Phoenix Records its Hottest Summer on Record

[donsutherland1]

Phoenix concluded, by far, its hottest summer on record. During June-August 2020, Phoenix had a mean temperature of 96.7°. That smashed the old record of 95.1°, which was set in 2013 and tied in 2015.

Table 1: Summer 2020 Average Temperatures

Since 2009, every summer has ranked among the 20 warmest summers on record. In addition, 2015, 2016, 2019 and 2020 have ranked among the 10 warmest summers.

Table 2: 20 Warmest Summers

Monthly Mean Temperatures:
June: 92.0° (21st warmest June on record)
July: 98.9° (warmest July on record; old record: 98.3°, 2009)
August: 99.1° (warmest August on record; old record: 98.3°, 2011)

July 2020 set a new monthly mean temperature. August 2020 surpassed that record.

Just 3 (15%) of the 20 warmest months were recorded prior to 2000. 17 (85%) of the warmest months occurred 2000 or later and 10 (50%) of the warmest months occurred 2010 or later.

There were three cases where both July and August ranked among the 20 warmest months: 2007, 2019 and 2020.

Table 3: 20 Warmest Months

Table 4: Record High Minimum Temperatures

Table 5: Record High Maximum Temperatures

Select Monthly Heat Thresholds:
Highs 110° or above: 22 days, August 2020 (old record: 19 days, July 2020; prior old record: 18 days, June 1974)
Highs 115° or above: 7 days, August 2020 (tied record set in June 1974)
Lows: 90° or above: 16 days, July 2020 (old record: 11 days, July 2006); August 2020 had 12 such days.  

Select Summer Heat Thresholds:
Highs 110° or above: 48 days (old record: 31 days, 2007 and 2011)
Highs 115° or above: 13 days (old record: 7 days, 1974)
Lows: 90° or above: 28 days (old record: 15 days, 2003 and 2013)  

Climate Change:

Anthropogenic climate change is driving a warming of Phoenix's summers. The warming has accelerated in recent decades. The observed global warming since the 1950s is unequivocal with anthropogenic greenhouse gas emissions being the dominant driver of that warming (IPCC Climate Change Synthesis Report 2014). The warming is a global phenomenon with 98% of the world having experienced its warmest 51 years during the current 2,000 years (Neukom, et al. 2019).

Recent research suggests that Phoenix's climate will resemble that of Baghdad by 2050 (Bastin, et al. 2019). During the summer, Baghdad typically receives no rainfall. Baghdad's average high temperatures (Weather Atlas 2002-2020) during the summer months are:

June: 105.8°
July: 111.2°
August: 109.4°

Summer Average High Temperature: 108.8°

Until summer 2020, the highest mean summer maximum temperature was 107.0°, which was set in 1978 and tied in 1989. The highest monthly summer maximum temperature was 109.8°, which was set in July 1989 and tied in July 2020. August 2020 surpassed that record with an average high temperature of 110.7°.

As recently as 2000, Phoenix's average low temperature during the summer was 79.8°. Since 1999, Phoenix has had no summer with an average low temperature below 80.0°. Prior to 2020, the highest average monthly minimum temperature was 87.5°, which was set in August 2011. July 2020 had an average minimum temperature of 88.0°.

Based on the above research findings, summer 2020 provides a glimpse of what a typical Phoenix summer will be like by 2050.

Table 6: Average Summer Temperatures (30-Year Moving Average)

Climate change is also resulting in an increase in the frequency of days on which the low temperature stays at or above 90° and the high temperature reaches 100° or above, 110° or above, and 115° or above.

Table 7: Average Annual Days at Set Thresholds (30-Year Moving Average)

According to the Fourth National Climate Assessment, Phoenix saw 60 to nearly 100 100° days per year at the 5th and 95th percentiles. Under the RCP 4.5 scenario, those figures are projected to increase to 110-141 days per year during the 2070-2099 period. During the 1950-1999 period, 9 (18%) of years saw the number of 100° days fall within the projected RCP 4.5 interval (U.S. Global Change Research Program, 2017). From 2000-2019, 11 (55%) of years fell within that interval. 2020 is all but certain to become the 12th case since 2000 to meet that higher interval. Moreover, through August 31, the 30-year moving average is just above 110 days per year.

During the summer, 48 days saw high temperatures 110° or above. The previous summer record was 31 days, which was set in 2007 and tied in 2011. During 2020, there have been 50 such days vs. the prior record of 33 days, which was set in 2011. There were also 28 days on which the minimum temperature was 90° or above, which eclipsed the previous record of 15, which was set in 2003 and tied in 2013.

In addition, the number of very hot (high temperature of 110° or above) and super hot (high temperature of 115° or above) days has been increasing as a share of the increasing number of 100° days. For the 30-year period ending in 1980, 12.6% of 100° days had high temperatures of 110° or above and 1.0% saw temperatures reach 115° or above. For the 30-year period ending in 2000, those figures increased to 15.7% and 1.7% respectively. For the period ending in 2020 (through August 31), those figures increased further to 18.8% and 2.0% respectively.

Overall, the frequency and intensity of compound summertime hot extremes (events that combine daytime and nighttime heat where such temperatures are above their 90th percentile for their calendar) has been increasing especially in geographic locations that include the U.S. Southwest (Wang 2020). The increase in forcing associated with anthropogenic greenhouse gases is the dominant driver of this outcome. (Wang 2020). During summer 2020, 15 record high minimum temperatures were tied or broken in Phoenix and 14 record high maximum temperatures were tied or broken. On 7 days, both record high minimum and maximum temperatures were tied or broken.

Summary:

Summer 2020 saw Phoenix record its highest summer temperature on record. It also saw Phoenix experience its two hottest months on record. In addition, Phoenix easily surpassed records for the most days on which the temperature reached 110° or above and on which minimum temperature was 90° or higher.  

