donsutherland1

The Arctic Dipole. https://www.amap.no/documents/doc/arctic-sea-ice-movement-pattern-and-arctic-rapid-change-pattern-arctic-dipole-anomaly/973

The authors of the MWP paper did not claim that the NAO was positive throughout the duration of the MWP. When one is dealing with centennial and sub-centennial timeframes, as was the case in the paper, one is dealing with predominant tendencies over those timeframes. A positive or negative tendency does not preclude even significant variability over much shorter timeframes. Weather is day-to-day; climate is longer-term. The authors found that the western North Atlantic region was generally cold during the MWP unlike the eastern North Atlantic region. Moreover, their study of the glacier record in the Baffin Bay region on which they based their conclusion is supported by additional proxy data. They explained: Overall, beyond the high-frequency complexity, we interpret these independent proxy records to support our glacier signal, indicating regional cool conditions through the MWP, perhaps interrupted by brief warming episodes. Our glacier record does not rule out periods of decadal warming between ~975 and 1275 CE, but the down-valley persistence of glaciers through this interval indicates that any warming was not of sufficient magnitude or duration to have driven glaciers significantly up-valley. In contrast to proxy records from the western North Atlantic region, records from the eastern North Atlantic region generally support warm conditions during the MWP. Historical observations and paleo-data indicate that sea ice off the Iceland coast was not common during the MWP, and an SST reconstruction off northern Iceland depicts a sharp rise in temperatures beginning ~1000 through ~1350 CE... The authors attribute the temperature anomalies to a persistent NAO+ state. This is a persistent tendency over the timeframe they covered. For example, let's say I was writing a paper on temperatures in the CONUS during the January 2012-2020 period. Among other variables, I could argue that a persistent NAO+ was responsible for the outcome. January 2012-2020: The argument against it would be, 'You can't maintain anomalies for such a period in either direction." But that would never have been my suggestion. If one went to the daily NAO data for the period in question, one would find: % days -1.000 or below: 1% % days negative: 24% % days positive: 76% % days +1.000 or above: 20% Each of the January cases during the period had a positive NAO value. The overall average daily value was just above +0.400. Now, if one steps back from this example and substitutes the MWP for the January 2012-2020 period and, let's say, year-to-year variability for daily variability in the NAO, one can still wind up with a skewed tendency for positive values over the timeframe considered, even as annual values would be both negative or positive. Finally, Andrew Dessler was not an author of the MWP paper. His background is in chemistry and physics. The climate system is comprised not just of the atmosphere, but also the hydrosphere, biosphere, and cryosphere. There is no compelling reason that Dr. Dessler is somehow unqualified for climate science. Also, do you have any papers that refute Dr. Dessler's work? Thanks.

For purposes of further comparison, below are RCP 4.5 projections (run in 2005) and the actual outcomes for Denver’s June-August high temperatures: 2016: Projection: 88.0 (Range: 83.7-92.3); Actual: 87.9 2017: Projection: 88.1 (Range: 83.7-92.4); Actual: 87.6 2018: Projection: 88.2 (Range: 83.8-92.5); Actual: 88.6 2019: Projection: 88.3 (Range: 83.9-92.6); Actual: 87.3 2020: Projection: 88.4 (Range: 83.9-92.7); Actual: 91.2 Five-Year Averages: RCP 4.5 Projection: 88.2 2016-2020 Average: 88.5

Greenhouse gases have played the dominant role in driving the observed warming, particularly since the late 20th century. They have not produced all the warming since the mid-20th century. Recent literature has suggested that the Medieval Warm Period was regional, not global in nature. The western Atlantic region was cold. The eastern Atlantic region was warm. The NAO has been suggested as a plausible explanation for the regional temperature variation during the MWP. https://advances.sciencemag.org/content/1/11/e1500806 Also, climate models should not be viewed as serving the same function as weather models. They are not intended to make day-to-day forecasts. They should not be viewed in such a context. Some of the major uncertainties that constrain weather model forecasts are largely irrelevant at the longer timescales used by the climate models. Their forecasts are of a more general nature over longer periods of time. Globally, they have been skillful in projecting the warming that has occurred. https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2019GL085378 They have even done a reasonable job in projecting seasonal temperatures at a regional scale. As Phoenix was had a record-breaking summer, let's take a look at the last 5 summers as an example (bearing in mind that one should not use the climate models to make year-to-year forecasts, which are subject to a lot of internal variability). Below are RCP 4.5 projections (run in 2005) and the actual outcomes for Phoenix's June-August high temperatures: 2016: Projection: 106.3 (Range: 103.5-108.9); Actual: 106.2 2017: Projection: 106.4 (Range: 103.6-109.0); Actual: 106.5 2018: Projection: 106.4 (Range: 103.6-109.1); Actual: 106.0 2019: Projection: 106.5 (Range: 103.7-109.2); Actual: 106.8 2020: Projection: 106.6 (Range: 103.7-109.2); Actual: 108.6 Five-Year Averages: RCP 4.5 Projection: 106.4 2016-2020 Average: 106.8 Despite the extreme outcome of 2020--a glimpse of summers to come by 2050 according to the projections--the idea of summer high temperatures over a 5-year period, shorter than the decade-scale that is even more meaningful when dealing with climate projections, was very good.

