donsutherland1

That’s much lower than both the mean point and the minimum figure in the consensus ECS estimates.

Every scientific field relies on models to represent complex phenomena. Climate science is no exception. The expectation that models should outright be ignored is unreasonable and impractical. They physics associated with CO2 is well-established. Even absent modeling, one should reasonably expect that increased atmospheric concentration of CO2 (not to mention other greenhouse gases) would lead to an increase in temperatures, among other things. One would need to reject physics to expect a different outcome. That’s a far riskier course. That the expected observed warming has been underway is consistent with expectations. The modeling brings a much greater insight into what is happening.

If it were natural, it would be replicated with just the natural forcing. Instead, around the middle of the 20th century one finds a divergence between temperatures and the natural forcings. Only the introduction of greenhouse gases explains the temperature trend and addresses the divergence.

Those are sweeping generalizations. They are not based on data or other forms of evidence. They are premised on the idea that an outlier dataset is accurate while every other dataset is not, without any evidence to support such an extraordinary claim. In general, if one seeks to make a case, one must have evidence to support that case. Absent supporting evidence, one needs sufficient evidence to reject a position that one argues is flawed. Neither condition is satisfied above. First, the earth has had a persistent, long-running positive energy imbalance. That imbalance has persisted regardless of changes in solar irradiance, a development that demonstrates the dominant impact greenhouse gases are having in driving that imbalance (Hansen et al., 2011 and Schuckmann et al., 2020). Such imbalances lead to heating until a new equilibrium is established. The overwhelming share (89%) of the heat from the observed energy imbalance has gone into the oceans (Schuckmann et al., 2020). In addition, 4% has gone into heating the land. All major datasets—Berkeley, GISS, HadCru, and NOAA—demonstrate sustained warming is underway with the last decade the warmest, so far, during the instrument record. Paleoclimate reconstructions show that the current warming is anomalous during the Holocene. Flora and fauna have been responding in a fashion consistent with warming. The warming is no artifact of human data manipulation. Otherwise, there would be no changes in bird migrations, blooming, a shift in growing zones, etc. 3% of the heating has gone to melting ice. Greenland and Antarctica have been losing mass, resulting in sea level rise. Arctic sea ice minimum extent has been growing lower, with 2019 and 2020 the first cases during which the minimum extent was below 4 million square kilometers in consecutive years. Second, all the known natural forcings have been assessed. The natural forcings, by themselves, cannot explain the observed warming that has taken place since the middle and especially latter part of the 20th century. Only approaches that include greenhouse gases can explain the observed warming (Foster and Ramstorf, 2011 and Jones et al., 2013). Third, UAH has been found to have a cool bias on account of the adjustments that are made in preparing that dataset (Po-Chedley et al., 2015). No evidence has been furnished to suggest that this dataset is superior, much less that it is superior to all the others despite the biases introduced by the adjustments involved. In sum, no evidence has been provided to undermine the credibility of the AGW explanation. Claims of adjustments (as if preferred datasets such as UAH don’t involve adjustments), attacks on peer review for the absence of papers advancing a credible alternative to AGW, and unsubstantiated claims of a ‘CO2 tail wagging the climate research dog’ do not make a contribution to understanding ongoing climate change, much less undercut the AGW explanation. They do provide an exhibit for the lack of credible alternative explanation. Referenced Papers: Hansen et al., 2011: https://pubs.giss.nasa.gov/docs/2011/2011_Hansen_ha06510a.pdf Schuckmann, et al., 2020: https://essd.copernicus.org/articles/12/2013/2020 Foster and Ramstorf, 2011: https://iopscience.iop.org/article/10.1088/1748-9326/6/4/044022 Jones et al., 2013: https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1002/jgrd.50239 Po-Chedley et al., 2015: https://journals.ametsoc.org/jcli/article/28/6/2274/35327/Removing-Diurnal-Cycle-Contamination-in-Satellite

Scientists have acknowledged where uncertainties exist. While there are differences in water vapor measurements and both dry and wet biases depending on which measures are used, not to mention a noted lack of understanding concerning water vapor transport and dehydration, the consensus is that atmospheric water vapor has been increasing. For example, below are excerpts from a World Meteorological Organization bulletin: Trends in observed atmospheric water vapour are hampered by inhomogeneities in data records, which occur when measurement programmes are discontinued because of, for example, the limited lifespans of satellite missions or insufficiently documented or understood changes in instrumentation. Combining records from different instruments that do not agree with one another is also a problem. One example is the offset between records from the HALOE and MLS satellite instruments. Nevertheless, observations show a steady increase of the total water vapour column as well as a 30-year net increase in stratospheric water vapour... These large discrepancies between different types of observational data, and between observations and reanalysis results, demonstrate significant uncertainties in the measurements as well as our lack of understanding of the transport and dehydration processes in the UTLS region. https://public.wmo.int/en/resources/bulletin/observing-water-vapour In sum, water vapor uncertainties and limited understanding tied to key water vapor processes do not provide a sound basis for rejecting the scientific consensus concerning AGW for which the overall body of evidence is overwhelming. Even with uncertainties, water vapor observations seem to lend additional support to AGW.