Anthropogenic climate change, which has turned hot patterns hotter and increased pattern persistence, is largely responsible for this exceptional warmth. Based on the latest research, the extreme heat of summer 2020 will likely become the "new normal" by 2050.

Updates:

September 1-7: https://www.americanwx.com/bb/topic/53697-phoenix-records-its-hottest-summer-on-record/?do=findComment&comment=5650331

Summer High Temperatures: Climate Model Projections and Actual Outcomes: https://www.americanwx.com/bb/topic/53697-phoenix-records-its-hottest-summer-on-record/?do=findComment&comment=5661632

Phoenix Records a 90° Mean Temperature for September: https://www.americanwx.com/bb/topic/53697-phoenix-records-its-hottest-summer-on-record/?do=findComment&comment=5664607

Phoenix Experiences its Hottest Week in October: https://www.americanwx.com/bb/topic/53697-phoenix-records-its-hottest-summer-on-record/?do=findComment&comment=5668129

Phoenix Sets New Annual Record for 100° Days: https://www.americanwx.com/bb/topic/53697-phoenix-records-its-hottest-summer-on-record/?do=findComment&comment=5672012

A Very Warm October Concludes in Phoenix: https://www.americanwx.com/bb/topic/53697-phoenix-records-its-hottest-summer-on-record/?do=findComment&comment=5684211

Phoenix Experiences its Warmest 5-Day November Period on Record: https://www.americanwx.com/bb/topic/53697-phoenix-records-its-hottest-summer-on-record/?do=findComment&comment=5687553

Phoenix Experiences Latest 90° Days on Record: https://www.americanwx.com/bb/topic/53697-phoenix-records-its-hottest-summer-on-record/?do=findComment&comment=5698629

 

 

 

 

[Bhs1975]

Phoenix concluded, by far, its hottest summer on record. During June-August 2020, Phoenix had a mean temperature of 96.7°. That smashed the old record of 95.1°, which was set in 2013 and tied in 2015.

Table 1: Summer 2020 Average Temperatures

Since 2009, every summer has ranked among the 20 warmest summers on record. In addition, 2015, 2016, 2019 and 2020 have ranked among the 10 warmest summers.

Table 2: 20 Warmest Summers

Monthly Mean Temperatures:

June: 92.0° (21st warmest June on record)

July: 98.9° (warmest July on record; old record: 98.3°, 2009)

August: 99.1° (warmest August on record; old record: 98.3°, 2011)

July 2020 set a new monthly mean temperature. August 2020 surpassed that record.

Just 3 (15%) of the 20 warmest months were recorded prior to 2000. 17 (85%) of the warmest months occurred 2000 or later and 10 (50%) of the warmest months occurred 2010 or later.

There were three cases where both July and August ranked among the 20 warmest months: 2007, 2019 and 2020.

Table 3: 20 Warmest Months

Table 4: Record High Minimum Temperatures

Table 5: Record High Maximum Temperatures

Select Monthly Heat Thresholds:

Highs 110° or above: 22 days, August 2020 (old record: 19 days, July 2020; prior old record: 18 days, June 1974)

Highs 115° or above: 7 days, August 2020 (tied record set in June 1974)

Lows: 90° or above: 16 days, July 2020 (old record: 11 days, July 2006); August 2020 had 12 such days.  

Select Summer Heat Thresholds:

Highs 110° or above: 48 days (old record: 31 days, 2007 and 2011)

Highs 115° or above: 13 days (old record: 7 days, 1974)

Lows: 90° or above: 28 days (old record: 15 days, 2003 and 2013)  

Climate Change:

Anthropogenic climate change is driving a warming of Phoenix's summers. The warming has accelerated in recent decades. The observed global warming since the 1950s is unequivocal with anthropogenic greenhouse gas emissions being the dominant driver of that warming (IPCC Climate Change Synthesis Report 2014). The warming is a global phenomenon with 98% of the world having experienced its warmest 51 years during the current 2,000 years (Neukom, et al. 2019).

Recent research suggests that Phoenix's climate will resemble that of Baghdad by 2050 (Bastin, et al. 2019). During the summer, Baghdad typically receives no rainfall. Baghdad's average high temperatures (Weather Atlas 2002-2020) during the summer months are:

June: 105.8°

July: 111.2°

August: 109.4°

Summer Average High Temperature: 108.8°

Until summer 2020, the highest mean summer maximum temperature was 107.0°, which was set in 1978 and tied in 1989. The highest monthly summer maximum temperature was 109.8°, which was set in July 1989 and tied in July 2020. August 2020 surpassed that record with an average high temperature of 110.7°.

As recently as 2000, Phoenix's average low temperature during the summer was 79.8°. Since 1999, Phoenix has had no summer with an average low temperature below 80.0°. Prior to 2020, the highest average monthly minimum temperature was 87.5°, which was set in August 2011. July 2020 had an average minimum temperature of 88.0°.

Based on the above research findings, summer 2020 provides a glimpse of what a typical Phoenix summer will be like by 2050.

Table 6: Average Summer Temperatures (30-Year Moving Average)

Climate change is also resulting in an increase in the frequency of days on which the low temperature stays at or above 90° and the high temperature reaches 100° or above, 110° or above, and 115° or above.

Table 7: Average Annual Days at Set Thresholds (30-Year Moving Average)

According to the Fourth National Climate Assessment, Phoenix saw 60 to nearly 100 100° days per year at the 5th and 95th percentiles. Under the RCP 4.5 scenario, those figures are projected to increase to 110-141 days per year during the 2070-2099 period. During the 1950-1999 period, 9 (18%) of years saw the number of 100° days fall within the projected RCP 4.5 interval (U.S. Global Change Research Program, 2017). From 2000-2019, 11 (55%) of years fell within that interval. 2020 is all but certain to become the 12th case since 2000 to meet that higher interval. Moreover, through August 31, the 30-year moving average is just above 110 days per year.