Morning thoughts... Today will be variably cloudy and warm. The temperature will likely top out mainly in the upper 70s and lower 80s across the region. Likely high temperatures around the region include: New York City (Central Park): 78° Newark: 80° Philadelphia: 79° The temperature will likely remain above normal through the remainder of this week. Denver could make a run at 90° today. 2020 has already seen a record 74 such days there.

The 0.3 to 0.7C increase is the IPCC projection, not Curry’s. The idea that the “pause” or “hiatus” would continue into the 2030s appears to be on track to be wrong. In 2013, when the paper was published, the global temperature anomaly was +0.68C (GISS). The 2009-13 range was +0.61C to +0.72C. In 2019, the anomaly was +0.98C (2020 will finish in that vicinity). The 5-year range was +0.85C to +1.02C.

That’s not a paper, at least not something one would find in a scientific journal. It is political commentary by a political writer on a political blog. At the same time, the author’s argument extends to arguments made by political candidates e.g., Andrew Yang, not scientists, much less climate scientists. As noted previously, climate scientists have made an overwhelming and evidence-based case that the climate is warming and that anthropogenic greenhouse gas emissions are the dominant reason for that warming. In contrast, those who reject the AGW explanation have offered no plausible evidence-based framework that could explain the warming, especially after the natural forcings and global temperature trend diverged. Yet, they place a burden of proof on climate scientists that amounts to a call for certainty. In discussing the troubling persistence of “flat earth” claims, Lee McIntyre, Philosophy professor at Boston University explained, “Flat-Earthers seem to have a very low standard of evidence for what they want to believe but an impossibly high standard of evidence for what they don’t want to believe.” That description could well describe today’s climate change denial movement, which is out of scientific ammunition, and demands impossible levels of proof from climate science. In fact, that movement likely makes such demands precisely, because it has nothing on which to base its rejection of AGW except for wishes, preferences and beliefs.

With abundant sunshine, temperatures surged into the upper 70s and lower 80s across the region today. High temperatures included: Allentown: 81° Baltimore: 81° Boston: 80° Harrisburg: 84° Hartford: 79° Islip: 79° New York City: 79° Newark: 83° Philadelphia: 81° Washington, DC: 81° Tomorrow will see similar warmth. Temperatures will likely remain at generally above normal levels for the remainder of September. A cool shot is possible to open October. Phoenix has an implied 89% probability of recording just its 13th September on record with a mean temperature of 90° or above. The most recent such occurrence was 2018 with a mean temperature of 91.8°. Phoenix will very likely record its hottest June-September period on record with a four-month mean temperature of 95.3°-95.5°. That would exceed the previous June-August record of 95.1°, which was set in 2013 and tied in 2015. The existing record is 93.9°, which was set in 2011. The ENSO Region 1+2 anomaly was -0.4°C and the Region 3.4 anomaly was -0.8°C for the week centered around September 16. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.93°C and the ENSO Region 3.4 anomaly has averaged -0.68°C. La Niña conditions have developed and will likely prevail through the remainder of autumn. The SOI was +7.43. Today, the preliminary Arctic Oscillation (AO) figure was +1.089. On September 22, the MJO was in Phase 5 at an amplitude of 1.168 (RMM). The September 21-adjusted amplitude was 0.998. 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 63% probability that New York City will have a warmer than normal September. September will likely finish with a mean temperature near 68.4°.

