Archives par mot-clé : Temperature

climate and geology

Study: climate was more variable during the last inter-glacial period

by Anthony Watts, October 12, 2018 in WUWT

Century-scale climate variability was enhanced when the Earth was warmer during the Last Interglacial period (129-116 thousand years ago) compared to the current interglacial (the last 11,700 years), according to a new UCL-led study.

The findings, published today in Nature Communications and funded by the Natural Environment Research Council (NERC) and the Australian Research Council (ARC), reveal that the Last Interglacial period was punctuated by a series of century-scale arid events in southern Europe and cold water-mass expansions in the North Atlantic.

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climate-debate

Ocean Temperatures Have Been Rising Since 19thC

by P. Homewood, October 12, 2018 in NotaLotofPeopleKnowThat

https://www.sciencedaily.com/releases/2012/04/120401135345.htm

 

The significance of course is that the warming of the oceans began long before any impact from CO2 emissions.

HH Lamb has written extensively about how sea temperatures in the Atlantic fell radically during the LIA. Is the warming trend since then merely a return to earlier conditions?

climate-debate

Yes, the Ocean Has Warmed; No, It’s Not ‘Global Warming’

by P. Homewood, October 10, 2018 in NotaLotofPeopleKnowThat

Contrary to recent press reports that the oceans hold the still-undetected global atmospheric warming predicted by climate models, ocean warming occurs in 100-year cycles, independent of both radiative and human influences.

At a press conference in Washington, D.C., on March 24, 2000, Dr. James Baker, Administrator of the U.S. National Oceanic and Atmospheric Administration (NOAA), announced that since the late 1940s, there “has been warming to a depth of nearly 10,000 feet in the Atlantic, Pacific, and Indian Oceans.” “In each ocean basin, substantial temperature changes are occurring at much deeper depths than we previously thought,” Dr. Baker said, as indicated by research conducted at NOAA’s Ocean Climate Laboratory. He was referring to a paper published in Science magazine that day, prepared by Sydney Levitus, John Antonov, Timothy Boyer, and Cathy Stephens, of the NOAA Center.

For 15 years, modellers have tried to explain their lack of success in predicting global warming. The climate models had predicted a global temperature increase of 1.5°C by the year 2000, six times more than that which has taken place. Not discouraged, the modellers argue that the heat generated by their claimed “greenhouse warming effect” is being stored in the deep oceans, and that it will eventually come back to haunt us. They’ve needed such a boost to prop up the man-induced greenhouse warming theory, but have had no observational evidence to support it. The Levitus, et al. article is now cited as the needed support.

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climate-debate

Scotland 800-Year Reconstruction Shows Temperatures Were As Warm Or Warmer In The Past!

by Dr. S. Lüning & Prof. F. Vahrenholtz, in NoTricksZone

How do today’s temperatures fit into the climate-historical context?

This is one of the main tasks of today’s climate research. A group of researchers led by Milos Rydval have presented a reconstruction of summer temperatures in Scotland over the past 800 years. The results were produced from tree ring examinations.

Surprisingly, the scientists found that the current level of heat in Scotland had been reached and even exceeded several times in the past. These heat spells occurred in the 14th, 16th, and 18th centuries and each spanned over several decades (Figure 1). In between there were cold phases that fit well into the context of the Little Ice Age.

What follows is the abstract of the study published in November 2017 in the journalClimate Dynamics:

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climate-debate

At IPCC talks Trump Administration emphasizes scientific “uncertainty” and “value of fossil fuels”… MAGA!

by David Middleton, October 4, 2018 in WUWT

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95% of the model runs predicted more warming than the RSS data since 1988… And this is the Mears-ized RSS data, the one in which the measurements were influenced to obtain key information (erase the pause and more closely match the surface data).

Their “small discrepancy” would be abject failure in the oil & gas industry.

The observed warming has been less than that expected in a strong mitigation scenario (RCP4.5).