During the summer, 48 days saw high temperatures 110° or above. The previous summer record was 31 days, which was set in 2007 and tied in 2011. During 2020, there have been 50 such days vs. the prior record of 33 days, which was set in 2011. There were also 28 days on which the minimum temperature was 90° or above, which eclipsed the previous record of 15, which was set in 2003 and tied in 2013.

In addition, the number of very hot (high temperature of 110° or above) and super hot (high temperature of 115° or above) days has been increasing as a share of the increasing number of 100° days. For the 30-year period ending in 1980, 12.6% of 100° days had high temperatures of 110° or above and 1.0% saw temperatures reach 115° or above. For the 30-year period ending in 2000, those figures increased to 15.7% and 1.7% respectively. For the period ending in 2020 (through August 31), those figures increased further to 18.7% and 2.0% respectively.

Overall, the frequency and intensity of compound summertime hot extremes (events that combine daytime and nighttime heat where such temperatures are above their 90th percentile for their calendar) has been increasing especially in geographic locations that include the U.S. Southwest (Wang 2020). The increase in forcing associated with anthropogenic greenhouse gases is the dominant driver of this outcome. (Wang 2020). During summer 2020, 15 record high minimum temperatures were tied or broken in Phoenix and 14 record high maximum temperatures were tied or broken. On 7 days, both record high minimum and maximum temperatures were tied or broken.

Summary:

Summer 2020 saw Phoenix record its highest summer temperature on record. It also saw Phoenix experience its two hottest months on record. In addition, Phoenix easily surpassed records for most days on which the temperature reached 110° or above and on which minimum temperature was 90° or higher.  

Anthropogenic climate change, which has turned hot patterns hotter and increased pattern persistence, is largely responsible for this exceptional warmth. Based on the latest research, the extreme heat of summer 2020 will likely become the "new normal" by 2050.

 

What will the extreme heat of 2050 be like? 140s? 110s for lows?

[donsutherland1]

8 minutes ago, Bhs1975 said:

What will the extreme heat of 2050 be like? 140s? 110s for lows?

If the idea that Phoenix’s climate will resemble that of Baghdad is reasonably accurate, then there could be some nights with lows at or above 100 (Phoenix’s lows are higher than those in Baghdad) and highs in the lower and middle 120s during periods of extreme heat. 

[donsutherland1]

From the NWS Phoenix forecast office:

 

 

[Great Snow 1717]

Don't worry JB will explain it all away.........

[madwx]

In addition, Chicago, Tampa, Miami, Harrisburg and a few dozen other cities have also had their warmest summer on record

[donsutherland1]

Another tweet from the Phoenix office of the National Weather Service:

https://twitter.com/NWSPhoenix/status/1300795549499756544?s=20

[blizzard1024]

It is the development, UHI that is leading to warmer conditions in Phoenix. Come on. Its not "climate change". Globally this summer had anomalies ranging from .43 to .44C worldwide which is pretty small. Yes this is using the UAH satellite temperature record which is the most accurate by far. RSS artificially inflated their temperatures around 2015 to get in line with the flawed and adjusted (upward) surface records. The Earth has warmed since the late 1970s, a known cool period in the 20th century when the satellite record began. We are back to where we were in the 1930s, 40s and 50s globally. Before that we have no idea since temperatures were taken differently with respect to time, and instrumentation. Also SSTs back then were terrible.  Let's hype everything up. That is what the world does these days!  

[blizzard1024]

Here are Phoenix's yearly average low temperatures...

 

Here is the population growth.... 

Here are the average highs and you can see a slower growth which makes sense. More people equals more grass, lawn watering and more water vapor. 

 

 

This is NOT climate change. Pretty obvious. let's get back to science and stop with the hype and propaganda. 

[madwx]

Come on guys.  It’s not man made climate change, it’s just man made changes to the environment that are making things warmer 

[donsutherland1]

4 hours ago, blizzard1024 said:

Here are Phoenix's yearly average low temperatures...

 

Here is the population growth.... 

Here are the average highs and you can see a slower growth which makes sense. More people equals more grass, lawn watering and more water vapor. 

 

 

This is NOT climate change. Pretty obvious. let's get back to science and stop with the hype and propaganda. 

Urbanization was cited as one of three factors by the National Weather Service. Climate change was another.

Moreover, the idea that urbanization is responsible for the outcome was addressed by NWS Phoenix which stated, "The record summer heat wasn't just in Phoenix, or solely due to Urbanization. A large chunk of the SW saw exceptional heat and all-time records. Some other locations w/ all-time summer records: Lost Dutchman SP, Carefree, Tombstone, Tucson, & Nogales."

[blizzard1024]

3 minutes ago, donsutherland1 said:

Urbanization was cited as one of three factors by the National Weather Service. Climate change was another.

Moreover, the idea that urbanization is responsible for the outcome was addressed by NWS Phoenix which stated, " he record summer heat wasn't just in Phoenix, or solely due to Urbanization. A large chunk of the SW saw exceptional heat and all-time records. Some other locations w/ all-time summer records: Lost Dutchman SP, Carefree, Tombstone, Tucson, & Nogales."

All these places have been settled recently which leads to warmer temperatures. UHI is not only in big cities. There has been a mass migration to the SW US the last few decades and this itself is causing temperature rises. So a normally warm summer pattern becomes record breaking because of UHI. You can't blame in on CO2.  

