donsutherland1

The last full day of summer featured lots of sunshine and summerlike warmth. As of 3 pm, New York City had a high temperature of 86° and Newark had registered a high temperature of 88°. On the Long Island Sound, a refreshing sea breeze kicked in during the middle of the afternoon. Three photos from this afternoon:

Just so there's no confusion, everyone enjoys free speech under the U.S. Constitution. However, the guarantee of free speech does not mandate that publications grant one's views equal weight to all other views. Thus, disproved or discredited theories typically won't appear in the scientific journals. They also won't be touted in the larger mainstream media. Still, that does not mean that those who hold such beliefs cannot enjoy their right to free speech. That's a crucial distinction.

Under brilliant sunshine, temperatures rose generally into the middle 80s across the Middle Atlantic region. Baltimore, Richmond, and Sterling reached 90°. Another very warm day lies ahead for tomorrow. Courtesy of low sea ice, abnormal warmth prevails in northern Alaska. There is an implied 84% probability that Utqiagvik will record its warmest September on record. It is possible that Utqiagvik could register its first 40° mean temperature for September. The existing monthly record of 37.7° has stood since 1998. The ENSO Region 1+2 anomaly was -1.3°C and the Region 3.4 anomaly was -0.3°C for the week centered around September 11. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.65°C and the ENSO Region 3.4 anomaly has averaged -0.03°C. There remains uncertainty about the ENSO evolution later this fall. Despite the guidance, the strong cooling in Region 1+2 indicates that the prospects for a neutral-cool ENSO during the winter have increased. Such a scenario may be somewhat more likely than not. That outcome could have significant winter season implications. Since 1991 when weekly ENSO region data was available, six years have seen September record 2 or more weeks with -1.0°C or cooler weekly anomalies in Region 1+2: 1996, 1999, 2002, 2007, 2010, and 2017. 5/6 (83%) of those cases went on to feature warm December-February temperature anomalies in the Middle Atlantic and southern New England regions. 2002 had one such week ahead of what would evolve into an El Niño winter. The SOI was -19.49 today. On September 19, the SOI fell to -35.30. Often an SOI figure at or below -30.00 during the second half of September has been followed by a warmer than normal October. 2002, which saw severe October blocking during which the Arctic Oscillation fell to as low as -5.098 on October 18, was an exception. Today, the preliminary Arctic Oscillation (AO) figure was +0.481. Since 1950, there have been five prior cases when the AO averaged -0.500 or below in both July and August: 1950, 1958, 1960, 1968, and 2015. The average temperature for September was 69.1° (69.8° after adjusting for ongoing warming) and 58.9° (59.6° adjusted) for September through November in New York City. The 1981-2010 baseline normal figures are 68.0° and 57.5° respectively. The majority of cases saw a warmer than normal September and all cases featured a warmer than normal fall. Among those five cases, 2015 made a transition from predominantly negative AO values to predominantly positive ones during the fall. The combination of the AO's recent increase to the strongest positive values since April and some of the extended range guidance leave open a scenario where the AO is currently in the early stages of evolving to a predominantly positive regime. Such an outcome would also favor a warmer than normal fall and possible warm start to winter in the Middle Atlantic and southern New England regions. For now, this is merely a hypothetical discussion of one potential path toward winter. Many other variables are involved. The only idea that carries weight at this time is that the possible evolution reaffirms the longstanding signal for a warm fall. The latest EPS weeklies favor persistent ridging and warm anomalies in the East during October. The latest CFSv2 forecast for October also shows warm anomalies across much of the CONUS. Therefore, a warmer than normal September and fall appear likely. The potential for autumn 2019 to rank among the 30 warmest cases on record remains on the table. For New York City, that would translate into a September-November mean temperature of 58.8°. On September 20, the MJO was in Phase 8 at an amplitude of 1.377 (RMM). The September 19-adjusted amplitude was 1.610. Based on sensitivity analysis applied to the latest guidance, the implied probability of New York City having a warmer than normal September is approximately 86% and the probability of a monthly mean temperature of 70.0° or above is 53%. 　

One other statistic: Utqiagvik had 55 days with low temperatures of 40 or higher. The old record was 32.

The low sea ice and resulting Arctic amplification is a big reason why Utqiakvik (Barrow) had its latest first freeze on record (9/19 vs. the old record of 9/7) and has a chance of registering its first September with a mean temperature of 40° or above. The current monthly record is 37.7°.