Output of 38 RCP4.5 models vs observations.   The graph is originally from Carbon Brief.  I updated it with HadCRUT4, shifted to 1970-2000 baseline, to demonstrate the post-El Niño divergence.

better to know...?, climate-debate

La baisse de l’activité solaire conduit la NASA à annoncer un refroidissement climatique

by Anne Dolhein, 2 october 2018 in Reinformation.TV

La NASA – peu suspecte de climato-scepticisme – s’appuie sur de nouveaux résultats d’observations de température aux confins de l’atmosphère terrestre pour annoncer un refroidissement notable dans ces zones, lié à l’un des minima solaires les plus importants de l’ère spatiale. Il s’agit très clairement d’un refroidissement climatique entraîné par la baisse de l’activité solaire, confirmant le rôle important sinon prépondérant du soleil sur les variations de température de la planète.

« Nous constatons une tendance au refroidissement », vient ainsi de déclarer Martin Mlynczak, chercheur principal associé du centre de recherches Langley de la NASA. « Très loin de la surface de la terre, près du bord de l’espace, notre atmosphère perd de l’énergie calorifique. Si les tendances actuelles se poursuivent, on pourrait bientôt atteindre un record de froid pour notre ère spatiale », a-t-il affirmé.

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better to know...?, climate-debate

Daily Averages? Not So Fast…

by Kip Hansen, October 2, 2018 in WUWT

In the comment section of my most recent essay concerning GAST (Global Average Surface Temperature) anomalies (and why it is a method  for Climate Science to trick itself) — it was brought up [again] that what Climate Science uses for the Daily Average temperature from any weather station is not, as we would have thought, the average of the temperatures recorded for the day (all recorded temperatures added to one another divided by the number of measurements) but are, instead, the Daily Maximum Temperature (Tmax) plus the Daily Low Temperature (Tmin) added and divided by two.  It can be written out as (Tmax + Tmin)/2.

Anyone versed in the various forms of averages will recognize the latter is actually the median of  Tmax and Tmin — the midpoint between the two …

climate-debate

The ‘Trick’ of Anomalous Temperature Anomalies

by Kip Hansen, September 25, 2018 in WUWT

It seems that every time  we turn around, we are presented with a new Science Fact that such-and-so metric — Sea Level Rise, Global Average Surface Temperature, Ocean Heat Content, Polar Bear populations, Puffin populations — has changed dramatically — “It’s unprecedented!” — and these statements are often backed by a graph illustrating the sharp rise (or, in other cases, sharp fall) as the anomaly of the metric from some baseline.  In most cases, the anomaly is actually very small and the change is magnified by cranking up the y-axis to make this very small change appear to be a steep rise (or fall).

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climate-debate

A Test of the Tropical 200- to 300-hPaWarming Rate in Climate Models

by R. McKitrick and J. Christy, July 6, 2018 in AGU100

Abstract
Overall climate sensitivity to CO2
doubling in a general circulation model results from a complex
system of parameterizations in combination with the underlying model structure. We refer to this as the model’smajor hypothesis, and we assume it to be testable. We explain four criteria that a valid test should meet: measurability, specificity, independence, and uniqueness. We argue that temperature change in the
tropical 200- to 300-hPa layer meets these criteria. Comparing modeled to observed trends over the past
60 years using a persistence-robust variance estimator shows that all models warm more rapidly than
observations and in the majority of individual cases the discrepancy is statistically significant. We argue that
this provides informative evidence against the major hypothesis in most current climate models.
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climate and geology

500 Million Years of Unrelatedness between Atmospheric CO2 and Temperature

by Davis W.J., 2017 in Climate/CO2Science

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One final gem from Davis’ work is a pronouncement that follows a discussion on the lack of correlation between CO2 and temperature across the historical record, where he aptly reminds us that “correlation does not imply causality, but the absence of correlation proves conclusively the absence of causality.” Consequently, there should be no more doubt regarding the ineffectiveness of atmospheric CO2 to control or drive climate change. It is simply nothing more than a bit player, whose influence has been continually overestimated by climate alarmists. The big question now is whether or not 500 million years of these data will convince them otherwise!

from Davis 2017

Egalement: Le changement climatique : la règle en géologie

climate-debate

Heat Analysis of NOAA Data Suggests the US Is Not Seeing Increased Warming

by Leland Park, September 13, 2018 in WUWT

Given the impending global warming crisis declared by scientists, it should be easy to unambiguously demonstrate the crisis from the instrumental record. Unfortunately, when looking at the  high temperature record for the US, it does not show any warming.