[blizzard1024]

Looks at Nogales, AZ which has a Mexican counterpart....again a large increase in population. This NO doubt contributes to the UHI. The minimum temperatures come up more than the maximums. 

 

[blizzard1024]

In the desert climates, the influence of UHI is larger since there are fewer clouds with stronger direct insolation. Pavement makes a big difference. Plus adding lawns, and vegetation leads to more water vapor which holds more heat in. There is no doubt the SW US temperature records are seriously affected by the recent rapid population changes. The surface records are seriously contaminated. 

[bdgwx]

2 hours ago, blizzard1024 said:

RSS artificially inflated their temperatures around 2015

Hmm...I'm not sure what you mean by "artificially inflate". Here is RSS's paper describing their changes in v4.

https://journals.ametsoc.org/jcli/article/30/19/7695/342699/A-Satellite-Derived-Lower-Tropospheric-Atmospheric

RSS matches other observational sources including but not limited to.

STAR: https://www.ncdc.noaa.gov/temp-and-precip/msu/global/mt/dec/ytd

RATPAC: https://www.ncdc.noaa.gov/sotc/upper-air/201913

ERA: https://climate.copernicus.eu/sites/default/files/2020-08/ts_1month_anomaly_Global_ERA5_2T_202007_v01.csv

Berkeley Earth: http://berkeleyearth.lbl.gov/auto/Global/Land_and_Ocean_complete.txt

GISTEMP: https://data.giss.nasa.gov/gistemp/graphs_v4/graph_data/Monthly_Mean_Global_Surface_Temperature/graph.txt

Cowtan & Way: https://www-users.york.ac.uk/~kdc3/papers/coverage2013/series.html

JMA: https://ds.data.jma.go.jp/tcc/tcc/products/gwp/temp/ann_wld.html

HadCRUT: https://crudata.uea.ac.uk/cru/data/temperature/

NOAA Global Temp: https://www.ncei.noaa.gov/data/noaa-global-surface-temperature/v5/access/timeseries/aravg.ann.land_ocean.90S.90N.v5.0.0.202007.asc

2 hours ago, blizzard1024 said:

to get in line with the flawed and adjusted (upward) surface records.

All datasets are adjusted. That is a good thing. We want dataset developers and maintainers to make adjustments to correct for mistakes, biases, data quality issues, non-climatic effects, etc. That does not mean these datasets are fundamentally flawed. adjusted != flawed and adjusted == good

And remember UAH makes all kinds of adjustments too. They don't even directly measure the temperature. They have to derive it using a complex model that maps microwave emissions from O2 molecules into a meaningful temperature. And they have to make adjustments to correct for things like orbital decay, diurnal drift, and instrument body effect.  Then they have to homogenize the data to provide global coverage while dealing with subtle nuances in the polar regions.

No source code is provided by UAH. Not that I think this is a problem. Many datasets decline to publish the details of their techniques. However many datasets like GISTEMP openly publish their source code for all to review. 

2 hours ago, blizzard1024 said:

Yes this is using the UAH satellite temperature record which is the most accurate by far.

Out of the more than a dozen datasets in existence that publish a global mean temperature UAH is the outlier; perhaps even a lone outlier compared against the backdrop of the more well known GMST datasets. 

Many are suspicious that the UAH TLT product is being contaminated by the cooling stratosphere. RSS TLT != UAH TLT. RSS weights their TLT product much lower than UAH's TLT product. And from their TMT products it is RSS that has a better match to balloon observations.

https://www.ncdc.noaa.gov/sotc/upper-air/201913

There are also data merging issues.

https://journals.ametsoc.org/jtech/article/34/1/225/342433/A-Comparative-Analysis-of-Data-Derived-from

2 hours ago, blizzard1024 said:

The Earth has warmed since the late 1970s, a known cool period in the 20th century when the satellite record began. We are back to where we were in the 1930s, 40s and 50s globally.

Please review the published data linked to above concerning the global mean temperature.

3 hours ago, blizzard1024 said:

Before that we have no idea since temperatures were taken differently with respect to time, and instrumentation.

Scientists do have an idea. The uncertainty envelope is definitely wider in the past. But it is not infinitely wide. For example Berkeley Earth lists less than 0.10C for the annual mean error from 1880 onward. This is reduced to less than 0.07C error if using the 5 year centered running mean.  Annual mean errors drop to 0.05C after 1960.

3 hours ago, blizzard1024 said:

This is NOT climate change. Pretty obvious. let's get back to science and stop with the hype and propaganda. 

The science says climate change IS a component. Even with non-climatic changes controlled for the Phoenix area trend is clearly upwards. It's hard to say how much of Phoenix's warming is due to the broad increase in the global mean temperature or more cyclic climate phenomenon like the PDO, AMO, etc. But we know from first principal reasoning that climate change HAS to be factor because temperature trends are a product of ALL modulating effects.

https://data.giss.nasa.gov/cgi-bin/gistemp/stdata_show_v4.cgi?id=USW00093140&ds=14&dt=1

https://data.giss.nasa.gov/cgi-bin/gistemp/stdata_show_v4.cgi?id=USW00023183&ds=14&dt=1

 

 

[blizzard1024]

Scientists know what the ocean temperatures were 100 to 150 years ago before large scale buoys and especially since before the satellite era. I call BS. Come on. Its conjecture that far back. Plus the Little Ice Age ended in the 1800s. A natural warming trend could be occurring anyway. You must involve climate models to "prove" CO2 increases are the primary component of global warming. That is NOT science. Its models. I have been working with atmospheric models for 30+ years and they are a crude representation of the atmosphere.  It boils down to computer models getting non-linear chaotic feedbacks correct. This is extremely problematic. If you believe the feedbacks from these models, you believe in significant global warming. That is a leap of faith. CO2 never controlled the climate during the last several glaciations as it passively follows the temperature records. So why all of the sudden does it control the climate now? Plus if we had a very sensitive climate system dominated by positive feedbacks, any shock to the system in the past would have shifted the climate either to extreme warm or an ice earth. That has not happened. CO2 is a minor GHG with a small absorption band centered around 15 microns. water vapor and clouds are the primary and dominate GHGs. Ocean currents as well are really important aspects of climate. CO2 not so much. sorry. that is what the science really says. The climate "scientists" or activists have ruined this branch of science by being political. 