On JAXA, Arctic sea ice extent had increased further to 4.054 million square kilometers on September 20. It is increasingly likely that the 3.964 million square kilometers measured on September 17 will prove to be the 2019 minimum figure. That would be the second lowest minimum extent on record.

To be fair, some of the big breakthroughs that led to contemporary understanding of anthropogenic climate change i.e., Hansen's work, Mann's proxy research, etc., were still years in the future. Today' scientific understanding of the fundamentals of climate change is unequivocal. Yet, there's a large gap between the urgent realities of the continuing rapid rise of atmospheric greenhouse gas concentrations and political will. For at least the next 5 or perhaps even 10 years, the unfortunate reality is that a path pretty close to the status quo is probably the base case for policy. I very much hope my dreary assessment is wrong, because delay only magnifies the scale of an already great challenge.

Thank you for the kind words. Perhaps, as the number of climate scientists expands and the field increases in scale, such a professional organization will be established. Certainly, it would be beneficial, as the AMA has played an invaluable role in the medical field. I'm not sure how a Cabinet-level department can be safeguarded from political bias from a determined President/hostile Administration. In recent years, the EPA has essentially been stripped of its climate-related work and other federal scientists involved in climate-related research have been hindered or worse (e.g., the Department of Agriculture's climate research group). Congress has been unwilling or unable to protect them.

After another cool start, temperatures rebounded this afternoon. A very warm weekend now lies ahead. Temperatures will likely reach the 80s from Washington, DC to Boston. Yesterday, Utqiagvik (formerly Barrow) experienced its first freeze of the season. That was its latest freeze on record. The prior record was September 7, 2009. As a result, that city's 85-consecutive day stretch above freezing ended. The old record was 68 consecutive days, set in 2009. Both records are likely, in large part, due to low Arctic sea ice. There is an implied 78% probability that Utqiagvik will record its warmest September on record. The existing monthly record of 37.7° has stood since 1998. The ENSO Region 1+2 anomaly was -1.3°C and the Region 3.4 anomaly was -0.3°C for the week centered around September 11. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.65°C and the ENSO Region 3.4 anomaly has averaged -0.03°C. There remains uncertainty about the ENSO evolution later this fall. Despite the guidance, the strong cooling in Region 1+2 indicates that the prospects for a neutral-cool ENSO during the winter have increased. Such a scenario may be somewhat more likely than not. That outcome could have significant winter season implications. Since 1991 when weekly ENSO region data was available, six years have seen September record 2 or more weeks with -1.0°C or cooler weekly anomalies in Region 1+2: 1996, 1999, 2002, 2007, 2010, and 2017. 5/6 (83%) of those cases went on to feature warm December-February temperature anomalies in the Middle Atlantic and southern New England regions. 2002 had one such week ahead of what would evolve into an El Niño winter. The SOI was -27.75 today. On September 19, the SOI fell to -35.30. Often an SOI figure at or below -30.00 during the second half of September has been followed by a warmer than normal October. 2002, which saw severe October blocking during which the Arctic Oscillation fell to as low as -5.098 on October 18, was an exception. Today, the preliminary Arctic Oscillation (AO) figure was +0.020. Since 1950, there have been five prior cases when the AO averaged -0.500 or below in both July and August: 1950, 1958, 1960, 1968, and 2015. The average temperature for September was 69.1° (69.8° after adjusting for ongoing warming) and 58.9° (59.6° adjusted) for September through November in New York City. The 1981-2010 baseline normal figures are 68.0° and 57.5° respectively. The majority of cases saw a warmer than normal September and all cases featured a warmer than normal fall. Among those five cases, 2015 made a transition from predominantly negative AO values to predominantly positive ones during the fall. The combination of the AO's recent increase to the strongest positive values since April and some of the extended range guidance leave open a scenario where the AO is currently in the early stages of evolving to a predominantly positive regime. Such an outcome would also favor a warmer than normal fall and possible warm start to winter in the Middle Atlantic and southern New England regions. For now, this is merely a hypothetical discussion of one potential path toward winter. Many other variables are involved. The only idea that carries weight at this time is that the possible evolution reaffirms the longstanding signal for a warm fall. The latest EPS weeklies favor persistent ridging and warm anomalies in the East during October. The latest CFSv2 forecast for October also shows warm anomalies across much of the CONUS. Therefore, a warmer than normal September and fall appear likely. The potential for autumn 2019 to rank among the 30 warmest cases on record remains on the table. For New York City, that would translate into a September-November mean temperature of 58.8°. On September 19, the MJO was in Phase 8 at an amplitude of 1.613 (RMM). The September 18-adjusted amplitude was 1.560. Based on sensitivity analysis applied to the latest guidance, the implied probability of New York City having a warmer than normal September is approximately 87% and the probability of a monthly mean temperature of 70.0° or above is 58%.

