Occasional Thoughts on Climate Change

[ChescoWx]

Imagine if we could actually see the actual real raw US average temperature trend? 

[donsutherland1]

33 minutes ago, ChescoWx said:

Imagine if we could actually see the actual real raw US average temperature trend? 

For purposes of illustration, below is an example of why Shewchuk's arguments are deeply flawed. The illustration examines the change in Phoenix's mean summer minimum temperatures.

Shewchuk's dismissal of adjusted data would mean that Phoenix's climate has seen summer minimum temperatures increase almost 1.5° per decade due to climate change (natural and anthropogenic). His claims would ignore the impact that the emergence and then rapid growth of Phoenix's Urban Heat Island Effect has had on summer minimum temperatures. In 1941, the beginning of the first 30-year period under consideration, Phoenix had a population of just over 65,000. In 2024, Phoenix's population was 1,682,515.  During 1940-1980, Phoenix's population grew an average of 6.4% per year; since 1980, it has been growing at about 1.8% per year. The sharper rise in the raw data during the first part of the chart and flattening afterward provide a footprint of the growth in the UHI.

If one were seeking to understand how fast Phoenix's climate has been warming, one would need to exclude artificial factors e.g., UHI. That's what the adjustments do. They remove the impacts of siting changes (location, features such as new buildings, etc.), UHI, time of observation bias, etc. The adjustments allow for comparability. They make robust scientific analysis possible. 

[LibertyBell]

15 hours ago, TheClimateChanger said:

July is warming by as much as 5 or 6 degrees per century, which is substantially less. However, the latitudinal variance is considerably less, so that's possibly an even bigger shift in terms of latitude. Will everyone east of the Mississippi have a South Carolina low country climate by 2100? Will the Southeast turn into a blazing inferno of deadly wet bulb events?

Yes, the farther north you go the faster the warming.  Boston has many many more 100 degree days than NYC in the last 12-13 years.  Even Burlington is hotter.  The lobsters are also migrating north, they used to have a colony near Long Island, which migrated to Maine which is now going even farther north to the Maritime Provinces.

[LibertyBell]

48 minutes ago, donsutherland1 said:

For purposes of illustration, below is an example of why Shewchuk's arguments are deeply flawed. The illustration examines the change in Phoenix's mean summer minimum temperatures.

Shewchuk's dismissal of adjusted data would mean that Phoenix's climate has seen summer minimum temperatures increase almost 1.5° per decade due to climate change (natural and anthropogenic). His claims would ignore the impact that the emergence and then rapid growth of Phoenix's Urban Heat Island Effect has had on summer minimum temperatures. In 1941, the beginning of the first 30-year period under consideration, Phoenix had a population of just over 65,000. In 2024, Phoenix's population was 1,682,515.  During 1940-1980, Phoenix's population grew an average of 6.4% per year; since 1980, it has been growing at about 1.8% per year. The sharper rise in the raw data during the first part of the chart and flattening afterward provide a footprint of the growth in the UHI.

If one were seeking to understand how fast Phoenix's climate has been warming, one would need to exclude artificial factors e.g., UHI. That's what the adjustments do. They remove the impacts of siting changes (location, features such as new buildings, etc.), UHI, time of observation bias, etc. The adjustments allow for comparability. They make robust scientific analysis possible. 

Phoenix has set some absolutely amazing records the last few years and not just for one or two days but for the entire summer, Don!

[donsutherland1]

1 minute ago, LibertyBell said:

Phoenix has set some absolutely amazing records the last few years and not just for one or two days but for the entire summer, Don!

That’s true. With summers continuing to warm, there has been a sudden explosion of truly extreme summers. It’s too soon to draw too many conclusions about that, but in general extremes have increased in a non-linear fashion as the climate has warmed.

[TheClimateChanger]

1 hour ago, donsutherland1 said:

For purposes of illustration, below is an example of why Shewchuk's arguments are deeply flawed. The illustration examines the change in Phoenix's mean summer minimum temperatures.

Shewchuk's dismissal of adjusted data would mean that Phoenix's climate has seen summer minimum temperatures increase almost 1.5° per decade due to climate change (natural and anthropogenic). His claims would ignore the impact that the emergence and then rapid growth of Phoenix's Urban Heat Island Effect has had on summer minimum temperatures. In 1941, the beginning of the first 30-year period under consideration, Phoenix had a population of just over 65,000. In 2024, Phoenix's population was 1,682,515.  During 1940-1980, Phoenix's population grew an average of 6.4% per year; since 1980, it has been growing at about 1.8% per year. The sharper rise in the raw data during the first part of the chart and flattening afterward provide a footprint of the growth in the UHI.