I will add that these activists are a danger to the planet. By abandoning fossil fuels, the world goes into a deep depression, poverty becomes even more rampant. With poverty comes environmental destruction because people get desperate. Look at Haiti.  Solar panels and wind farms everywhere are destroying natural habitats. This "save the planet" hype is ruining natural habitats and is a threat to the environment. A small warming of 1-2C  will not wreck the Earth if it even occurs.  The insanity. 

[donsutherland1]

41 minutes ago, blizzard1024 said:

In the desert climates, the influence of UHI is larger since there are fewer clouds with stronger direct insolation. Pavement makes a big difference. Plus adding lawns, and vegetation leads to more water vapor which holds more heat in. There is no doubt the SW US temperature records are seriously affected by the recent rapid population changes. The surface records are seriously contaminated. 

Initially, one could make a compelling argument that Phoenix’s warming was being driven by growing urbanization. But that has changed.

During the 1990-2020 period, the 30-year moving average for summer temperatures rose 2.7° at Phoenix but 1.4° at Tombstone (current population 1,330). However, if one excludes the 1990s, the increases were 1.5° and 1.0° respectively. Since 2010, Tombstone actually saw greater warming than Phoenix, even as its population fell slightly from 1,382.

In addition, as with Phoenix, a disproportionate share of Tombstone’s 10 warmest summers have occurred since 2000. In fact, 9 of Tombstone’s 10 warmest summers have occurred since 2010.

In sum, the recent data is consistent with what the overwhelming body of scientific research shows overall: Most of the recent warming is related to anthropogenic climate change, not location-specific factors such as the Urban Heat Island (UHI) effect. Not surprisingly, IPCC is considering raising the level of confidence about the role of anthropogenic factors leading to most of the recent warming to 99%-100% for the Sixth Assessment Report that will be published next year.

 

[blizzard1024]

3 minutes ago, donsutherland1 said:

Initially, one could make a compelling argument that Phoenix’s warming was being driven by growing urbanization. But that has changed.

During the 1990-2020 period, the 30-year moving average for summer temperatures rose 2.7° at Phoenix but 1.4° at Tombstone (current population 1,330). However, if one excludes the 1990s, the increases were 1.5° and 1.0° respectively. Since 2010, Tombstone actually saw greater warming than Phoenix, even as its population fell slightly from 1,382.

In addition, as with Phoenix, a disproportionate share of Tombstone’s 10 warmest summers have occurred since 2000. In fact, 9 of Tombstone’s 10 warmest summers have occurred since 2010.

In sum, the recent data is consistent with what the overwhelming body of scientific research shows overall: Most of the recent warming is related to anthropogenic climate change, not location-specific factors such as the Urban Heat Island (UHI) effect. Not surprisingly, IPCC is considering raising the level of confidence about the role of anthropogenic factors leading to most of the recent warming to 99%-100% for the Sixth Assessment Report that will be published next year.

 

 

How can you say this? How do you know it is not natural warming?  CO2 is a minor GHG. The IPCC is a political organization with an agenda. You can't call that real unbiased science. That's my scientific opinion. I will respect yours. I am sorry if I come off strong. It seems that you have to on these forums or you get compared to holocaust deniers which really is a massive insult to me on a personal level. 

 

[forkyfork]

your opinion is worthless

[donsutherland1]

14 minutes ago, blizzard1024 said:

 

How can you say this? How do you know it is not natural warming?  CO2 is a minor GHG. The IPCC is a political organization with an agenda. You can't call that real unbiased science. That's my scientific opinion. I will respect yours. I am sorry if I come off strong. It seems that you have to on these forums or you get compared to holocaust deniers which really is a massive insult to me on a personal level. 

 

I have confidence in the large and growing body of peer-reviewed research on the matter. Further, there is no alternative explanation that even begins to account for the observed warming that has occurred since 1950. Models that rely solely on natural forcings cannot reliably reproduce the warming. Those that include anthropogenic greenhouse gases do very well. 

[blizzard1024]

2 minutes ago, forkyfork said:

your opinion is worthless

How so?  I have been studying this topic for 30 years and have an MS in atmospheric science. I have conversed with top minds in radiative transfer and the whole CO2 leading to catastrophic dangerous warming is just not accurate. It doesn't fit with the paleo records. It does fit with the radiative transfer. it doesn't make sense with the feedbacks...I can go on.... What is your scientific opinion? 

[blizzard1024]

2 minutes ago, donsutherland1 said:

I have confidence in the large and growing body of peer-reviewed research on the matter. Further, there is no alternative explanation that even begins to account for the observed warming that has occurred since 1950. Models that rely solely on natural forcings cannot reliably reproduce the warming. Those that include anthropogenic greenhouse gases do very well. 

Again MODELs.  Models assume the climate was in stasis in 1850. That is a bad assumption since the LIA was ending. Models don't even accurately depict convection or clouds which are MAJOR players in the global energy budget. it is a leap of faith. And cut it with this peer reviewed high horse stuff. If it challenges the viewpoint that CO2 levels are dangerous, it doesn't get published. Peer review paper quality has gone WAY down of late. I review papers in atmospheric science, not climate thankfully, and the quality has gone way down since the 1990s. I can't believe the crap that makes it through these days.... 