Most recent 90° or above readings in October: New Brunswick, NJ: October 9, 2007: 91° New York City-Central Park: October 6, 1941: 90° New York City-JFK: October 8, 2007: 90° New York City-LGA: October 6, 1946: 90° Newark: October 6, 1959: 91°

This overview of the carbon cycle explains the processes involved. http://www.columbia.edu/~vjd1/carbon.htm The net reduction to levels that predated those of the Eocene occurs over geological timeframes.

IMO, this study by Dr. Zhu, Dr. Tierney et al., is particularly important. The newer climate models have been showing greater warming than the prior ones for the expected RCPs. A better handle on cloud-related feedbacks, not modeling error, might be producing this outcome.

As the world's youth engage in demonstrations to break the unwillingness of policy makers to meaningfully launch a sustained effort to address the challenge of anthropogenic climate change, some of those with high profiles in the shrinking movement that rejects the overwhelming and unequivocal basis of climate change, are now launching broad ad hominem attacks against the youth, particularly 16-year-old Swede Greta Thunberg. One denier, who has no known medical degree or any expertise in the field of psychiatry, diagnosed 16-year-old Greta Thunberg, who has galvanized the international youth movement, as "mentally ill." Another dehumanized her, labeling her a "puppet" while gloating about rising global greenhouse gas emissions. Yet another mocked her as a child who enjoys "sacred status" only due to her youth. What do these ad hominem attacks by such climate change deniers as Bjorn Lomborg, Steve Milloy, and Tom Nelson say? First, they demonstrate that they lack credible evidence or knowledge to rebut the overwhelming and unequivocal body of scientific evidence for anthropogenic climate change. They cannot explain the observed warming. They cannot escape the reality that solar irradiance has not increased to produce such warming. Second, it reveals that individuals who have less exposure to the consequences of climate change than the youth simply don't care about the future to which they seek to confine the world's young people and succeeding generations. After all, by the end of the 21st century when the consequences of climate change will be growing ever more severe, those reactionaries will have long departed this world. Third, it potentially says a lot about their character and who they are as people. A recent article published in The New Republic explains the underlying dynamic that may be driving those who engage in the nasty attacks aimed at tearing down the youth, a disproportionate share of whom are female, leading today's climate change movement. As Thunberg approached America, she was followed by a tsunami of male rage. On her first day of sailing, a multi-millionaire Brexit activist tweeted that he wished a freak accident would destroy her boat. A conservative Australian columnist called her a “deeply disturbed messiah of the global warming movement,” while the British far-right activist David Vance attacked the “sheer petulance of this arrogant child.” While these examples might feel like mere coincidence to some, the idea that white men would lead the attacks on Greta Thunberg is consistent with a growing body of research linking gender reactionaries to climate-denialism... In 2014, Jonas Anshelm and Martin Hultman of Chalmers published a paper analyzing the language of a focus group of climate skeptics. The common themes in the group, they said, were striking: “for climate skeptics … it was not the environment that was threatened, it was a certain kind of modern industrial society built and dominated by their form of masculinity.” The connection has to do with a sense of group identity under threat, Hultman told me—an identity they perceive to be under threat from all sides. Besieged, as they see it, both by developing gender equality—Hultman pointed specifically to the shock some men felt at the #MeToo movement—and now climate activism’s challenge to their way of life, male reactionaries motivated by right-wing nationalism, anti-feminism, and climate denialism increasingly overlap, the three reactions feeding off of one another. That reactionaries would assail those leading a reform movement is not new. When Martin Luther King, Jr. was leading the American Civil Rights movement during the 1960s, he and many of those involved in the movement, encountered vicious attacks aimed at delegitimizing the movement and violence aimed at suppressing it altogether. Once one looks beyond the noise and ugliness of the dying climate change denial movement of today, there is reason for optimism. Today's engaged youth appear to be embarked in sustained pursuit of a long-term goal supported by overwhelming empirical evidence. In other words, the movement won't end with today's demonstration. Today's youth have also demonstrated a capacity to leverage the Internet and Social Media to organize intensively across national borders to take on what is a global, not national, challenge. This capacity will serve them well as they become of voting age and enter the political realm. That advancing scientific knowledge has prevailed across time offers the prospect that the youth will ultimately prevail in their cause. Perhaps in decades from now, just as the Segregationists were permanently discarded onto the proverbial trash heap of history, so will the climate deniers, particularly those who engaged in the vile and reprehensible conduct cited in the above examples. In stark contrast, just as Martin Luther King, Jr.'s place in history as a reformer who advanced human welfare is secure, the place of Greta Thunberg, among the other organizers of today's demonstrations, will also be secure. Most importantly, the world will be far better off from the courage, effort, and persistence of the youth who made that better world possible.

