climate sensitivity

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.

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.

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.

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.

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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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.

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.”

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. 

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.

Climate Insensitivity: What the IPCC Knew and Didn’t Tell Us, Part II

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.”

The bottom line from the new report from the Global Warming Policy Foundation (GWPF) is that the U.N.’s Intergovernmental Panel on Climate Change (IPCC) knew, but didn’t highlight, the fact that the best available scientific evidence suggests that the earth’s climate is much less sensitive to atmospheric carbon dioxide input than the climate models they relied upon  to forecast future global warming portray.

We covered the GWPF report and its implications in this post. But one implication is worth mentioning again, from the report’s conclusions:

The [climate models] overestimate future warming by 1.7–2 times relative to an estimate based on the best observational evidence.

While the report’s authors, Nicolas Lewis and Marcel Crok, are talking about the future, the same thing should apply to the past. In fact, a strong test of Lewis and Crok’s prediction is whether or not the same climate models predict too much warming to have already taken place than observations indicate.

There is perhaps a no better general assessment of past model behavior than the analysis that we developed for a post back in the fall.

The figure below is our primary finding. It shows how the observed rate of global warming compares with the rate of global warming projected to have occurred by the collection of climate models used by the IPCC. We performed this comparison over all time scales ranging from from 10 to 63 years. Our analysis ended in 2013 and included an analysis of the global temperature trend beginning in each year from 1950 through 2004. 

As can be clearly seen in our figure, climate models have consistently overestimated the amount of warming that has taken place. In fact, they are so bad, that over the course of the past 25 years (and even at some lengths as long as 35 years) the observed trend falls outside of the range which includes 95 percent of all model runs. In statistical parlance, this situation means that the observed trend cannot be reliably considered to be part of the collection of modeled trends. In other words, the real world is not accurately captured by the climate models—the models  predict that the world should warm up much faster than it actually does.

Climate Insensitivity: What the IPCC Knew But Didn’t Tell Us

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.”

In a remarkable example of scientific malfeasance, it has become apparent that the IPCC knew a lot more than it revealed in its 2013 climate compendium about how low the earth’s climate sensitivity is likely to be.

The importance of this revelation cannot be overstated. If the UN had played it straight, the “urgency” of global warming would have evaporated, but, recognizing that this might cause problems, they preferred to mislead the world’s policymakers.

Strong words? Judge for yourself.

The report Oversensitive—how the IPCC hid the good news on global warming,” was released today by the Global Warming Policy Foundation (GWPF)—a U.K. think-tank which is “concerned about the costs and other implications of many of the policies currently being advocated” regarding climate change (disclosure: our Dick Lindzen is a member of the GWPF Academic Advisory Council).

The new GWPF report concluded:

We believe that, due largely to the constraints the climate model-orientated IPCC process imposed, the Fifth Assessment Report failed to provide an adequate assessment of climate sensitivity – either ECS [equilibrium climate sensitivity] or TCR [transient climate response] – arguably the most important parameters in the climate discussion. In particular, it did not draw out the divergence that has emerged between ECS and TCR estimates based on the best observational evidence and those embodied in GCMs. Policymakers have thus been inadequately informed about the state of the science.

The study was authored by Nicholas Lewis and Marcel Crok. Crok is a freelance science writer from The Netherlands and Lewis, an independent climate scientist, was an author on two recent important papers regarding the determination of the earth’s equilibrium climate sensitivity (ECS)—that is, how much the earth’s average surface temperature will rise as a result of a doubling of the atmospheric concentration of carbon dioxide.

The earth’s climate sensitivity is the most important climate factor in determining how much global warming will result from our greenhouse gas emissions (primarily from burning of fossil fuels to produce, reliable, cheap energy). But, the problem is, is that we don’t know what the value of the climate sensitivity is—this makes projections of future climate change–how should we say this?–a bit speculative.

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