[BillT]

4 minutes ago, blizzard1024 said:

How so?  I have been studying this topic for 30 years and have an MS in atmospheric science. I have conversed with top minds in radiative transfer and the whole CO2 leading to catastrophic dangerous warming is just not accurate. It doesn't fit with the paleo records. It does fit with the radiative transfer. it doesn't make sense with the feedbacks...I can go on.... What is your scientific opinion? 

i admire your efforts here and you are correct, earlier you noted the 1930s warmth which clearly was erased by the creator of the charts that started this thread........in that way of thinking indeed this whole story is man made, man manipulating the statistics to create a false image........simple common sense is IF co2 was indeed trapping heat and blocking a portion of the IR waves taking heat from the earth to space, each and every day the total heat here would increase and the earth would have been a cinder long ago

[blizzard1024]

5 minutes ago, BillT said:

i admire your efforts here and you are correct, earlier you noted the 1930s warmth which clearly was erased by the creator of the charts that started this thread........in that way of thinking indeed this whole story is man made, man manipulating the statistics to create a false image........simple common sense is IF co2 was indeed trapping heat and blocking a portion of the IR waves taking heat from the earth to space, each and every day the total heat here would increase and the earth would have been a cinder long ago

BillT, 

CO2 doesn't "trap" heat per se, it absorbs and emits IR radiation (or heat I suppose) at the 15 micron wavelength primarily which according to Wein's Law is most active at -50C to -80C or so. Water vapor and clouds have a much broader IR absorption spectrum and are the primary GHGs. All these GHGs DO indeed warm up the Earth. But they also cool the layers above because radiation is emitted in all directions. So cooling occurs above the warming directed down to the surface. If we didn't have convection, radiatively the Earths temperature would be a scorching 160F on average.   But we do. Convection i.e thunderstorms redistribute heat to the upper troposphere and out to space. So with convection the greenhouse effect is reduced to about 33K above the Earths blackbody temperature of 255K. The weather lead to earth's temperature stabilizing and ultimately the sun is the control knob for our weather.  

[donsutherland1]

25 minutes ago, BillT said:

i admire your efforts here and you are correct, earlier you noted the 1930s warmth which clearly was erased by the creator of the charts that started this thread........in that way of thinking indeed this whole story is man made, man manipulating the statistics to create a false image........simple common sense is IF co2 was indeed trapping heat and blocking a portion of the IR waves taking heat from the earth to space, each and every day the total heat here would increase and the earth would have been a cinder long ago

Here is the extended information that includes the 30-year periods ending in 1930 and 1940 for Phoenix.

Average Summer Temperatures (30-Year Moving Average):

[BillT]

ty for the response somewhere around here i posted in laymans terms what you wrote, that an IR wave leaves the earth and a small portion of it excites a co2 molecule which in turn releases a new IR wave with no directional push......the "heat" is what happens when the energy of the IR and other lengths of waves interact with molecules.

[donsutherland1]

Article on Phoenix’s historic summer by The Washington Post’s Capital Weather Gang:

https://www.washingtonpost.com/weather/2020/09/01/phoenix-hottest-summer

[bdgwx]

10 hours ago, blizzard1024 said:

Scientists know what the ocean temperatures were 100 to 150 years ago before large scale buoys and especially since before the satellite era. I call BS. Come on. Its conjecture that far back.

Let's be precise. The 2σ error on a 5yr centered mean 150 years ago is about 0.100C. 100 years ago it is about 0.085C. 60 years ago it is about 0.035C. Obviously everyone agrees that 0.1C error is larger than 0.035C of error. But I don't think many people are going to consider these measurements to be BS because of it. Source. 

10 hours ago, blizzard1024 said:

Plus the Little Ice Age ended in the 1800s. A natural warming trend could be occurring anyway.

Then it should have been easy to identify.

Of course, you'd still have the problem of figuring out where all of that accumulated (aka "trapped") energy that GHGs yielded went if not into warming the atmosphere and hydrosphere. This is tough nut to crack for sure. 

10 hours ago, blizzard1024 said:

You must involve climate models to "prove" CO2 increases are the primary component of global warming.

Yes and no. First...that's no different than using Kepler's model of planetary motion or Einsteins model of general relatively to "prove" that the Sun is the primary component of Earth's movement in the solar system for example. I mean science constructs models specifically to address to question like these. It's ubiquitous across all disciplines of science so I don't see what the problem is here. Second...there are many observational lines of evidence that corroborate CO2's role while simultaneously eliminating other candidates (like the cooling stratosphere simultaneous with the warming troposphere and hydrosphere). And the various models like radiative transfer schems, energy balance, and GCMs are developed from observational evidence themselves. So if the implication is that "model" means "no observations" then that's not giving the state of the science a fair shake. 

10 hours ago, blizzard1024 said:

That is NOT science. Its models.

Science constructs models that approximate reality. That's kind of the point of science actually. And when more than one model exists scientists, engineers, or other decision makers typically choose the one that provides the best match to reality with no more complexity than is absolutely necessary for the task.

10 hours ago, blizzard1024 said:

I have been working with atmospheric models for 30+ years and they are a crude representation of the atmosphere.  It boils down to computer models getting non-linear chaotic feedbacks correct. This is extremely problematic.

