Archives par mot-clé : Global Temperature

The Great Failure Of The Climate Models

by Tyler Durden, 26 August 2019 in ZeroHedge


….

Christy is not looking at surface temperatures, as measured by thermometers at weather stations. Instead, he is looking at temperatures measured from calibrated thermistors carried by weather balloons and data from satellites. Why didn’t he simply look down here, where we all live? Because the records of the surface temperatures have been badly compromised.

Globally averaged thermometers show two periods of warming since 1900: a half-degree from natural causes in the first half of the 20th century, before there was an increase in industrial carbon dioxide that was enough to produce it, and another half-degree in the last quarter of the century.

The latest U.N. science compendium asserts that the latter half-degree is at least half manmade. But the thermometer records showed that the warming stopped from 2000 to 2014. Until they didn’t.

In two of the four global surface series, data were adjusted in two ways that wiped out the “pause” that had been observed.

The first adjustment changed how the temperature of the ocean surface is calculated, by replacing satellite data with drifting buoys and temperatures in ships’ water intake. The size of the ship determines how deep the intake tube is, and steel ships warm up tremendously under sunny, hot conditions. The buoy temperatures, which are measured by precise electronic thermistors, were adjusted upwards to match the questionable ship data. Given that the buoy network became more extensive during the pause, that’s guaranteed to put some artificial warming in the data.

The second big adjustment was over the Arctic Ocean, where there aren’t any weather stations. In this revision, temperatures were estimated from nearby land stations. This runs afoul of basic physics.

 

A Skeptic’s Guide To Global Temperatures

by Clive Best, August 30, 2019 in ClimateChangeDispatch


Climate change may well turn out to be a benign problem rather than the severe problem or “emergency” it is claimed to be.

This will eventually depend on just how much the Earth’s climate is warming due to our transient but relatively large increase in atmospheric CO2 levels.

This is why it is so important to accurately and impartially measure the Earth’s average temperature rise since 1850. It turns out that such a measurement is neither straightforward, independent, nor easy.

For some climate scientists, there sometimes appears to be a slight temptation to exaggerate recent warming,  perhaps because their careers and status improve the higher temperatures rise.

More fake five-alarm crises from the IPCC

by Paul Driessen, August 25, 2019


UN and other scientists recently sent out news releases claiming July 2019 was the “hottest month ever recorded on Earth” – nearly about 1.2 degrees C (2.2 degrees F) “above pre-industrial levels.” That era happens to coincide with the world’s emergence from the 500-year Little Ice Age. And “ever recorded” simply means measured; it does not include multiple earlier eras when Earth was much warmer than now.

Indeed, it is simply baseless to suppose that another few tenths of a degree (to 1.5 C above post-Little Ice Age levels) would somehow bring catastrophe to people, wildlife, agriculture and planet. It is equally ridiculous to assume all recent warming has been human-caused, with none of it natural or cyclical.

Moreover, as University of Alabama-Huntsville climate scientist Dr. Roy Spencer has noted, this past July was most likely not the warmest. The claim, he notes, is based on “a limited and error-prone array of thermometers which were never intended to measure global temperature trends.”

Greenland’s ‘Record Temperature’ denied – the data was wrong

by Anthony Watts, August 12, 2019 in WUWT


From the “But, but, wait! Our algorithms can adjust for that!” department comes this tale of alarmist woe. Greenland’s all-time record temperature wasn’t a record at all, and it never got above freezing there.


First, the wailing from news media:

NYT: https://www.nytimes.com/2019/08/02/climate/european-heatwave-climate-change.html

WAPO: https://www.washingtonpost.com/news/capital-weather-gang/wp/2016/06/10/greenland-witnessed-its-highest-june-temperature-ever-recorded-on-thursday/

Climate Progress: https://thinkprogress.org/greenland-hits-record-75-f-sets-melt-record-as-globe-aims-at-hottest-year-e34e534e533e/

Polar Portal: http://polarportal.dk/en/news/news/record-high-temperature-for-june-in-greenland/


Now from the Danish Meteorological Institute (DMI), via the news website The Local, the cooler reality:

Evidence that ERA5-based Global Temperatures Have Spurious Warming

by Dr. Roy Spencer, August 6, 2019 in GlobalWarming


“Reading, we have a problem.”