Morning thoughts... The coldest air so far this season remains in place. Today will be partly sunny and still very cool for the season. The temperature will likely top out in the lower and middle 60s across the region. Likely high temperatures around the region include: New York City (Central Park): 64° Newark: 65° Philadelphia: 66° Toward the middle of this week, a warmer pattern will develop. In terms of verification, here's how last evening's estimates worked out: Albany: 35°; Actual: 34° Allentown: 39°; Actual: 36° Boston: 46°; Actual: 44° Bridgeport: 47°; Actual: 49° Harrisburg: 42°; Actual: 43° Hartford: 38°; Actual: 36° Islip: 48°; Actual: 48° New York City: 48°; Actual: 50° Newark: 47°; Actual: 48° Philadelphia: 47°; Actual: 47° Poughkeepsie: 37°; Actual: 36° Providence: 44°; Actual: 46° White Plains: 42°; Actual: 45° Average Error: 1.5°

Temperatures reached only the lower and middle 60s across the region today despite bright sunshine. Tomorrow morning, Central Park will likely have a minimum temperature below 50°. The last time the temperature fell into the 40s in New York City during September was September 24, 2013 when the temperature fell to 47°. Select low temperature estimates include: Albany: 35° Allentown: 39° Boston: 46° Bridgeport: 47° Harrisburg: 42° Hartford: 38° Islip: 48° New York City: 48° Newark: 47° Philadelphia: 47° Poughkeepsie: 37° Providence: 44° White Plains: 42° Generally below normal readings could persist until near the middle of next week. Afterward, temperatures will moderate with temperatures returning to above normal levels for much of the remainder of the month. Today, Denver hit 90°. That was the 74th time this year that the temperature reached or exceeded 90° at Denver. The prior record was 73 days, which was set in 2012. The 30-year moving average of 90° days has also been increasing. Since 2000, Denver has added an average of 9.5 such days to its annual figure. Since 1950, the annual average has increased by just over 90% to an average of 44.6 days. The ENSO Region 1+2 anomaly was -1.0°C and the Region 3.4 anomaly was -1.0°C for the week centered around September 9. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -1.08°C and the ENSO Region 3.4 anomaly has averaged -0.75°C. La Niña conditions have developed and will likely prevail through the remainder of autumn. The SOI was +10.28. Today, the preliminary Arctic Oscillation (AO) figure was +1.003. On September 18, the MJO was in Phase 4 at an amplitude of 1.290 (RMM). The September 17-adjusted amplitude was 1.587. Since 1990, there have been 11 La Niña events, 6 of which followed an El Niño winter. 10/11 (91%) case saw warmer than normal September. All 6 following an El Niño winter were warmer than normal. September mean temperatures for New York City for those cases were: 11 cases: 69.9°; Subset of 6 cases: 70.8°; Entire 1990-2019 period: 69.0°. The September mean temperature for all La Niña and neutral-cool cases following an El Niño winter (1950-2019: n=13) was 69.9°. Since 1950, there have been five cases where a La Niña developed during June-July-August or afterward following an El Niño winter. 4/5 (80%) of those cases saw a predominant EPO+/AO+ winter pattern. The most recent such case was 2016-17. 9/10 (90%) of the La Niña winters that followed an El Niño winter featured a predominantly positive EPO. Based on sensitivity analysis applied to the latest guidance, there is an implied 54% probability that New York City will have a warmer than normal September. September will likely finish with a mean temperature near 68.2°.

Denver isn’t far from the Sonoran Desert. Heat can easily push through the Rockies and into the Northern Plains. There are no large water bodies to moderate the heat.

I suspect that the issue is a function of the reality that people, in general, are very poor at risk perception. Biases skew perceptions. What happened at Chernobyl and Three Mile Island looms large in perceptions of risk. In reality, when carbon pollution from fossil fuels is considered, there’s little debate. Fossil fuels are the more hazardous energy source.