Ah...when you say model you actually mean "global circulation model". Not all climate models are GCMs, but GCMs are a type of climate model. The most primitive climate model came in the late 1800's (see Arrhenius 1896). Models got more sophisticated and by the 1950's were using radiative transfer schemes (see Plass 1956). By the 70's climate models achieved a level of sophistication requiring numerical weather prediction techniques via global circulation models. By the 1980's these GCMs were incorporating many GHG species, solar effects, aerosol effects, etc. (see Hansen 1988). Radiative transfer schemes themselves were improving as well (see Myhre 1998). We also have energy balance models (see Wild 2013). More to the point...in the GCM arena even the primitive ones from 30 years ago ended up performing reasonably well (see Hausfather 2020). So while they may be considered crude they still work well and are orders of magnitude more complex than their non-GCM counterparts appearing between 60-120 years ago. All models have problems. That's why they are only approximations of reality. 

10 hours ago, blizzard1024 said:

This is extremely problematic. If you believe the feedbacks from these models, you believe in significant global warming.

It's a good thing scientists do not base their conclusions on future warming from GCMs alone.

10 hours ago, blizzard1024 said:

CO2 never controlled the climate during the last several glaciations as it passively follows the temperature records.

As expected. CO2 is both in a forcing AND a feedback relationship with the temperature. When something else catalyzes the temperature change CO2 acts via its feedback first and then as a forcing agent second to amplify the temperature change. When CO2 itself catalyzes the temperature change it acts as a forcing agent first and then via its feedback it will amplify the change through the perturbation of existing source/sink fluxes. It would be rather odd if we had discovered that CO2 lead the temperature changes during the glacial cycles.

But there are other events in the paleoclimate record in which CO2 did lead the temperature. These include the hyperthermal events. The most notable of which and the one that is most analogous to the contemporary warning is the PETM. There was a sudden and dramatic release of carbon (possibly CH4 or CO2 or both) that preceded the hyperthermal just like the other ETMx events.

10 hours ago, blizzard1024 said:

So why all of the sudden does it control the climate now?

Because it is a radiative forcing agent and because it is being released during an era in which other modulating factors have remained relatively unchanged or may have actually caused a cooling tendency.

10 hours ago, blizzard1024 said:

Plus if we had a very sensitive climate system dominated by positive feedbacks, any shock to the system in the past would have shifted the climate either to extreme warm or an ice earth. That has not happened.

It has happened. Many times in fact. I would consider the glacial cycles of the Quaternary Period a flip from one extreme to another. But of course their have been snowball Earth and hothouse Earth conditions as well.

10 hours ago, blizzard1024 said:

CO2 is a minor GHG with a small absorption band centered around 15 microns. water vapor and clouds are the primary and dominate GHGs.

But remember...H2O is a condensing gas. CO2 is non-condensing. H2O produces a radiative forcing but due to its condensing nature it is not considered a forcing agent since it cannot, on its own, catalyze a long term change in temperature. It is happy to remain in its stable equilibrium with the temperature via the Clausius-Clapeyron relationship all other things remaining equal. In other words, H2O can amplify an already catalyzed change, but it cannot actually catalyze that change on its own.

10 hours ago, blizzard1024 said:

Ocean currents as well are really important aspects of climate. CO2 not so much. sorry. that is what the science really says.

Ocean currents are important. But not in terms in of Earth's Energy Imbalance (EEI). Ocean currents do not create energy or directly change EEI. Their contribution to the EEI is thus 0 W/m^2. CO2's contribution from 280 to 410 ppm is +2.0 W/m^2. That makes CO2 vastly more important to Earth's secular climate trends than ocean currents which only have a cyclic effect through their ebb and flow of heat transfer fluxes to/from the atmosphere and deep ocean and how this heat is distribution over the Earth.

9 hours ago, blizzard1024 said:

CO2 doesn't "trap" heat per se

Yes it does. Quite literally in fact. In the context in which it is used in climate science the word "trap" means energy (and by extension heat) is accumulating via a planetary scale energy imbalance. This imbalance is currently +0.6 W/m^2. Therefore 0.6 W/m^2 is being "trapped" in the geosphere. CO2's un-equilibriated radiative force is a significant contributor to this "trapped" energy.

9 hours ago, blizzard1024 said:

The weather lead to earth's temperature stabilizing and ultimately the sun is the control knob for our weather.  

The Sun is not THE control knob, but only A control knob. There are other factors that modulate the climate. It is the net effect of all of them matters. Sometimes the Sun does dominate. Sometimes volcanoes dominate. Sometimes orbital cycles provide the nudge to hit the tipping point. We just happen to be living in an era when GHGs are dominating.

BTW...it's really easy to falsify the "It's the Sun stupid" hypothesis. First...like all main sequence stars the Sun brightens and warms with age. The rate is about 1% every 120 million years see (Gough 1981). The paleoclimate record shows secular cooling over million year time scales despite solar luminosity increasing. If the Sun where THE control knob then we should have expected the Earth to warm. But that didn't happen. This is the crux of the faint young paradox. Why was Earth so warm in the distant past when the Sun was significantly less bright?  Second...over the contemporary warming period and especially since 1960 solar radiation has been mostly flat and has even started to decline in the most recent decades. Yet the warming rate didn't turn negative. In fact, the warming actually accelerated during this period and in complete opposition to total solar irradiance (see SORCE). This leaves only solar magnetic flux as a candidate for influence. But as I've pointed in other posts there are far too many problems with the galactic cosmic ray hypothesis to consider it a viable hypothesis at this point. I can provide references if necessary.

 

 

[blizzard1024]

IR active gases do not TRAP radiation. That is flawed science. My radiative transfer professor would got nuts when people said that. It absorbs and re-emits radiation in all directions. That is not TRAPPING.

[blizzard1024]

4 minutes ago, bdgwx said:

Let's be precise. The 2σ error on a 5yr centered mean 150 years ago is about 0.100C. 100 years ago it is about 0.085C. 60 years ago it is about 0.035C. Obviously everyone agrees that 0.1C error is larger than 0.035C of error. But I don't think many people are going to consider these measurements to be BS because of it. Source. 

