Clouding the Issue of Global Warming

What’s going on with climate models?

Maybe drawing a line in the sand isn’t the best approach to climate change, especially when the sand is shifting.

A paper published in the journal “Nature Geoscience” in September theorized that the Earth might be warming a little less than climate models have predicted, by 0.3 degrees Celsius (0.54 degrees Fahrenheit).

That small number drew a lot of attention, because almost all climate scientists agree that it takes a substantial amount of emissions to warm the planet by even 0.1 degrees Celsius. If the lower estimate is correct, it would give the world more wiggle room to meet emission and warming targets.

Responses were predictable. Climate skeptics said, “All the climate models are wrong!”

“The Daily Telegraph” newspaper in Britain actually used that as a headline, “Climate models are ‘wrong.’”

Climate alarmists considered the new estimate too revisionary, and couldn’t imagine actually increasing the world’s carbon budget.

Some climate scientists noted that the new level was still at the low end of a range predicted by a group of climate models, essentially saying, “This is within the possibility of how things might go – if things go that way.”

And the general public was left thinking:

“What’s going on with these climate models?”

So it’s time to ask why there’s such a variation in climate models, and what climate scientists are doing to improve their models.

Butterfly Effect

It turns out that one of the most important factors climate scientists are now trying to understand are clouds.

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Maybe drawing a line in the sand isn’t the best approach to climate change, especially when the sand is shifting.

A paper published in the journal “Nature Geoscience” in September theorized that the Earth might be warming a little less than climate models have predicted, by 0.3 degrees Celsius (0.54 degrees Fahrenheit).

That small number drew a lot of attention, because almost all climate scientists agree that it takes a substantial amount of emissions to warm the planet by even 0.1 degrees Celsius. If the lower estimate is correct, it would give the world more wiggle room to meet emission and warming targets.

Responses were predictable. Climate skeptics said, “All the climate models are wrong!”

“The Daily Telegraph” newspaper in Britain actually used that as a headline, “Climate models are ‘wrong.’”

Climate alarmists considered the new estimate too revisionary, and couldn’t imagine actually increasing the world’s carbon budget.

Some climate scientists noted that the new level was still at the low end of a range predicted by a group of climate models, essentially saying, “This is within the possibility of how things might go – if things go that way.”

And the general public was left thinking:

“What’s going on with these climate models?”

So it’s time to ask why there’s such a variation in climate models, and what climate scientists are doing to improve their models.

Butterfly Effect

It turns out that one of the most important factors climate scientists are now trying to understand are clouds.

In fact, how clouds work and what’s going on in the deep ocean are probably the two biggest puzzles climate scientists are trying to solve.

“Every global climate model does clouds the wrong way. Some do it worse than others, but they do it wrong,” said Joel Norris, professor of climate and atmospheric sciences at the Scripps Institution of Oceanography in La Jolla, Calif., part of the University of California, San Diego.

Clouds cool the planet because they reflect sunlight back into space. They also warm the planet because they trap heat. Different kinds of clouds have different effects. And it’s hard to predict where clouds will generate in a long-range scenario.

Clouds give climate scientists the willies.

“One of the things I’ve been looking at is how clouds have been changing over years and decades,” Norris said.

That’s not a simple lab experiment, he explained. It requires monitoring equipment and other assets, like airplanes to fly into clouds. Clouds might have changed little, maybe 1 percent, but “that 1 percent actually matters a lot for how much the Earth warms,” Norris observed.

Recent observations have shown more cloud coverage shifting toward the poles and cloud tops stretching higher into the atmosphere. Norris said we have better evidence for those changes, “and if they continue as we expect, they will also matter.”

“One of the challenges (in climate science) is that things that matter happen on a small scale, and how do you represent that in a simplified way?” he said.

In current climate work, “clouds are a big part, but aerosols and how they interact with clouds are also getting a lot of study,” Norris said.

“Another big part is trying to understand how the atmospheric circulation will change and how that will affect rainfall patterns where people live,” he said, adding that there are also questions about ocean circulation, especially in the deep ocean.

“We know small things vary. And that matters,” said Andrew Gettelman, senior scientist at the National Center for Atmospheric Research in Boulder, Colo. Gettelman wrote the book “Demystifying Climate Models” with co-author Richard Rood.

Climate Model Shortcomings

“It’s hard to know if our climate models are correct. We don’t really know the current state of the atmosphere,” he said. “We can’t describe things happening in the atmosphere at the level of detail we need.”

Climate models begin with the same approach as models used for short-term weather forecasting. In weather prediction, getting the large-scale motions of the atmosphere right is the critical step, Norris said. Climate prediction presents a more complex challenge on a time-scale of decades.

So why trust climate models at all?

“The advantage is, we know what the energy balance is. We have these large-scale constraints for climate modeling, which we don’t have for weather modeling,” Gettelman noted. “Those large-scale constraints help us because we can add up all the elements in the system.”