Under mostly sunny skies, the temperature rose into the lower 60s at Robert Moses State Park this afternoon. A few Monarch butterflies were in flight, but the peak migration is still a little in the future, as much of the goldenrod has yet to bloom. Five photos from today:

Today, Denver hit 90°. That was the 74th time this year that the temperature reached or exceeded 90° at Denver. The prior record was 73 days, which was set in 2012. The five highest number of 90° days during a year are: 1. 74, 2020 2. 73, 2012 3. 61, 2000 4. 60, 1994 5. 59, 2018 The 30-year moving average of 90° days has also been increasing. Since 2000, Denver has added an average of 9.5 such days to its annual figure. Since 1950, the annual average has increased by just over 90%. Select statistics for the 30-year period ending in the specified years: 1950 23.3 days 1960 29.8 days 1970 29.8 days 1980 34.5 days 1990 33.8 days 2000 35.1 days 2010 37.8 days 2020 44.6 days Since recordkeeping began in 1872, Denver has had 16 years during which there were 50 or more 90° readings. 11 (69%) have occurred during 2000 or later and 6 (38%) have occurred during 2010 or later. The exceptional heat of summer 2020 and early September 2020 made this outcome possible. Denver's average high temperature during summer 2020 was 91.2°, which is the second highest figure on record. Such summers are likely to become more common in the years ahead with the average high temperature during summer likely to increase by nearly 1°F under the RCP 4.5 scenario by 2030 (and 2.9° from the 1981-2020 base figure).

Courtesy of a paper noted by @snowman19 here’s a link to a paper that might be of interest: https://www.nature.com/articles/s41612-018-0039-3

Morning thoughts... The coldest air so far this season now covers the region. Today will be partly sunny and very cool for the season. The temperature will likely struggle toward the middle 60s across the region. Likely high temperatures around the region include: New York City (Central Park): 64° Newark: 65° Philadelphia: 65° A warmup will likely commence toward the middle of next week. In terms of verification, here's how last evening's estimates worked out: Albany: 36°; Actual: 33° Allentown: 41°; Actual: 39° Boston: 48°; Actual: 46° Bridgeport: 49°; Actual: 47° Harrisburg: 47°; Actual: 43° Hartford: 42°; Actual: 37° Islip: 48°; Actual: 49° New York City: 50°; Actual: 50° Newark: 49°; Actual: 48° Philadelphia: 50°; Actual: 48° Poughkeepsie: 40°; Actual: 36° Providence: 46°; Actual: 45° White Plains: 44°; Actual: 42° Average Error: 2.2°

While Phoenix was recording its hottest month on record in August, after having set the mark in July, the United Kingdom experienced a severe heat wave in August. Here’s a link to a post written by two UK Met Office authors: https://www.carbonbrief.org/met-office-the-uks-august-2020-heatwave Excerpt: During August 2020, temperatures exceeding 34C were recorded somewhere in the UK for six consecutive days. 34C has been recorded in the UK during seven out of the last 10 years, compared to seven out of the previous 50 years from 1961 to 2010. This suggests that temperatures of 34C or higher occurring at some point during the summer are becoming a more common occurrence.

Let’s hope this is an exception. The Euro seasonal outlook is ugly.

1988-89 and 2000-01 are examples. The former had below normal snowfall. The latter was snowier than normal.

The coming weekend will be unseasonably chilly. Even Central Park could see the temperature drop below 50° this weekend for the first time in September since September 24, 2013 when the temperature fell to 47°. Tomorrow morning's low temperatures will likely be near the following values: Albany: 36° Allentown: 41° Boston: 48° Bridgeport: 49° Harrisburg: 47° Hartford: 42° Islip: 48° New York City: 50° Newark: 49° Philadelphia: 50° Poughkeepsie: 40° Providence: 46° White Plains: 44° Generally below normal readings could persist until near the middle of next week. Afterward, temperatures will moderate. There is an increasing possibility that September could wind up on the cool side of normal, which would be an uncommon event in recent cases preceding La Niña winters. Such an outcome is not assured. The highest rainfall from Hurricane Sally was 29.99" at Orange Beach, AL. The ENSO Region 1+2 anomaly was -1.0°C and the Region 3.4 anomaly was -1.0°C for the week centered around September 9. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -1.08°C and the ENSO Region 3.4 anomaly has averaged -0.75°C. La Niña conditions have developed and will likely prevail through the remainder of autumn. The SOI was +17.89. Today, the preliminary Arctic Oscillation (AO) figure was +0.407. On September 17, the MJO was in Phase 4 at an amplitude of 1.592 (RMM). The September 16-adjusted amplitude was 1.624. Since 1990, there have been 11 La Niña events, 6 of which followed an El Niño winter. 10/11 (91%) case saw warmer than normal September. All 6 following an El Niño winter were warmer than normal. September mean temperatures for New York City for those cases were: 11 cases: 69.9°; Subset of 6 cases: 70.8°; Entire 1990-2019 period: 69.0°. The September mean temperature for all La Niña and neutral-cool cases following an El Niño winter (1950-2019: n=13) was 69.9°. Since 1950, there have been five cases where a La Niña developed during June-July-August or afterward following an El Niño winter. 4/5 (80%) of those cases saw a predominant EPO+/AO+ winter pattern. The most recent such case was 2016-17. 9/10 (90%) of the La Niña winters that followed an El Niño winter featured a predominantly positive EPO. Based on sensitivity analysis applied to the latest guidance, there is an implied 49% probability that New York City will have a warmer than normal September. September will likely finish with a mean temperature near 68.1°. Finally, on September 17, Arctic sea ice extent (JAXA) was 3.735 million square kilometers. It is likely that the summer minimum figure has been reached. That figure was 3.555 million square kilometers (JAXA), which was the second lowest minimum extent on record. 2020 is the second consecutive year with a minimum extent figure below 4.000 million square kilometers and the third such year on record.

