) present four estimates of the climate sensitivity and the red box encompasses those estimates. The right-hand side of the IPCC AR5 range is actually the 90% upper bound (the IPCC does not actually state the value for the upper 95 percent confidence bound of their estimate). Spencer and Braswell (2013) produce a single ECS value best-matched to ocean heat content observations and internal radiative forcing.

 

References:

Aldrin, M., et al., 2012. Bayesian estimation of climate sensitivity based on a simple climate model fitted to observations of hemispheric temperature and global ocean heat content. Environmetrics, doi: 10.1002/env.2140.

Annan, J.D., and J.C Hargreaves, 2011. On the genera­tion and interpretation of probabilistic estimates of climate sensitivity. Climatic Change, 104, 324-436.

Hargreaves, J.C., et al., 2012. Can the Last Glacial Maximum constrain climate sensitivity? Geophysical Research Letters, 39, L24702, doi: 10.1029/2012GL053872

Lewis, N. 2013. An objective Bayesian, improved approach for applying optimal fingerprint techniques to estimate climate sensitivity. Journal of Climate, doi: 10.1175/JCLI-D-12-00473.1.

Lewis, N. and J.A. Curry, C., 2014. The implications for climate sensitivity of AR5 focring and heat uptake estimates. Climate Dynamic, 10.1007/s00382-014-2342-y.

Lindzen, R.S., and Y-S. Choi, 2011. On the observational determination of climate sensitivity and its implica­tions. Asia-Pacific Journal of Atmospheric Science, 47, 377-390.

Loehle, C., 2014. A minimal model for estimating climate sensitivity. Ecological Modelling, 276, 80-84.

Masters, T., 2013. Observational estimates of climate sensitivity from changes in the rate of ocean heat uptake and comparison to CMIP5  models. Climate Dynamics, doi:101007/s00382-013-1770-4

McKitrick, R., 2014. HAC-Robust Measurement of the Duration of a Trendless Subsample in a Global Climate Time Series. Open Journal of Statistics4, 527-535. doi: 10.4236/ojs.2014.47050.

Michaels. P.J. et al., 2002. Revised 21st century temperature projections. Climate Research, 23, 1-9.

Otto, A., F. E. L. Otto, O. Boucher, J. Church, G. Hegerl, P. M. Forster, N. P. Gillett, J. Gregory, G. C. Johnson, R. Knutti, N. Lewis, U. Lohmann, J. Marotzke, G. Myhre, D. Shindell, B. Stevens, and M. R. Allen, 2013. Energy budget constraints on climate response. Nature Geoscience, 6, 415-416.

Ring, M.J., et al., 2012. Causes of the global warming observed since the 19th century. Atmospheric and Climate Sciences, 2, 401-415, doi: 10.4236/acs.2012.24035.

Schmittner,  A., et al. 2011. Climate sensitivity estimat­ed from temperature reconstructions of the Last Glacial Maximum. Science, 334, 1385-1388, doi: 10.1126/science.1203513.

Skeie,  R. B., T. Berntsen, M. Aldrin, M. Holden, and G. Myhre, 2014. A lower and more constrained estimate of climate sensitivity using updated observations and detailed radiative forcing time series. Earth System Dynamics, 5, 139–175.

Spencer, R. W., and W. D. Braswell, 2013. The role of ENSO in global ocean temperature changes during 1955-2011 simulated with a 1D climate model. Asia-Pacific Journal of Atmospheric Science, doi:10.1007/s13143-014-0011-z.

van Hateren, J.H., 2012. A fractal climate response function can simulate global average temperature trends of the modern era and the past millennium. Climate Dynamics,  doi: 10.1007/s00382-012-1375-3.

August 27, 2014 8:38AM

Climate Alarmism: When Is This Bozo Going Down?

Global Science Report is a 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.”

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Climate alarmism is like one of those pop-up Bozos. No matter how many times you bop it, up it springs. In fact, the only way to stop it, as most kids learn, is to deflate it. In this case, the air inside Bozo is your and my tax money.

Two scientific papers released last week combine for a powerful 1-2 haymaker, but, rest assured, Bozo springs eternal. The first says that human aerosol emissions are not that responsible for offsetting the warming influence of greenhouse gas emissions, while the second finds that the observed warming from human greenhouse gases is less than a lot of people think.

We aren’t at all surprised by the first result.  The cooling effect of sulphate particulates, which go into the air along with carbon dioxide when fossil fuels (mainly coal) are combusted, was only invoked in the mid-1980s, when the lack of warming predicted by computer models was embarrassingly obvious.

This is the kind of thing that the iconic historian of science, Thomas Kuhn, predicted in his classic book, The Structure of Scientific Revolutions. When a scientific “paradigm” is assaulted by reality, increasingly ornate and bizarre explanations are put forth to keep it alive. Sulfates smelled like one of those to us back in the 1980s, and now it looks like the excuses are finally getting comeuppance.

The second result also comes as little news to us, as we have been saying for years that the human carbon dioxide emissions are not the only player in the climate change game.

The two new papers, in combination, mean that the human influence on the climate from the burning of fossil fuels is far less than what the IPCC’s ensemble of climate models says it is. This also goes for the U.S. Global Change Research Program, the EPA ,and the White House.

Rest assured, though, Bozo will rise again—despite a near-continuous barrage of blows supporting the idea that the climate’s sensitivity to human greenhouse gas emissions is far too low to justify any of the expensive and futile actions emanating from Washington and Brussels.