As a followup to my post about whether July 2019 was the warmest July on record (globally-averaged), I’ve been comparing reanalysis datasets since 1979. It appears that the ERA5 reanalysis upon which WMO record temperature pronouncements are made might have a problem, with spurious warmth in recent years.

Here’s a comparison of the global-average surface air temperature variations from three reanalysis datasets: ERA5 (ECMWF), CFSv2 (NOAA/NCEP), and MERRA (NASA/GSFC). Note that only CFSv2 covers the full period, January 1979 to July 2019:

ERA5 has a substantially warmer trend than the other two. By differencing ERA5 with the other datasets we can see that there are some systematic changes that occur in ERA5, especially around 2009-2010, as well as after 1998:

July 2019 Was Not the Warmest on Record

by Roy Spencer, August 2, 2019 in GlobalWarming


July 2019 was probably the 4th warmest of the last 41 years. Global “reanalysis” datasets need to start being used for monitoring of global surface temperatures. [NOTE: It turns out that the WMO, which announced July 2019 as a near-record, relies upon the ERA5 reanalysis which apparently departs substantially from the CFSv2 reanalysis, making my proposed reliance on only reanalysis data for surface temperature monitoring also subject to considerable uncertainty].

 

 

See also here

1970s: Earth Warmed 0.6°C From 1880-1940 And Cooled -0.3°C From 1940-1970. Now It’s 0.1°C And -0.05°C.

by K. Richard, July 25, 2019 in NoTricksZone


About 45 years ago, the “consensus” in climate science (as summarized by Williamson, 1975) was quite different than today’s version.

1. The Medieval Warm Period was about 1°C warmer than present overall while the “largely ice-free” Arctic was 4°C warmer, allowing the Vikings to navigate through open waters because there was “no or very little ice” at that time.
2. The island of Spitsbergen, 1237 km from the North Pole and home to over 2000 people, “benefited” because it warmed by 8°C between 1900 and 1940, resulting in 7 months of sea-ice free regional waters. This was up from just 3 months in the 1800s.
3. Central England temperatures dropped -0.5°C between the 1930s to the 1950s.
4. Pack-ice off northern and eastern iceland returned to its 1880s extent between 1958 and 1975.
5. In the 1960s, polar bears were able to walk across the sea (ice) from Greenland to Iceland for the first time since the early 1900s. (They had somehow survived the 7 months per year of sea-ice-free waters during the 1920s-1940s).

 

 

Image Source: National Academy of Sciences,  Understanding Climatic Change

GLOBAL TEMPERATURE FALLING AGAIN

by Clive Best, July 27, 2019 in GWPF


The global averaged surface temperature for June 2019 was 0.62C, back down to where it was before the 2015/16 El Nino.

The global averaged surface temperature for June 2019 was 0.62C using my spherical triangulation method merging GHCNV3 with HadSST3. This is a further drop of 0.04C from May 2018. The discrepancy with GHCNV4 is however growing. V4C calculated in exactly the same way gives a June temperature of 0.75C, a rise of 0.03C,  and 0.13C warmer than V3. This difference is statistically significant.

Climate: about which temperature are we talking about?

by S. Furfari and H. Masson, July 26, 2019 in ScienceClimateEnergie


Is it the increase of temperature during the period 1980-2000 that has triggered the strong interest for the climate change issue? But actually, about which temperatures are we talking, and how reliable are the corresponding data?

1/ Measurement errors

Temperatures have been recorded with thermometers for a maximum of about 250 years, and by electronic sensors or satellites, since a few decades. For older data, one relies on “proxies” (tree rings, stomata, or other geological evidence requiring time and amplitude calibration, historical chronicles, almanacs, etc.). Each method has some experimental error, 0.1°C for a thermometer, much more for proxies. Switching from one method to another (for example from thermometer to electronic sensor or from electronic sensor to satellite data) requires some calibration and adjustment of the data, not always perfectly documented in the records. Also, as shown further in this paper, the length of the measurement window is of paramount importance for drawing conclusions on a possible trend observed in climate data. Some compromise is required between the accuracy of the data and their representativity.