That the climate is dynamic (has always changed and would continually change absent an anthropogenic influence) does not mean that humans aren't the predominant driver of the contemporary change. The evidence of the dramatic ongoing warming and the anthropogenic nature are overwhelming and unequivocal. Solar irradiance has not materially increased since 1950. Global temperatures have decoupled from solar irradiance. Unlike with a solar driver, where all levels of the atmosphere warm on account of an increase in incoming shortwave radiation, the stratosphere has been cooling while the troposphere has been warming. That is a classic fingerprint of greenhouse gases emitting some of the earth's outgoing longwave radiation back to the surface. This imbalance is leading to warming. http://www.ces.fau.edu/nasa/module-2/how-greenhouse-effect-works.php The physical properties of carbon dioxide were discovered back in the 19th century. Their atmospheric concentration has increased dramatically from 316 ppm in 1959 to just under 409 ppm in 2018 at the Mauna Loa Observatory. No natural variables can explain this increase. Human emissions, not all of which are absorbed by carbon sinks, do. When atmospheric greenhouse gases are included, the recent warming is represented very well. There is a very high coefficient of determination between the greenhouse gases and temperature (as one would expect from the demonstrated physical properties of such gases). https://climexp.knmi.nl/imageoftheweek.png This strong relationship is part of the reason the shrinking minority who rejects the reality of anthropogenic climate change often attempt to discredit the temperature records. They have no scientifically-valid alternative explanation for the warming. Hence, they try to get around that barrier by discounting or denying the warming. Of course, even if no temperature record existed, trends in declining Arctic sea ice, migration of flora, general retreat of glaciers, rising sea level, etc., are all consistent with a warming world.

Yesterday, Utqiagvik (formerly Barrow) experienced its first freeze of the season. That was its latest freeze on record. The prior record was September 7, 2009. As a result, that city's 85-consecutive day stretch above freezing ended. The old record was 68 consecutive days, set in 2009. Both records are likely, in large part, due to low Arctic sea ice.

On September 19, Arctic sea ice extent rose further to 4.010 million square kilometers on JAXA. It is possible that the minimum extent for 2019 has been reached. Whether that is, in fact the case, will become evident in coming days.

November 22.

Arctic Sea Ice Extent: September 18, 2019 vs. September 18, 1989: Source: NSIDC

I provided one paper earlier that dealt with the accuracy issue. The temperature data can be relied on with a very high degree of confidence. At 2 sigma (> 95% confidence), the error is around 0.1°C (e.g., for GISS). Thus, for example, the decadal average mean anomaly during the last 10 years on GISS (+0.78°C) clearly was warmer than that during the 1990s (+0.39°C). The difference between the two 10-year periods was so great that one was dealing with > 99.9% confidence. Statistically, arguments that the 1990s were just as warm (or warmer) are inaccurate.

Global average temperatures and anomalies are not a single area temperature/anomaly. They are measured in thousands of areas on land and in the ocean. Thus, the hypothetical scenario, which was meant to illustrate the concept of averages in thousandths of degrees, is spot on.