Winter 1988-89 was somewhat warmer than normal across the Northeast and warmer than normal across the Southeast. With the exception of southern New Jersey and parts of the Delmarva, snowfall was below to much below normal. Seasonal snowfall amounts included: Atlantic City: 17.5" Boston: 15.5" New York City: 8.1" Newark: 7.5" Philadelphia: 11.2"

Morning thoughts... Much warmer weather has returned. Today will be mostly sunny and unseasonably warm. The temperature will likely top out mainly in the upper 70s and lower 80s across the region. Likely high temperatures around the region include: New York City (Central Park): 79° Newark: 82° Philadelphia: 81° The temperature will likely remain above normal through the remainder of this week.

That is a flawed paper. 1. It comes with a statement of principle that constrains objectivity right from the start. Credible scientific work does not constrain itself with political assumptions. Nevertheless that paper contained the following disclaimer on its opening page: The CO2 Coalition of climate scientists and energy economists informs the public (1) about the net beneficial impact of carbon dioxide emissions on the atmosphere, land and oceans, and (2) the net negative impact on the economy, living standards and life expectancy of reducing these emissions by restricting access to energy. 2. It builds its case from a flawed foundation including the Shaviv (2008) paper in which the inability to attribute energy absorbed/emitted by the oceans to changes in solar irradiance led the researchers not to acknowledge the dominant role greenhouse gases were playing even then in the earth’s energy imbalance, but to speculate that there was an unknown amplifying factor. That, to be kind, is an irrational conclusion. It is illogical, because the earth’s energy budget and its imbalance have been calculated. It is unscientific, because it avoids scientific understanding related to radiative forcing. 3. The paper was not peer reviewed. Not surprisingly, that paper’s conclusions did not stand the test of time. That paper was an outlier at the time it was written when it came to estimating equilibrium climate sensitivity (ECS). Subsequent research, including some newly published papers, have narrowed the range attributable to ECS. This new information has further undermined the above paper’s conclusions.

After an unseasonably cool start, a noticeable warmup commenced. Under bright sunshine, the temperature rose into the lower 70s in many parts of the region. High temperatures included: Allentown: 73° Baltimore: 73° Harrisburg: 75° Islip: 70° New York City: 71° Newark: 75° Philadelphia: 74° Washington, DC: 73° Westhampton recorded a daily and monthly record low temperature of 32°. The previous daily record was 37°, which was set in 1962. The previous September record was 33°, which was set on September 24, 1998 and tied on September 29-30, 2000 and September 18, 2013. This was also Westhampton's earliest freeze on record. The prior record was October 2, 1998, which was tied on October 2, 2009. Both cases saw a minimum temperature of 32°. Afterward, temperatures will likely remain at generally above normal levels for the remainder of September. A cool shot is possible to open October. Phoenix has an implied 83% probability of recording just its 13th September on record with a mean temperature of 90° or above. The most recent such occurrence was 2018 with a mean temperature of 91.8°. Phoenix will very likely record its hottest June-September period on record with a four-month mean temperature of 95.2°-95.4°. The existing record is 93.9°, which was set in 2011. The ENSO Region 1+2 anomaly was -0.4°C and the Region 3.4 anomaly was -0.8°C for the week centered around September 16. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.93°C and the ENSO Region 3.4 anomaly has averaged -0.68°C. La Niña conditions have developed and will likely prevail through the remainder of autumn. The SOI was +12.72. Today, the preliminary Arctic Oscillation (AO) figure was +2.183. On September 21, the MJO was in Phase 5 at an amplitude of 0.999 (RMM). The September 20-adjusted amplitude was 0.878. 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 61% probability that New York City will have a warmer than normal September. September will likely finish with a mean temperature near 68.4°.

The Younger Dryas cooling may have been kicked off by a comet or asteroid impact. One paper that assesses that hypothesis is below: https://cosmictusk.com/wp-content/uploads/The-Younger-Dryas-impact-hypothesis-a-critical-review.pdf It should also be noted that the data is for central Greenland, not the world. In addition, the graph ends at 1855.

Actually, I was referring to the counterproductive course initiated by the United States beginning in January 2017 with the withdrawal from the Paris Agreement and rollback of regulations that has been occurring since then.

Yes.

The latest freeze was May 22, 2002. This year’s last freeze was May 21 when the temperature fell to 29 degrees, tying the record set in 2002.