The aerosol paper describes research by a team of Israeli scientists led by Gerald Stanhill (from the ARO Volcani Center) who examined the causes of “solar dimming” and “solar brightening” that have taken place over the past half-century or so. Solar brightening (dimming) refers to multidecadal periods when more (less) solar radiation is reaching the surface of the earth. All else being equal (dangerous words in Science), the earth’s surface would warm during periods of brightening and cool during dimming. Solar dimming has been reported to have taken place from the 1950s through the 1980s and since then there has been a period of recovery (i.e., brightening).  These patterns have been linked by many to human aerosol emissions caused by pernicious economic activity, with heavy emissions leading to global cooling from the 1950s (witness the opaque air of Pittsburgh and London) through the late 1970s and then, as air quality was cleaned up and aerosol emissions declined, an unmasking of the warming impact from greenhouse gas emissions.

This is an essential storyline that might as well have been written by Kuhn. Without invoking the previously undiscovered masking impact of human aerosols, climate models predict that far more global warming should have happened as a result of human greenhouse gas emissions than has been observed, even by the 1980s. Behaving more predictably than the climate, federal climatologists, led by Tom Wigley of the University Corporation for Atmospheric Research (hey, we couldn’t make up the name of that exclusively taxpayer-funded monster), relied on the aerosol “knob” to try to keep climate models from overheating.

Stanhill et al. have bad news for the feds. In their new paper, they examine the records of sunshine duration as recorded at five observation sites with long-term observations. When comparing these sunshine histories with fossil fuel use histories (a proxy for aerosol emissions) from nearby areas, they find very little correspondence. In other words, human aerosol emissions aren’t to blame for much of the solar dimming and brightening.

What may be the cause? Variations in cloud cover.

According to Stanhill and colleagues:

It is concluded that at the sites studied changes in cloud cover rather than anthropogenic aerosols emissions played the major role in determining solar dimming and brightening during the last half century and that there are reasons to suppose that these findings may have wider relevance.

Admittedly, there are only a small number of stations that were being analyzed, but Stanhill et al. have this to say:

This conclusion may be of wider significance than the very small number of sites examined in this study would suggest as the sites sampled Temperate - Maritime, Mediterranean, Continental and Tropical climates,… and covered a wide range of rates of anthropogenic aerosol emission.

The implications are that human aerosols have played a lot smaller role in the global temperature variability of the past 50 years than is generally taken to be the case. And if human aerosols are not responsible for muting the expected temperature rise from greenhouse gas emissions, then it seems that the expected rise is too much. That is, the earth’s temperature is less sensitive to rising greenhouse gas concentrations than forecasted by governmental climate models, and therefore we should expect less warming in the future.

The  second paper, published last week in Science, is yet another study trying to explain the “pause” in the rise of global average surface temperatures.  Using annual data from the University of East Anglia temperature history—the one that scientists consult the most, we are now in our 18th year without a warming trend.

(For a revealing exposé on  how even this data is being jimmied to fit the paradigm, see what just showed up in the most recent Weekend Australian.)

University of Washington’s Xianyao Chen and Ka-Kit Tung found that a naturally occurring change in ocean circulation features in the Atlantic Ocean can act to enhance or suppress the magnitude of heat that is transferred from the surface into the ocean depths. The authors find that this natural cycling was responsible for burying additional heat since the late 1990s while maintaining surface heating during the previous three decades. Coupled with earlier research (Tung and Zhou, 2013), they figure that a substantial portion (~40%) of the rise in the global surface temperatures that has occurred since the mid-20th century was caused by natural variability in the circulation of the Atlantic Ocean. 

The implication here is pretty clear—the role that human greenhouse gas emissions play in the observed warming isn’t what it was cracked up to be.  And, with a little nudge from other variables—like the sun—the quaint myth that “all scientists agree that the majority of warming since 1950 has been caused by human activity” does look more and more like another pop-up Bozo.

Taken together, the two paper combination strikes a haymaker to  the alarmist mantra—that dangerous climate change will result from greenhouse gas emissions. The Stanhill paper suggests that the projected warming wasn’t so masked by sulfate aerosols, and the Chen and Tung paper argues that less of the warming is due to a human influence anyway. This combination—greater warming pressure and less temperature change—means that the IPCC and federal climate models are just way off.

Going forward, we should expect much less human-induced global warming than government-fueled climate models project.

If this refrain sounds familiar, it is because we find ourselves frequently reporting on the subject of the earth’s climate sensitivity (how much warming results for a given input of carbon dioxide).  This issue is the biggest key to understanding anthropogenic climate change, and, because evidence continues to mount that the climate sensitivity is much less than advertised, there will be much more where this came from.

But Bozo, inflated by public monies, will spring eternal.
References

Chen, X., and K-K Tung, 2014. Varying planetary heat sink led to global-warming slowdown and acceleration. Science, 345, 897-903.

Kuhn, T. S., 1962 (and reprints).  The Structure of Scientific Revolutions.  University of Chicago Press,, 174pp.

Stanhill, G., et al., 2014. The cause of solar dimming and brightening at the Earth’s surface during the last half century: evidence from measurements of sunshine duration. Journal of Geophysical Research, doi: 10.1002/2013JD021308

Tung, K-K., and J. Zhou, 2013. Using data to attribute episodes of warming and cooling in instrumental records. Proceedings of the National Academy of Sciences, 110, 2058-2063.