If one were seeking to understand how fast Phoenix's climate has been warming, one would need to exclude artificial factors e.g., UHI. That's what the adjustments do. They remove the impacts of siting changes (location, features such as new buildings, etc.), UHI, time of observation bias, etc. The adjustments allow for comparability. They make robust scientific analysis possible. 

Don, I would also question the replicability of Shewchuk's graph, especially in recent years. I see no evidence of recent years being adjusted upwards, so that weird pause since 1998 makes zero sense. There have been plenty of recent years that have far exceeded 1998 (2012, 2023, 2024, etc.). It is worth pointing out that the redundant, higher quality CRN network was established in 2005 and shows slightly more warming than nClimDiv during the period of overlap. There is no evidence to suggest that recent data is being adjusted upwards.

Looking at the rest of the graph, the magnitude of adjustments for TOBs and instrument changes looks to be of a reasonable magnitude. I know sometimes these graphics are manipulated by not factoring in gridding / proper areal averaging, which isn't an adjustment within the meaning of that term. Another common misrepresentation is to show only maximum temperature data. The MMTS bias adjustment is to lower older daytime maxima; however, the bias adjustment raises older minima. The net affect of these offsetting adjustments is negligable to Tavg trend. Here, it looks like Shewchuk uses Tavg, so I will say it doesn't appear to be as misleading as some of the stuff I have seen Heller and Martz publish.

He does cutoff the analysis at 1925, because prior to that date [back to 1895], adjustments are minimal and I think it would ruin the presentation he wants to give that the warming results only from adjustments. Also, as I said previously, the recent data definitely looks off. Doesn't seem to jive with actual observations. Without that weird sudden dropoff post-1998 in the so-called "raw" data, the trends since 1960 would be quite similar in both the so-called "raw" and "altered" data.

 

[ChescoWx]

57 minutes ago, donsutherland1 said:

That’s true. With summers continuing to warm, there has been a sudden explosion of truly extreme summers. It’s too soon to draw too many conclusions about that, but in general extremes have increased in a non-linear fashion as the climate has warmed.

Heck we might eventually get a warm as we were back in the 1930's in our current cyclical warming cycle.....

[TheClimateChanger]

2 minutes ago, ChescoWx said:

Heck we might eventually get a warm as we were back in the 1930's in our current cyclical warming cycle.....

Interesting. @donsutherland1, do you find any evidence of a cyclical warming in the Phoenix data? Were the 1930s even hotter there, as seems to be insinuated here?

[donsutherland1]

9 minutes ago, TheClimateChanger said:

Don, I would also question the replicability of Shewchuk's graph, especially in recent years. I see no evidence of recent years being adjusted upwards, so that weird pause since 1998 makes zero sense. There have been plenty of recent years that have far exceeded 1998 (2012, 2023, 2024, etc.). It is worth pointing out that the redundant, higher quality CRN network was established in 2005 and shows slightly more warming than nClimDiv during the period of overlap. There is no evidence to suggest that recent data is being adjusted upwards.

Looking at the rest of the graph, the magnitude of adjustments for TOBs and instrument changes looks to be of a reasonable magnitude. I know sometimes these graphics are manipulated by not factoring in gridding / proper areal averaging, which isn't an adjustment within the meaning of that term. Another common misrepresentation is to show only maximum temperature data. The MMTS bias adjustment is to lower older daytime maxima; however, the bias adjustment raises older minima. The net affect of these offsetting adjustments is negligable to Tavg trend. Here, it looks like Shewchuk uses Tavg, so I will say it doesn't appear to be as misleading as some of the stuff I have seen Heller and Martz publish.

He does cutoff the analysis at 1925, because prior to that date [back to 1895], adjustments are minimal and I think it would ruin the presentation he wants to give that the warming results only from adjustments. Also, as I said previously, the recent data definitely looks off. Doesn't seem to jive with actual observations. Without that weird sudden dropoff post-1998 in the so-called "raw" data, the trends since 1960 would be quite similar in both the so-called "raw" and "altered" data.

 

I'm not sure where he gets some of his data from. Yes, the USCRN data debunks his claims. 

[ChescoWx]

7 minutes ago, TheClimateChanger said:

Interesting. @donsutherland1, do you find any evidence of a cyclical warming in the Phoenix data? Were the 1930s even hotter there, as seems to be insinuated here?

@TheClimateChangerlet me help you our with a broader view of the entire USA.....say hey to the 1930's!

[TheClimateChanger]

As an aside, I find it hilariously hypocritical that @ChescoWx's signature complains about the use of the word "denier." He bandies that term around more than anyone here... calling people natural climate change deniers and cyclical climate change deniers. 

[ChescoWx]

Pittsburgh like so many others spots including Chester County...let's just cool those pesky 1930's and 1940's ...it always gives us the answers we want....