“My ultimate philosophy of climate modeling is, you constrain every aspect of the model to be realistic. The foundation is the fundamental laws of physics. We don’t violate any of them,” he said.

Norris, who isn’t a climate modeler himself, thinks there are limits to the usefulness of climate models.

“Climate models have been popular, but I don’t know in the big scope of things how much we’ve learned from them,” he explained.

“The way I look at them is, they’re a useful tool,” Norris said. “Climate models are better for analyzing processes, and not for getting a quantitatively precise answer.”

Predicting and Shaping the Future

It’s time for some definitions and background:

A “climate model” is a set of equations designed to approximate the workings of the Earth’s climate system in a simplified way. Still, climate models can be complex, sometimes requiring a supercomputer to process.

An “ensemble” is a selected group of climate models. No single climate model is likely to mirror the Earth’s climate system exactly, so scientists use an ensemble to produce a range of possible outcomes.

A “forcing” is a factor that affects climate. Positive forcing makes the planet warmer; negative forcing makes it cooler.

The troposphere is the lowest region of the atmosphere, extending up about 10 kilometers from the Earth’s surface.

The Paris Climate Accord was negotiated in 2015 by 195 nations plus the European Union. A goal of the accord is “holding the increase in the global average temperature to well below 2 degrees C above pre-industrial levels, and to pursue efforts to limit the temperature increase to 1.5 degrees C.”

If you want to run a climate model for future decades, you have to make assumptions about processes and inputs. You’ll need to make projections. How many volcanoes will erupt in the next 30 years, and how much ash will enter the atmosphere? How will cloud formations emerge, and where?

While it is possible the climate models themselves are badly flawed, it’s more likely that the assumptions have been far enough off to cause a miscalculation of projected warming – not by degrees or even a single degree, but by a fraction of a degree.

And that’s exactly what the authors said in the “Nature Geoscience” paper, published online as “Emission budgets and pathways consistent with limiting warming to 1.5 degrees C.” The paper was written by Richard Millar of the Environmental Change Institute at the University of Oxford, with nine co-authors.

The new, 0.3 degree Celsius-lower estimate of warming seemed to take everyone by surprise. It probably shouldn’t have. Dozens of papers have appeared in the scientific literature that address the climate models’ overestimation of warming.

In June, the very same journal included a paper titled “Causes of differences in model and satellite tropospheric warming rates,” by Benjamin Santer of the Lawrence Livermore National Laboratory and 15 co-authors, including climatologist Michael Mann.

“In the early 21st century, satellite-derived tropospheric warming trends were generally smaller than trends estimated from a large multi-model ensemble,” the authors noted.

“We conclude that model overestimation of tropospheric warming in the early 21st century is partly due to systematic deficiencies in some of the post-2000 external forcings used in the model simulations,” they wrote.

Climate scientists will be debating the latest findings for years. The bottom line is there’s a belief out there right now that the planet has warmed a little less than scientists had expected.

And that’s a good thing.

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Comments (7)