Figure 1 illustrates the incremental changes in surface air temperatures based on year to year differences in station average Tmax. The data is from all active stations in the US Historical Climatology Network (USHCN) from 1895 to 2014.

The classic heat equation defines changes in heat content as being proportional to changes in temperature (ΔQ = ƒ{ΔT} ).

Thus, Figure 1 amounts to a depiction of incremental changes in heat content, without scaling in energy units. The overall net temperature change is 0, which means the net change in heat content is also zero (ΔQ = ƒ{ΔT} = ƒ{0} = 0).

Figure 1 Year to Year Heat Changes (ΔT) for the USHCN

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better to know...?, climate-debate

Empirical Evidence Shows Temperature Increases Before CO2 Increase in ALL Records

by Tim Ball, September 9, 2018 in WUWT

The question is how does the Intergovernmental Panel on Climate Change (IPCC) determine that an increase in atmospheric CO2 causes an increase in global temperature? The answer is they assumed it was the case and confirmed it by increasing CO2 levels in their computer climate models and the temperature went up. Science must overlook the fact that they wrote the computer code that told the computer to increase temperature with a CO2 increase. Science must ask if that sequence is confirmed by empirical evidence? Some scientists did that and found the empirical evidence showed it was not true. Why isn’t this central to all debate about anthropogenic global warming?

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climate and geology, climate-debate

10 New Reconstructions Show Today’s Temperatures Still Among The Coldest Of The Last 10,000 Years

by K. Richard, September 10, 2018 in NoTricksZone

Even though CO2 concentrations hovered well below 300 ppm throughout most of the Holocene, newly published paleoclimate reconstructions affirm that today’s surface temperatures are only slightly warmer (if at all) than the coldest periods of the last 10,000 years.  This contradicts the perspective that temperatures rise in concert with CO2 concentrations.

 

Bottom Graph Source: Rosenthal et al. (2013)

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climate-debate

Global Temperature Report: August 2018 – Global Temp cooling a bit to +0.19 from +0.32 in July.

by Anthony Watts, September 10, 2018 in WUWT

August Temperatures (preliminary)

Global composite temp.:  +0.19 C (+0.34 °F) above seasonal average

Northern Hemisphere.: +0.21 C (+0.38°F) above seasonal average

Southern Hemisphere.: +0.16 C (+0.29 °F) above seasonal average

Tropics.: +0.12 C (+0.22 °F) above seasonal average

 

July Temperatures (final)

Global composite temp.:  +0.32 C (+0.58 °F) above seasonal average

Northern Hemisphere.: +0.42 C (+0.76°F) above seasonal average

Southern Hemisphere.: +0.21 C (+0.38 °F) above seasonal average

Tropics.: +0.29 C (+0.52 °F) above seasonal average

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climate-debate

Media Extrapolating A Trend From A Single Data Point: 2018 Heatwave Edition

by P. Homewood, September 5, 2018 in NotaLotofPeopleKnowThat

This article in something called Inside Climate News seems to be typical of many I have seen this year:  Because we have had much attention in the media on heat waves this year, there must be an upward trend in heat waves and that is a warning signal that man-made global warming is destroying the planet.  Typical of these articles are a couple of features

  1. Declaration of a trend without any actual trend data, but just a single data point of events this year

  2. Unstated implication that there must be a trend because the author can’t remember another year when heat wave stories were so prevalent in the media

  3. Unproven link to man-made global warming, because I guess both involve warmth.

better to know...?, climate-debate

How Do The Summers Of 1976 & 2018 Compare

by  P. Homewood, September 6, 2018 in NotaLotofPeopleKnowThat

A lot of people have said they remember the summer of 1976 being hotter than this year. And they would be right.