 

[ChescoWx]

1 minute ago, TheClimateChanger said:

As an aside, I find it hilariously hypocritical that @ChescoWx's signature complains about the use of the word "denier." He bandies that term around more than anyone here... calling people natural climate change deniers and cyclical climate change deniers. 

I've matured and removed the word from my vocabulary.....LOL!!

[donsutherland1]

11 minutes ago, TheClimateChanger said:

Interesting. @donsutherland1, do you find any evidence of a cyclical warming in the Phoenix data? Were the 1930s even hotter there, as seems to be insinuated here?

At best, there is a hint of an uncertain weak cyclical effect. However, changes in aerosols may well have driven most of the cooling seen in the 1960s. In any case, strong and persistent warming from UHI + anthropogenic climate change have overwhelmed any periodicity that might exist in Phoenix. The warmest summer during the 1930s was 1933 with a mean of 91.7° and the warmest year during the 1930s was 1934 with a mean of 74.2°. Every summer and every year since 2000 has exceeded those figures. The last cooler summer was 1999 and the last cooler year was 1998.

[TheClimateChanger]

2 minutes ago, ChescoWx said:

Pittsburgh like so many others spots including Chester County...let's just cool those pesky 1930's and 1940's ...it always gives us the answers we want....

 

Lol. There was no "Greater Pittsburgh Air Force Base" with data back to 1880. What a clown. This appears to be a mix & match of different stations threaded together. In fact, it looks to be the official station thread. Funny it cuts off in 2020. Even the airport [400+ feet higher in elevation] beat any year in history by 1F just last year.

[donsutherland1]

27 minutes ago, ChescoWx said:

Heck we might eventually get a warm as we were back in the 1930's in our current cyclical warming cycle.....

Setting aside extreme maximum temperatures in the area most affected by the Dust Bowl, on a nationwide basis, such summers have already been matched or exceeded. Only 136 retains the top spot (in a tie).

[ChescoWx]

Who can spot the UHI chilling adjustments done to the PHL Airport data?? Hmmm I guess there is no UHI amidst the runways and jet exhaust....

[TheClimateChanger]

4 minutes ago, ChescoWx said:

Who can spot the UHI chilling adjustments done to the PHL Airport data?? Hmmm I guess there is no UHI amidst the runways and jet exhaust....

It looks like they did adjust the trend down. Rather than chill recent years, early years appear to be adjusted upwards, no? Pretty substantially in the 1960s and 70s, in fact. What am I missing here? The unadjusted data pretty clearly shows a steeper warming trend than the adjusted data.

[ChescoWx]

Who can spot that same chilling of the past data in the SE Pittsburgh Burbs?? Do we see a pattern chill the past!!

[ChescoWx]

1 minute ago, TheClimateChanger said:

It looks like they did adjust the trend down. Rather than chill recent years, early years appear to be adjusted upwards, no? Pretty substantially in the 1960s and 70s, in fact. What am I missing here? The unadjusted data pretty clearly shows a steeper warming trend than the adjusted data.

Where's the chilling for the recent years ongoing UHI problems at PHL???

[ChescoWx]

The Queen City in Ohio joins the altered past climate group.....there really is a pattern here!

[TheClimateChanger]

37 minutes ago, ChescoWx said:

The Queen City in Ohio joins the altered past climate group.....there really is a pattern here!

There was no Cincinnati WSO until nearly 2000 - much of that appears to be made up "ghosted" data as you have referred to it in the past. For the period where there actually is data [i.e., up until the 1960s & 1970s], the adjusted & homogenized final product appears to decrease the trend. Moreover, this is a rooftop urban station. In recent years, temperatures at the airport - several hundred feet higher in elevation, with an aspirated temperature sensor, sited over grass - have exceeded even those lofty early years.

Here's what the site looked like in 1947 (see illustration below). I would 100% favor bringing back these stations today and actually reporting the observed temperatures. Guarantee they would be far warmer than whatever is shown on there.

 

[ChescoWx]

4 minutes ago, TheClimateChanger said:

There was no Cincinnati WSO until nearly 2000 - much of that appears to be made up "ghosted" data as you have referred to it in the past. For the period where there actually is data [i.e., up until the 1960s & 1970s], the adjusted & homogenized final product appears to decrease the trend. Moreover, this is a rooftop urban station. In recent years, temperatures at the airport - several hundred feet higher in elevation, with an aspirated temperature sensor, sited over grass - have exceeded even those lofty early years.

Here's what the site looked like in 1947 (see illustration below). I would 100% favor bringing back these stations today and actually reporting the observed temperatures. Guarantee they would be far warmer than whatever is shown on there.