2/ Time averaging errors

If one considers only “reliable” measurements made using thermometers, one needs to define daily, weekly, monthly, annually averaged temperatures. But before using electronic sensors, allowing quite continuous recording of the data, these measurements were made punctually, by hand, a few times a day. The daily averaging algorithm used changes from country to country and over time, in a way not perfectly documented in the data; which induces some errors (Limburg, 2014) . Also, the temperature follows seasonal cycles, linked to the solar activity and the local exposition to it (angle of incidence of the solar radiations) which means that when averaging monthly data, one compares temperatures (from the beginning and the end of the month) corresponding to different points on the seasonal cycle. Finally, as any experimental gardener knows, the cycles of the Moon have also some detectable effect on the temperature (a 14 days cycle is apparent in local temperature data, corresponding to the harmonic 2 of the Moon month, Frank, 2010); there are circa 13 moon cycle of 28 days in one solar year of 365 days, but the solar year is divided in 12 months, which induces some biases and fake trends (Masson, 2018).

3/ Spatial averaging

Figs. 12, 13 and 14 : Linear regression line over a single period of a sinusoid.

 

Conclusions

 

  1. IPCC projections result from mathematical models which need to be calibrated by making use of data from the past. The accuracy of the calibration data is of paramount importance, as the climate system is highly non-linear, and this is also the case for the (Navier-Stokes) equations and (Runge-Kutta integration) algorithms used in the IPCC computer models. Consequently, the system and also the way IPCC represent it, are highly sensitive to tiny changes in the value of parameters or initial conditions (the calibration data in the present case), that must be known with high accuracy. This is not the case, putting serious doubt on whatever conclusion that could be drawn from model projections.

  2. Most of the mainstream climate related data used by IPCC are indeed generated from meteo data collected at land meteo stations. This has two consequences:(i) The spatial coverage of the data is highly questionable, as the temperature over the oceans, representing 70% of the Earth surface, is mostly neglected or “guestimated” by interpolation;(ii) The number and location of theses land meteo stations has considerably changed over time, inducing biases and fake trends.

  3. The key indicator used by IPCC is the global temperature anomaly, obtained by spatially averaging, as well as possible, local anomalies. Local anomalies are the comparison of present local temperature to the averaged local temperature calculated over a previous fixed reference period of 30 years, changing each 30 years (1930-1960, 1960-1990, etc.). The concept of local anomaly is highly questionable, due to the presence of poly-cyclic components in the temperature data, inducing considerable biases and false trends when the “measurement window” is shorter than at least 6 times the longest period detectable in the data; which is unfortunately the case with temperature data

  4. Linear trend lines applied to (poly-)cyclic data of period similar to the length of the time window considered, open the door to any kind of fake conclusions, if not manipulations aimed to push one political agenda or another.

  5. Consequently, it is highly recommended to abandon the concept of global temperature anomaly and to focus on unbiased local meteo data to detect an eventual change in the local climate, which is a physically meaningful concept, and which is after all what is really of importance for local people, agriculture, industry, services, business, health and welfare in general.

Latest Global Temp. Anomaly (May ’19: +0.32°C) A Simple “No Greenhouse Effect” Model of Day/Night Temperatures at Different Latitudes

by Dr. Roy Spencer, June 7, 2019 in WUWT


Abstract: A simple time-dependent model of Earth surface temperatures over the 24 hr day/night cycle at different latitudes is presented. The model reaches energy equilibrium after 1.5 months no matter what temperature it is initialized at. It is shown that even with 1,370 W/m2 of solar flux (reduced by an assumed albedo of 0.3), temperatures at all latitudes remain very cold, even in the afternoon and in the deep tropics. Variation of the model input parameters over reasonable ranges do not change this fact. This demonstrates the importance of the atmospheric “greenhouse” effect, which increases surface temperatures well above what can be achieved with only solar heating and surface infrared loss to outer space.

Does NASA’s Latest Figures Confirm Global Warming?

by Anthony Watts, May 9, 2019 in ClimateChangeDispatch


That’s an indication of the personal bias of co-author Schmidt, who in the past has repeatedly maligned the UAH dataset and its authors because their findings didn’t agree with his own GISTEMP dataset.