According to CET data, at their peak temperatures went much higher and for longer than they did this summer. The only factor that kept the two summer remotely close was that in 1976 temperatures fell away during the middle of July to below average for a while.

https://www.metoffice.gov.uk/hadobs/hadcet/cetmaxdly1878on_urbadj4.dat

climate-debate

More Support for a Global Warming Hiatus

by M. Ding et al., August 27,  2018 in CO2Science 

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The results of their analysis revealed that warming in this high Arctic site had proceeded at four times the global mean rate calculated in other data sets. However, Ding et al. note that over the last decade (2005-2014), “the warming rate in Ny-Ålesund slowed to 0.03 ± 1.85°C per decade,” which is essentially indicative of no-trend in the data. Lead-lag analysis further revealed that “Ny-Ålesund and global temperature variations were remarkably consistent, with a lag time of 8-9 years.” Consequently, the researchers say that “the ‘warming hiatus’ many scientists [have] studied also appears in Ny-Ålesund, it just started later than [that observed in] other areas.”

climate-debate

Back To Reality

by P.  Homewood, September 2, 2018 in NotaLotofPeopleKnowThat

Global temperatures fell back to 0.19C in August. This means the YTD average is 0.23C, putting them back to roughly where they were in 2002.

Arctic sea ice is tracking close to 2014, which finished with one of the highest minimums in the last decade. Current extent is well above the last three years.

 

climate-debate

Hottest Summer Evah? Not According To CET.

by Paul Homewood, September 1, 208  in NotaLotofPeopleKnowThat

With one day to go, it is clear that 2018 has been one of the hottest summers on record for the UK, however, the margin between the mean temperatures at the top of the league tables (records dating back to 1910) is so small that at this point it is impossible to say if 2018 will be an outright winner.  It is very close to the record-breaking summers of 2006 (15.78C), 2003 (15.77C), and 1976 (15.77C) all of which are within 0.01C of each other.

The margin is so small that different datasets and different regions of the UK will have different ranking. Usually we will only quote statistics to the nearest 0.1C as differences smaller than this could result from small numerical differences arising from the statistical calculations. A more comprehensive analysis of the 2018 summer data will be undertaken early next week and data for summer 2018 will continue to be analysed over the coming months.

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climate-debate

@UCSUSA “Union of Concerned Scientists” doesn’t understand what “unprecedented” means when used with the word “warming”

by Anthony Watts, August 30, 2018 in WUWT

Earth’s surface has undergone unprecedented warming over the last century, and especially in this century.

Every single year since 1977 has been warmer than the 20th century average, with 16 of the 17 warmest years on record occurring since 2001, and 2016 being the warmest year on recorded history. A study from 2016 found that without the emissions from burning coal and oil, there is very little likelihood that 13 out of the 15 warmest years on record would all have happened.

Source: https://www.ucsusa.org/global-warming/science-and-impacts/science/human-contribution-to-gw-faq.html

First a definition of the word “unprecedented”:

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Note that “in this century” isn’t part of the definition. it says “never done or known before”

So in that spirit, here’s some other “unprecedented” warming in Earth’s history, via the Vostok Ice Core dataset:

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climate-debate

Harmonic Analysis of Worldwide Temperature Proxies for 2000 Years

by H.J. Lüdecke and C.O. Weiss, April 27, 2017 in TheOpenAtm.Sci.J.

Abstract

The Sun as climate driver is repeatedly discussed in the literature but proofs are often weak. In order to elucidate the solar influence, we have used a large number of temperature proxies worldwide to construct a global temperature mean G7 over the last 2000 years. The Fourier spectrum of G7 shows the strongest components as ~1000-, ~460-, and ~190 – year periods whereas other cycles of the individual proxies are considerably weaker. The G7 temperature extrema coincide with the Roman, medieval, and present optima as well as the well-known minimum of AD 1450 during the Little Ice Age. We have constructed by reverse Fourier transform a representation of G7 using only these three sine functions, which shows a remarkable Pearson correlation of 0.84 with the 31-year running average of G7. The three cycles are also found dominant in the production rates of the solar-induced cosmogenic nuclides 14C and 10Be, most strongly in the ~190 – year period being known as the De Vries/Suess cycle. By wavelet analysis, a new proof has been provided that at least the ~190-year climate cycle has a solar origin.

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climate-debate

Greenland Temperatures In 2017

by P. Homewood, July 1, 2018 in NotaLotofPeopleKnowThat

As we all know, Greenland is warming up rapidly, causing the ice sheet to melt faster and faster.

Well, according to the BBC and New York Times, at least.

Only one slight problem – the temperature record shows quite a different story.

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There is certainly no evidence of rising temperature trends, and every likelihood that temperatures will plummet again when the AMO turns cold again.

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