Temperatures approached daily record low figures in parts of the Northeast this morning. Overall, many areas in the Middle Atlantic and southern New England regions experienced their coldest readings so far this fall. Low temperatures included: Albany: 42° (lowest since May 14); Binghamton: 42° (lowest since June 4); Boston: (lowest since May 29); Bridgeport: 47° (lowest since June 4); Danbury: 36° (lowest since April 29); Islip: 46° (lowest since June 4); New York City: 52° (lowest since May 16); Newark: 49° (lowest since May 15); Philadelphia: 53° (lowest since June 15); Poughkeepsie: 38° (lowest since April 29); Providence: 45° (lowest since May 15); and, White Plains: 43° (lowest since May 15). In the wake of this recent fairly sharp cool shot, temperatures will rebound starting tomorrow. A warmer to much warmer than normal weekend lies ahead. The ENSO Region 1+2 anomaly was -1.3°C and the Region 3.4 anomaly was -0.3°C for the week centered around September 11. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.65°C and the ENSO Region 3.4 anomaly has averaged -0.03°C. There remains uncertainty about the ENSO evolution later this fall. Despite the guidance, the strong cooling in Region 1+2 indicates that the prospects for a neutral-cool ENSO during the winter have increased. Such a scenario may be somewhat more likely than not. That outcome could have significant winter season implications. Since 1991 when weekly ENSO region data was available, six years have seen September record 2 or more weeks with -1.0°C or cooler weekly anomalies in Region 1+2: 1996, 1999, 2002, 2007, 2010, and 2017. 5/6 (83%) of those cases went on to feature warm December-February temperature anomalies in the Middle Atlantic and southern New England regions. 2002 had one such week ahead of what would evolve into an El Niño winter. The SOI value was -35.30 today. Often an SOI figure at or below -30.00 during the second half of September has been followed by a warmer than normal October. 2002, which saw severe October blocking during which the Arctic Oscillation fell to as low as -5.098 on October 18, was an exception. Today, the preliminary Arctic Oscillation (AO) figure was -1.061. A sharp rebound will very likely commence tomorrow. Since 1950, there have been five prior cases when the AO averaged -0.500 or below in both July and August: 1950, 1958, 1960, 1968, and 2015. The average temperature for September was 69.1° (69.8° after adjusting for ongoing warming) and 58.9° (59.6° adjusted) for September through November in New York City. The 1981-2010 baseline normal figures are 68.0° and 57.5° respectively. The majority of cases saw a warmer than normal September and all cases featured a warmer than normal fall. Among those five cases, 2015 made a transition from predominantly negative AO values to predominantly positive ones during the fall. The combination of the AO's recent increase to the strongest positive values since April and some of the extended range guidance leave open a scenario where the AO is currently in the early stages of evolving to a predominantly positive regime. Such an outcome would also favor a warmer than normal fall and possible warm start to winter in the Middle Atlantic and southern New England regions. For now, this is merely a hypothetical discussion of one potential path toward winter. Many other variables are involved. The only idea that carries weight at this time is that the possible evolution reaffirms the longstanding signal for a warm fall. Therefore, a warmer than normal September and fall appear likely. The potential for autumn 2019 to rank among the 30 warmest cases on record remains on the table. For New York City, that would translate into a September-November mean temperature of 58.8°. On September 18, the MJO was in Phase 8 at an amplitude of 1.561 (RMM). The September 17-adjusted amplitude was 1.201. Based on sensitivity analysis applied to the latest guidance, the implied probability of New York City having a warmer than normal September is approximately 79% and the probability of a monthly mean temperature of 70.0° or above is near 50%.

Averaging can lead to numbers in tenths, hundredths, thousandths of degrees even if the averaged numbers are whole numbers. For example, assume there is a hypothetical 1,000 stations. All but 1 record 50 degree readings. One registers a 51 degree reading. The average is 50.001 degrees, even as no thermometers measure temperature in thousandths of degrees.

Monthly and annual temperature errors within a greater than 95% confidence interval were very small 0.1 to 0.2 degrees C back in 2013. http://static.berkeleyearth.org/memos/robert-rohde-memo.pdf Since then, better ocean measurements have become available and the averaging errors are even smaller. Even at the earlier figures, one could reject the null hypothesis that the global climate had not warmed at a 95% level of confidence.

The issue doesn’t mean measuring sea ice extent or area is not science. The issue concerns limitations of satellite-based measurements and the concept of margins of error. Statistically, when error is considered, measurements within 40,000 km2 are treated as being the same.

More inaccurate information on the climate change denier front. From twitter: One of the biggest flaws in AGW theory are increased heavy rain events. Rain comes from clouds, which form when warm, moist air rises, and cools. This only happens if there's a steep drop in temp with altitude to force the temp to reach the dew point, otherwise, NO clouds form. https://twitter.com/ChrisMartzWX/status/1174553165745786880 The problem with the above claim is that the dew point is not a fixed value. That both the surface and troposphere are warming does not mean that atmospheric temperatures can no longer reach the dew point. What the literature shows is that the warmer atmosphere, which remains capable of cloud formation, holds more moisture. As a result, the frequency of intense precipitation events in parts of the world increase. Such an increased frequency has also shown up in some of the data. https://science2017.globalchange.gov/chapter/7/ Some attribution analyses related to a number of extreme precipitation events can be found at: https://www.worldweatherattribution.org/analysis/rainfall/