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climate-debate

NOAA Study: Atmosphere Warming At Half The Rate Predicted By Climate Models

by R. MCKitrick, Apr 13, 2023 in ClimateChangeDispatch

An important new study on climate change came out recently. I’m not talking about the Intergovernmental Panel on Climate Change (IPCC) Synthesis Report with its nonsensical headline, “Urgent climate action can secure a liveable future for all.”

No, that’s just meaningless sloganeering proving yet again how far the IPCC has departed from its original mission of providing objective scientific assessments. [emphasis, links added]

I’m referring instead to a new paper in the Journal of Geophysical Research-Atmospheres by a group of scientists at the U.S. National Oceanic and Atmospheric Administration (NOAA) headed by Cheng-Zhi Zou, which presents a new satellite-derived temperature record for the global troposphere (the atmospheric layer from one kilometer up to about 10 km altitude).

The troposphere climate record has been heavily debated for two reasons. First, it’s where climate models say the effect of warming due to greenhouse gases (GHGs) will be the strongest, especially in the mid-troposphere.

And since that layer is not affected by urbanization or other changes to the land surface, it’s a good place to observe a clean signal of the effect of GHGs.

Since the 1990s the records from both weather satellites and weather balloons have shown that climate models predict too much warming.

In a 2020 paper, John Christy of the University of Alabama-Huntsville (UAH) and I examined the outputs of the 38 newest climate models and compared their global tropospheric warming rates from 1979 to 2014 against observations from satellites and weather balloons.

All 38 exhibited too much warming, and in most cases, the differences were statistically significant. We argued that this points to a structural error in climate models where they respond too strongly to GHGs.

But, and this is the second point of controversy, there have also been challenges to the observational record.

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climate-debate

NOAA Confirm UAH Tropospheric Temperature Trends

by P. Homewood, Apr 13, 2023 in NotaLotofPeopleKnowThat

image

An important new study on climate change came out recently. I’m not talking about the Intergovernmental Panel on Climate Change (IPCC) Synthesis Report with its nonsensical headline “Urgent climate action can secure a liveable future for all.” No, that’s just meaningless sloganeering proving yet again how far the IPCC has departed from its original mission of providing objective scientific assessments.

I’m referring instead to a new paper in the Journal of Geophysical Research-Atmospheres by a group of scientists at the U.S. National Oceanic and Atmospheric Administration (NOAA) headed by Cheng-Zhi Zou, which presents a new satellite-derived temperature record for the global troposphere (the atmospheric layer from one kilometre up to about 10 km altitude).

The troposphere climate record has been heavily debated for two reasons. First, it’s where climate models say the effect of warming due to greenhouse gases (GHGs) will be the strongest, especially in the mid-troposphere. And since that layer is not affected by urbanization or other changes to the land surface it’s a good place to observe a clean signal of the effect of GHGs.

Since the 1990s the records from both weather satellites and weather balloons have shown that climate models predict too much warming. In a 2020 paper, John Christy of the University of Alabama-Huntsville (UAH) and I examined the outputs of the 38 newest climate models and compared their global tropospheric warming rates over 1979 to 2014 against observations from satellites and weather balloons. All 38 exhibited too much warming, and in most cases the differences were statistically significant. We argued that this points to a structural error in climate models where they respond too strongly to GHGs.

But, and this is the second point of controversy, there have also been challenges to the observational record. Christy and his co-author, Roy Spencer, invented the original method of deriving temperatures from microwave radiation measurements collected by NOAA satellites in orbit since 1979. Their achievement earned them numerous accolades, but also attracted controversy because their satellite record didn’t show any warming. About 20 years ago scientists at Remote Sensing Systems in California found a small error in their algorithm that, once corrected, did yield a warming trend.

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climate-debate

Classifying Land Temperature Stations as Either “Urban” or “Rural” in UHI Studies Proves Nothing about Spurious Temperature Trends

by Dr. Roy Spencer, Apr 5, 2023 in WUWT

From Dr. Roy Spencer’s Global Warming Blog

by Roy W. Spencer, Ph. D.

As I spend more time working on a research project, the more time I have to reflect on things that others have simply assumed to be true. And in the process I sometimes have an epiphany than clarifies my thinking on a subject.

As I continue to investigate how to quantify urban heat island (UHI) effects for the purpose of determining the extent to which land surface temperature trends have been spuriously inflated by urbanization effects, there is one recurring theme I find has not been handled well in previously published papers on the subject. I’ve mentioned it before, but it’s so important, it deserves its own (brief) blog post.

It has to do with the common assumption that “urban” thermometer sites experience spurious warming over time, while “rural” sites do not.

Obviously, at any given point in time urban environments are warmer than rural environments, especially at night. And urbanization has increased around temperature monitoring sites over the last 50 to 100 years (and longer). Yet, a number of studies over the years have curiously found that urban and rural sites have very similar temperature trends. This has led investigators to conclude that temperature datasets such as the Global Historical Climate Network (GHCN), especially after “homogenization”, is largely free of spurious warming effects from urbanization.

But the conclusion is wrong…all it shows is that temperature trends between rural and urban sites are similar… not that those trends are unaffected by urbanization effects.

Instead, studies have demonstrated that the greatest rate of warming as population increases is for nearly-rural sites, not urban. The one-fourth power relationship found by Oke (1973) and others (and which I am also finding in GHCN data in the summer) means that a population density increase from 1 to 10 persons per sq. km (both “rural”) produces more warming than an urban site going from 1,000 to 1,700 persons per sq. km.

Thus, “rural” sites cannot be assumed to be immune to spurious warming from urbanization. This means that studies that have compared “rural” to “urban” temperature trends haven’t really proved anything.

The mistake people have made is to assume that just because urban locations are warmer than rural locations at any given time that they then have a much larger spurious warming impact on trends over time. That is simply not true.

climate-debate

The State Of The Climate 2022: ‘No Reason For Alarm’

by Dr B. Pieser, Apr12, 2023 in ClimateChangeDispatch

In his annual review of the state of the global climate, Professor Ole Humlum finds much of interest to readers, but little to alarm them.

There are some climate trends that support claims of climate concern – but many that do not.

For example, Professor Humlum draws attention to the patterns of ocean warming:

“The top of most oceans shows significant warming, but below the top layer, there is very little. Further down you find warming again.

“This suggests that changes in ocean circulation are just as important as carbon-dioxide-driven warming.”

Similarly, while the surface of the Antarctic and equatorial oceans has warmed in recent years, the Arctic Ocean has cooled at almost all depths.

“There are far more factors to the climate than carbon dioxide”, says Professor Humlum.

The review covers a wide range of temperature measurements in both ocean and atmosphere, alongside reviews of oceanic oscillations, sea level, snow and ice measurements, and storms.

Ole Humlum: The State of the Climate 2022 (pdf)