It still varies quite a bit.

Here is another paper: https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2010JD015065

Morning thoughts... A strong cold front is moving across the area. Clouds will gradually give way to partly sunny skies. Temperatures will rise mainly into the upper 60s to around 70° across the region. Likely high temperatures around the region include: New York City (Central Park): 69° Newark: 70° Philadelphia: 70° This weekend will see the coolest readings so far this season.

On JAXA, Arctic sea ice extent rose to 3.735 million square kilometers. The 2020 minimum figure was 3.555 million square kilometers. That figure will very likely be the final minimum extent for 2020.

Here’s one paper that shows increasing water vapor: https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2016JD024917 I’m not sure if NASA makes the underlying data for its cloud fraction maps public.

Today saw temperatures top out in the middle and upper 70s. However, this warmth will be short-lived. The coldest air mass so far this season will begin to overspread the region tomorrow. The coming weekend will be unseasonably chilly. Even Central Park could see the temperature drop below 50° for the first time in September since September 24, 2013 when the temperature fell to 47°. Generally below normal readings could persist into at least the last week of September. There is an increasing possibility that September could wind up on the cool side of normal, which would be an uncommon event in recent cases preceding La Niña winters. Elsewhere, Phoenix reached 109° today, which tied the daily record set in 1962. Today was also the 120th time this year that Phoenix reached 100° or above. 2020 is just the 7th year on record with 120 or more 100° readings. The last such year was 2018 with 128 days. The 30-year moving average is now 110.5 days. The 30-year moving average in 2010 was 109.6 days. Records go back to August 1895. The ENSO Region 1+2 anomaly was -1.0°C and the Region 3.4 anomaly was -1.0°C for the week centered around September 9. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -1.08°C and the ENSO Region 3.4 anomaly has averaged -0.75°C. La Niña conditions have developed and will likely prevail through the remainder of autumn. The SOI was +17.89. Today, the preliminary Arctic Oscillation (AO) figure was +0.292. On September 16, the MJO was in Phase 4 at an amplitude of 1.620 (RMM). The September 15-adjusted amplitude was 1.428. Since 1990, there have been 11 La Niña events, 6 of which followed an El Niño winter. 10/11 (91%) case saw warmer than normal September. All 6 following an El Niño winter were warmer than normal. September mean temperatures for New York City for those cases were: 11 cases: 69.9°; Subset of 6 cases: 70.8°; Entire 1990-2019 period: 69.0°. The September mean temperature for all La Niña and neutral-cool cases following an El Niño winter (1950-2019: n=13) was 69.9°. Since 1950, there have been five cases where a La Niña developed during June-July-August or afterward following an El Niño winter. 4/5 (80%) of those cases saw a predominant EPO+/AO+ winter pattern. The most recent such case was 2016-17. 9/10 (90%) of the La Niña winters that followed an El Niño winter featured a predominantly positive EPO. Based on sensitivity analysis applied to the latest guidance, there is an implied 48% probability that New York City will have a warmer than normal September. September will likely finish with a mean temperature near 68.1°. Finally,on September 16, Arctic sea ice extent (JAXA) was 3.630 million square kilometers. To date, the summer minimum figure is 3.555 million square kilometers (JAXA). Based on 2010-2019 data, the highest 25% bound was 3.742 million square kilometers. The lowest 25% bound was 3.581 million square kilometers. The lowest 10% bound is 3.465 million square kilometers. 2020 is the second consecutive year with a minimum extent figure below 4.000 million square kilometers and the third such year on record. 2020 also has, by far, the second lowest extent on record. In contrast, according to NSIDC historical data, the 1920 minimum extent was approximately 8.826 million square kilometers and the 1970 minimum extent was 8.757 million square kilometers.

Here’s the attribution report on the Siberian heat: https://www.worldweatherattribution.org/wp-content/uploads/WWA-Prolonged-heat-Siberia-2020.pdf

There was additional rainfall. However, it seems that unlike a few years ago, WPC no longer provides precipitation amounts for ongoing events.