Climate "models" possess intrisic flaws
Models: I have no issue with models, per se. I use them in my own work (seismic interpretation). Some models are decent; some are not decent. As the complexity rises, the model tends to be more problematic (read: "less accurate"). Climate "models" are attempting to model a coupled, non-linear, dynamic system (and systems engineers will tell you that this is well-nigh impossible, over any time duration greater than a few seconds). Forecasts, predictions, scenarios (or whatever the favored buzzword of the day is) based on these models will be nonsense. This is flaw number one. The bigger flaw in climate "models" is the expressed or implied belief that carbon dioxide, a small trace gas in Earth's atmosphere, is able to control the overall temperature of the planet. Anyone who examines the history of the Earth will know, temperature and atmospheric carbon dioxide concentration are independent of each other. As long as groups such as the IPCC and their minions persist in the assumption that carbon dioxide is the "thermostat" of the Earth's atmosphere, their vaunted "models" will continue to be wrong, and not just by a few, " ... tenths of a [Celsius] degree ... ". I accept that the Earth's climate is changing; since it always has, and always will, it would be foolish to attempt to believe otherwise. I completely reject that human-kind are responsible for even a fraction-of-a-Kelvin change in temperature, at any point in time or history. It is the height of hubris to believe we have that power. Mark Hladik, Consulting Geophysicist, Casper, Wyoming
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4/2/2018 10:50:53 AM
CO2 as warming agent
Believing that by controlling CO2 emissions we can influence the overwhelming climate drivers like solar irradiance may satisfy the human ego but almost nothing beyond that. Because, a large storehouse of analyses, anthropological and geological records prove that human impact on the overall temperature at the global scale is minimal. One needs to ask these questions to the alarmists. I. Are there evidences of earth warming up and cooling down in the geological past? II. Did that happen before the humans came into being? III. Did we experience a period much warmer than what it is now with or without CO2? IV. Don't we see on a map the huge scatter of onland oilfields producing from ancient marine deposits confirming the sea invaded the land time and again before humans came? After bringing down the CO2 emissions by a fraction through years of painstaking efforts we may find an eruption in the Krakatoa volcano pumping tons of CO2 back into the atmosphere. The principal causes of warming and cooling are sun's activity and ocean currents. Rather than embarking on the impossible task of disciplining the sun and the seas at a huge cost, it would be easier and better to clean up the earth from anthropogenic pollution and adapt to the changing climates.
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4/2/2018 5:41:26 AM
What are the most critical components of Global Warming (as per Dr Neal Frank, Meteorologist, former Director of the NHC).
As a professional scientist I try to always keep an open mind and use multiple working hypotheses in deciding on what or who to believe regarding Global Warming. I came across a very interesting presentation regarding Global Warming and CO2 by Dr Neal Frank. Dr Frank's presentation names many important scientist who do not see CO2 as a major component of GW. These senior scientist tell how they were pressured into agreeing with CO2 being a major GHG, when they did not agree with this. These are top high profile scientist such as the founder of Green Peace, Dr Patrick Moore who dropped out of Green Peace due to being a skeptic of CO2 -- Dr Jay Lehr founder of the EPA, Dr Alan Carl -- big supporter of Sierra Club who has written a book after seeing MIT data in 2006 which disputes the role of CO2 ( his book is "Environmentalist Gone Mad"). There are many other top notch scientist, and Dr Frank does a great job of presenting the science 1st, then the politics and quotes from people who are trying to drive the CO2 argument. I try to keep an open mind, but Dr Franks presentation is very compelling. Watch his 42 minute presentation and make up your own mind. I sure did.There are many prominent 'skeptics' of CO2 who believe the CO2 argument is being corrupted by big government, not by science data. In summary, I recommend taking the time to watch Dr Neal Frank's GW presentation which disputes the CO2 story which he believes is being driven by politics and big $$$$, not science. I say, just keep an open mind and use multiple working hypotheses, Regards. https://www.youtube.com/watch?v=LVkUKNOPI3g
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3/31/2018 12:00:00 PM
Climate Modeling
For the reviewer to summarize the "Nature Geoscience" paper by saying "...there’s a belief out there right now that the planet has warmed a little less than scientists had expected..." misses the larger point. In November 2016, Rosenbaum at Caltech posited that nature cannot be modeled with classical physics but theoretically might be modeled with quantum physics. (http://www.caltech.edu/news/caltech-next-125-years-53702) In the article “Global atmospheric particle formation from CERN CLOUD measurements,” sciencemag.org, 49 authors concluded “Atmospheric aerosol nucleation has been studied for over 20 years, but the difficulty of performing laboratory nucleation-rate measurements close to atmospheric conditions means that global model simulations have not been directly based on experimental data….. The CERN CLOUD measurements are the most comprehensive laboratory measurements of aerosol nucleation rates so far achieved, and the only measurements under conditions equivalent to the free and upper troposphere.” (December 2, 2016, volume 354, Issue 6316) The article emphasizes the importance of replacing theoretical calculations in models with laboratory measurements. I have found no discussion of whether earth systems can or cannot be modeled with Newtonian physics in IPCC releases or in the mass media. A "belief" that the planet has warmed a little less than scientists had expected seems irrelevant to me. The bigger issues are whether the long-term climate of the planet will be warmer or colder than present and will any policies make a positive difference. Science my never answer these questions.
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3/31/2018 11:51:55 AM
Climate Models
A big problem is climate models are used as data in climate change politics. Models need to be tested and discarded if there is a poor fit to real temperature data. Satellite temperature data show no warming for the past 20 years despite increasing atmospheric C02 and no climate model fits these data.
3/31/2018 10:23:04 AM
Essential Uncertainty in Predicting Global warming
Dear David, Thanks for sharing this finding. I do not think that many Geoscientists would be surprised at the 0.3 deg C deviation from prediction. We practitioners of the craft of exploration know within our guts the essential probabilistic nature of predicting exploration outcomes. The IPCC models, e.g. *(ref. link below) also clearly capture the range of variations in the predicted outcomes. However, the presentation of the outcomes of models to the general public appears to be more certain and gives the perception that there is more certainty in the models. It is not uncommon to see news items that say, "The temperature will rise by X Deg C and that the sea will rise by Y m in the period of Z years". As scientists we need to emphasise the probabilistic nature of our predictions more effectively. Otherwise we face the danger of losing our credibility with general public. Bala Kunjan 31st March 2018 *https://www.ipcc.ch/publications_and_data/ar4/wg1/en/spmsspm-projections-of.html
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3/30/2018 8:57:40 PM
climate modeling
All models are wrong, some are useful. The problem arises not from models but policies being set by models. Few modelers ever provide feedback when one does a look back at the their model from 10 years ago and how wrong it was but at the time they fully believed that it was the best.
11/8/2017 10:54:18 AM

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