 

It's all ghosted fake data - no doubt that adjusted data is exacty what they use on CinCin TV networks to show their man made "warming" climate

[TheClimateChanger]

1 minute ago, ChescoWx said:

It's all ghosted fake data - no doubt that adjusted data is exacty what they use on CinCin TV networks to show their man made "warming" climate

Meh, most of what's called adjustments is actually just areal averaging/gridding of the data. With states like Ohio or Illinois, where there aren't huge variations in elevation, and the stations have been pretty well separated throughout history, there's little discrepancy in the pre-1920 data versus what NCEI reports. There's a small decrease to account for observation time, and adjustment for instrument bias, from about the 1920s gradually decreasing in the 1960s to 1970s. Recent decades are generally slightly less. Why - I'm not sure, I guess a small negative UHI adjustment. Obviously, looking at individual sites, there can be significantly larger inhomogeneities - especially with some of them that have been shuttered and/or threaded with a bunch of disparate locations, elevations and site exposures.

[TheClimateChanger]

6 minutes ago, TheClimateChanger said:

Meh, most of what's called adjustments is actually just areal averaging/gridding of the data. With states like Ohio or Illinois, where there aren't huge variations in elevation, and the stations have been pretty well separated throughout history, there's little discrepancy in the pre-1920 data versus what NCEI reports. There's a small decrease to account for observation time, and adjustment for instrument bias, from about the 1920s gradually decreasing in the 1960s to 1970s. Recent decades are generally slightly less. Why - I'm not sure, I guess a small negative UHI adjustment. Obviously, looking at individual sites, there can be significantly larger inhomogeneities - especially with some of them that have been shuttered and/or threaded with a bunch of disparate locations, elevations and site exposures.

Here is the average of all available data in Ohio for July 1895:

The reported value for that month is 71.1F, just 0.1F different than a simple average of the data. This is not the case for states with more significant elevation changes. Generally, the early data is devoid or limited of high elevation stations, so the simple average is often much higher than the gridded average. But most of the data for the Midwest matches pretty close to the reported data - like I said there are some adjustments made to later decades, but these are reasonable (change in TOBs and instruments). Ideally, we would have just maintained the 5 pm / 6 pm observations and CRS readings, and then there would be no need for any adjustments. But unfortunately, we don't live in the universe where those changes weren't made. I think it is reasonable to consider whether maybe to reinstate them at certain or all sites?

 

[TheClimateChanger]

For comparison, July 2020. Simple arithmetic mean of 99 stations: 77.1F. NCEI reports 76.9F, or 0.2F cooler. If they are conducting some sort of massive increase in recent temperatures, they seem to be omitting the Midwest from the warming. To be honest, the earlier sample has a much greater proportion of center city and rooftop sites, with all of the city observations moved out to suburban airports and the city WSOs closed. So it's actually kind of surprising, there's no deviation from the simple mean, because there are clearly non-climatic biases in the data.

 

[bdgwx]

Over their mutual overlap period from 2005/01 to 2025/05...

+0.65 F.decade-1 is the warming trend using nClimDiv (formerly USHCN).

+0.77 F-decade-1 is the warming trend using USCRN.

Considering that nClimDiv should have a more significant UHI component than that of USCRN it would not be unreasonable to hypothesize that it is underestimating the warming in the United States more than the trivial difference would already imply.

I'll also remind readers here of what the net effect of all adjustments at the global level.

[Hausfather 2017]

[bdgwx]

9 hours ago, donsutherland1 said:

For purposes of illustration, below is an example of why Shewchuk's arguments are deeply flawed.

Several years ago Shewchuck told me that he has testified in court as meteorological expert using only raw data because his worldview is that you should never apply corrections to fix biases, errors, and/or mistakes. When I asked if he discloses to the court that the data may contain biases, errors, and/or mistakes the conversation ended immediately and he ghosted me.

I think at some level contrarians have to know that what they are arguing for is at best unethical and potentially fraudulent with criminal consequences at worst. It makes it even that more baffling that they continue down this line of argument while simultaneously gaslighting the rest of us as if we're in the wrong.

[A-L-E-K]

11 hours ago, bdgwx said:

Several years ago Shewchuck told me that he has testified in court as meteorological expert using only raw data because his worldview is that you should never apply corrections to fix biases, errors, and/or mistakes. When I asked if he discloses to the court that the data may contain biases, errors, and/or mistakes the conversation ended immediately and he ghosted me.

I think at some level contrarians have to know that what they are arguing for is at best unethical and potentially fraudulent with criminal consequences at worst. It makes it even that more baffling that they continue down this line of argument while simultaneously gaslighting the rest of us as if we're in the wrong.

They're getting rich, hope this helps