Then it should have been easy to identify.

Of course, you'd still have the problem of figuring out where all of that accumulated (aka "trapped") energy that GHGs yielded went if not into warming the atmosphere and hydrosphere. This is tough nut to crack for sure. 

Yes and no. First...that's no different than using Kepler's model of planetary motion or Einsteins model of general relatively to "prove" that the Sun is the primary component of Earth's movement in the solar system for example. I mean science constructs models specifically to address to question like these. It's ubiquitous across all disciplines of science so I don't see what the problem is here. Second...there are many observational lines of evidence that corroborate CO2's role while simultaneously eliminating other candidates (like the cooling stratosphere simultaneous with the warming troposphere and hydrosphere). And the various models like radiative transfer schems, energy balance, and GCMs are developed from observational evidence themselves. So if the implication is that "model" means "no observations" then that's not giving the state of the science a fair shake. 

Science constructs models that approximate reality. That's kind of the point of science actually. And when more than one model exists scientists, engineers, or other decision makers typically choose the one that provides the best match to reality with no more complexity than is absolutely necessary for the task.

Ah...when you say model you actually mean "global circulation model". Not all climate models are GCMs, but GCMs are a type of climate model. The most primitive climate model came in the late 1800's (see Arrhenius 1896). Models got more sophisticated and by the 1950's were using radiative transfer schemes (see Plass 1956). By the 70's climate models achieved a level of sophistication requiring numerical weather prediction techniques via global circulation models. By the 1980's these GCMs were incorporating many GHG species, solar effects, aerosol effects, etc. (see Hansen 1988). Radiative transfer schemes themselves were improving as well (see Myhre 1998). We also have energy balance models (see Wild 2013). More to the point...in the GCM arena even the primitive ones from 30 years ago ended up performing reasonably well (see Hausfather 2020). So while they may be considered crude they still work well and are orders of magnitude more complex than their non-GCM counterparts appearing between 60-120 years ago. All models have problems. That's why they are only approximations of reality. 

It's a good thing scientists do not base their conclusions on future warming from GCMs alone.

As expected. CO2 is both in a forcing AND a feedback relationship with the temperature. When something else catalyzes the temperature change CO2 acts via its feedback first and then as a forcing agent second to amplify the temperature change. When CO2 itself catalyzes the temperature change it acts as a forcing agent first and then via its feedback it will amplify the change through the perturbation of existing source/sink fluxes. It would be rather odd if we had discovered that CO2 lead the temperature changes during the glacial cycles.

But there are other events in the paleoclimate record in which CO2 did lead the temperature. These include the hyperthermal events. The most notable of which and the one that is most analogous to the contemporary warning is the PETM. There was a sudden and dramatic release of carbon (possibly CH4 or CO2 or both) that preceded the hyperthermal just like the other ETMx events.

Because it is a radiative forcing agent and because it is being released during an era in which other modulating factors have remained relatively unchanged or may have actually caused a cooling tendency.

It has happened. Many times in fact. I would consider the glacial cycles of the Quaternary Period a flip from one extreme to another. But of course their have been snowball Earth and hothouse Earth conditions as well.

But remember...H2O is a condensing gas. CO2 is non-condensing. H2O produces a radiative forcing but due to its condensing nature it is not considered a forcing agent since it cannot, on its own, catalyze a long term change in temperature. It is happy to remain in its stable equilibrium with the temperature via the Clausius-Clapeyron relationship all other things remaining equal. In other words, H2O can amplify an already catalyzed change, but it cannot actually catalyze that change on its own.

Ocean currents are important. But not in terms in of Earth's Energy Imbalance (EEI). Ocean currents do not create energy or directly change EEI. Their contribution to the EEI is thus 0 W/m^2. CO2's contribution from 280 to 410 ppm is +2.0 W/m^2. That makes CO2 vastly more important to Earth's secular climate trends than ocean currents which only have a cyclic effect through their ebb and flow of heat transfer fluxes to/from the atmosphere and deep ocean and how this heat is distribution over the Earth.

Yes it does. Quite literally in fact. In the context in which it is used in climate science the word "trap" means energy (and by extension heat) is accumulating via a planetary scale energy imbalance. This imbalance is currently +0.6 W/m^2. Therefore 0.6 W/m^2 is being "trapped" in the geosphere. CO2's un-equilibriated radiative force is a significant contributor to this "trapped" energy.

The Sun not THE control know, but only A control knob. There are other factors that modulate the climate. It is the net effect of all of them matters. Sometimes the Sun does dominate. Sometimes volcanoes dominate. Sometimes orbital cycles provide the nudge to hit the tipping point. We just happen to be living in an era with GHGs are dominating.

BTW...it's really easy to falsify the "It's the Sun stupid" hypothesis. First...like all main sequence stars the Sun brightens and warms with age. The rate is about 1% every 120 million years see (Gough 1981). The paleoclimate record shows secular cooling over million year time scales despite solar luminosity increasing. If the Sun where THE control knob then we should have expected the Earth to warm. But that didn't happen. This is the crux of the faint young paradox. Why was Earth so warm in the distant past when the Sun was significantly less bright?  Second...over the contemporary warming period and especially since 1960 solar radiation has been mostly flat and has even started to decline in the most recent decades. Yet the warming rate didn't turn negative. In fact, the warming actually accelerated during this period and in complete opposition to total solar irradiance (see SORCE). This leaves only solar magnetic flux as a candidate for influence. But as I've pointed in other posts there are far too many problems with the galactic cosmic ray hypothesis to consider it a viable hypothesis at this point. I can provide references if necessary.

 

 

The oceans are a store house for energy and damp any forcings. So a quieter sun would take a while to get into the climate system.