Yes, it was the earliest freezing temperature at FOK. The prior record was set on October 2, 1998 and tied on October 2, 2009.

On the recent policy path that was launched in 2017, that’s a plausible outcome. I suspect some of the adverse changes that were made will be reversed by new leadership in coming years.

The status quo tends to be “sticky” for lack of a better term. When companies, countries, or societies have done well under the status quo, complacency sets in and that hardens their determination to preserve the status quo, even when developments render it unsustainable and its extension leads to worse outcomes. It’s too soon to be sure about the U.S. as a whole, but status quo thinking currently constrains U.S. policy. Efforts to move away from the status quo are subjected to defeatist “can’t be done” thinking. Had today’s thinking that thwarts effective climate change policies and a rapid shift away from fossil fuels defined the nation’s effort during World War II, the Allied countries would likely have lost the war. Had it defined things at the time the Apollo Project was launched, humans would still be looking to the future when they could set foot on the moon. Had it constrained the Ozone Hole and Acid Rain responses, both problems would have continued to grow worse.

What one is witnessing in this thread, unless I am somehow misreading things, is a general unwillingness to consider evidence that is inconsistent with beliefs and unflinching support for those beliefs despite overwhelming evidence (including numerous peer-reviewed papers) and the case made to demonstrate that such beliefs are flawed. In contrast, the alternative to AGW has virtually no support in the literature (and none that I could find in the recent literature) and it cannot explain the warming that has taken place since 1950, and especially from the late 20th century onward. Nevertheless, all that is largely ignored or dismissed. Those approaches of maintaining flawed belief in spite of the evidence are more consistent with dogma than science. Science is based on evidence and it is responsive to new empirical information (conclusions can and do change when there is sufficient credible evidence to justify such changes). This responsiveness to better information/discovery is what has allowed science to advance in a way that has expanded human understanding/knowledge and made possible much of the human progress that has been achieved.

My principal concern is that he will be working under the unqualified David Legates who is a well-known denier of climate change. That will increase risks that the NOAA could be diverted from its scientific work onto anti-scientific political paths. In turn, such a development could undercut the NOAA's credibility, which would be damaging for public safety, etc.

For those who are interested, JFK had a low temperature of 47 and LGA had a low of 55.

Morning thoughts... Today started off with very chilly and, in some cases, near record low temperatures. Minimum temperatures included: Albany: 32°; Allentown: 36°; Bridgeport: 43°; Boston: 45°; Islip: 43°; New York City: 48°; Newark: 46°; Philadelphia: 47°; Poughkeepsie: 33°; Providence: 45°; Westhampton: 32°; and, White Plains: 42°. Under bright sunshine, a noticeable warmup should commence today. The temperature will likely top out mainly in the lower 70s across the region. Likely high temperatures around the region include: New York City (Central Park): 72° Newark: 74° Philadelphia: 73° Above normal temperatures will likely continue through the remainder of this week.

The chart displayed radiative forcing. Atmospheric methane leads to a modest increase in stratospheric water vapor via oxidation. The maximum amount of tropospheric water vapor is a function of temperature. It increases at roughly 7% for every 1 degree C rise in temperature. Climate models incorporate changes in water vapor, so water vapor is not ignored. This increase in water vapor is one reason why climate scientists have correctly projected an increase in intense precipitation events. But, by definition, that is a feedback and it is one that amplifies the warming. Stating that it is a feedback is a fact, not a “cop out.” If one wants to argue that the increase in tropospheric water vapor is the equivalent of an indirect anthropogenic forcing, that’s not far-fetched, as its observed increase is the result of a temperature rise. In turn, that temperature rise is predominantly the result of rising anthropogenic greenhouse gases, not natural forcings or other natural processes.

No one expects that proxy data would be as precise as the instrument data. But the agreement among the proxies gives one confidence that they provide reasonable insight into past climate regimes. Below is a chart of the forcings (1980-2011): Source: IPCC The anthropogenic greenhouse gases explain most of the energy imbalance and warming that has occurred since 1980. Solar irradiance had a net negative (cooling) contribution. Finally, scientists are in strong consensus about the role anthropogenic greenhouse gas emissions have played in driving the energy imbalance and warming. Uncertainties about feedbacks and other details exist, but there is strong (95% confidence in the last IPCC report and likely to be 99%-100% confidence in the upcoming one) about the primary cause of those developments.