In fact, Schmidt’s bias was so strong that when invited to appear on national television to discuss warming trends, in a fit of spite, he refused to appear at the same time as the co-author of the UAH dataset, Dr. Roy Spencer.

A breakdown of several climate datasets, appearing below in degrees centigrade per decade, indicates there are significant discrepancies in estimated climate trends:

  • AIRS: +0.24 (from the 2019 Susskind et al. study)
  • GISTEMP: +0.22
  • ECMWF: +0.20
  • RSS LT: +0.20
  • Cowtan & Way: +0.19
  • UAH LT: +0.18
  • HadCRUT4: +0.17

Which climate dataset is the right one? Interestingly, the HadCRUT4 dataset, which is managed by a team in the United Kingdom, uses most of the same data GISTEMP uses from the National Oceanic and Atmospheric Administration’s Global Historical Climate Network.

New satellite data confirm real world temperature cooler than climate models

by CFACT, May 2nd, 2019


Newly published data gathered by NASA’s AIRS satellite confirm the Earth is warming more slowly than has been forecast by climate activists and the United Nations Intergovernmental Panel on Climate Change (IPCC). Data gathered from 2003 through 2017 confirm temperatures remained essentially flat from 2003 through 2015, finally rising briefly as a strong El Nino formed in 2015 and lasted into 2016 (https://ggweather.com/enso/oni.htm). Even with El Nino adding an illusory warming spike at the end of the period, temperatures still rose just over 0.2 degrees during the 15-year period. That pace works out to less than 1.5 degrees of warming per century.

IPCC initial forecasts called for 0.3 degrees Celsius of warming per decade, while skeptic forecasts have tended to hover around 0.1 degrees. As temperatures warmed more slowly than IPCC predicted, IPCC reduced its forecasts to meet skeptics in the middle, moving to a predicted 0.2 degrees warming per decade. Even so, the newly published data indicate IPCC continues to forecast more warming than real-world data indicate.

2019 GLOBAL TEMPS PREDICTION: THE ENTRIES ARE IN

by GWPF, March 6, 2019


The Met Office says it’s going to get warmer this year. GWPF readers reckon not.

Back in early February, we invited readers to submit their entries for our 2019 global temperature prediction competition. The GWPF posse had soundly beaten the Met Office in last year’s competition, and you certainly seemed encouraged by your success, as there were 250 entries this time round, more than double last year’s entry.

For 2019, the Met Office have once again pushed the boat out on their predictions, suggesting that we might see a temperature rise of 0.19°C by the year end.

As you can see from the graph below, GWPF readers are a lot more cautious. The graph is a histogram of the entries, so the height of each blue bar is the number of readers making a particular prediction, the temperatures being given in terms of anomalies from the 1961-1990 average. The most common prediction was therefore for a slight decline in temperature over the course of the year, down to to 0.55°C from last year’s 0.6°C. The Met Office prediction is the grey band – they have given a single value this time round, rather than the range given in previous years.

Aerosol-driven droplet concentrations dominate coverage and water of oceanic low-level clouds

by  D. Rosenfeld et al., February 8, 2019 in Science

Reflections on cloud effects

How much impact does the abundance of cloud condensation nuclei (CCN) aerosols above the oceans have on global temperatures? Rosenfeld et al.analyzed how CCN affect the properties of marine stratocumulus clouds, which reflect much of the solar radiation received by Earth back to space (see the Perspective by Sato and Suzuki). The CCN abundance explained most of the variability in the radiative cooling. Thus, the magnitude of radiative forcing provided by these clouds is much more sensitive to the presence of CCN than current models indicate, which suggests the existence of other compensating warming effects.

WORLD COOLING – BUT RAPID WARMING FORECAST

by David Whitehouse, February 7, 2019 in GWPF


Average global temperature has been falling for the last 3 years, despite rising atmospheric CO2 levels.

 

2018 was the fourth warmest year of the instrumental period (started 1850) having a temperature anomaly of 0.91 +/- 0.1 °C – cooler than 2017 and closer to the fifth warmest year than the third. But of course there are those that don’t like to say the global surface temperature has declined.