Archives par mot-clé : Model(s)

Weather and Climate in the Real World

by Tim Ball, August 18, 2018 in WUWT


All the trillions of dollars spent on AGW have not improved forecasting one bit. Instead, it diverted money that could have helped those large, primary sectors of society and economy that need better and more appropriate information. It is time to close all government weather offices or at least reduce their function to data collection determined by the end users.

Why does climate sensitivity increase over time in models? A look at two possibilities

by A. Zaragoza Comendador, August 16, 2018 in WUWT


Note: if the terms used in this article seem confusing, check out the previous one.

Introduction

It’s well known that climate models show increasing sensitivity over time: for a given forcing, the true long-term temperature increase (ECS) is higher than what you’d estimate if you simply extrapolated from the past (ECS_hist). In other words, the ECS-to-ECS_hist ratio is above 1. This article tries to work out why climate models behave like that; that is to say, the variable I’m trying to explain is the ECS-to-ECS_hist ratio.

Now, there’s probably too many hyphens and underscores in the text. So it will be more readable if I clarify that, every time I talk simply about ‘correlation’, I mean the correlation of thing X with the ECS-to-ECS_hist ratio. If other kind of correlation is mentioned, I’ll say so explicitly.

The Major Change in the Global Warming Groupthink Between 1990 and 1995

byTim Ball, August 12, 2018 in WUWT


Somebody said economists try to predict the tide by measuring one wave. This puts them in the same league as climate scientists trying to predict the climate by measuring one variable, CO2. It is no surprise that an amalgam of the two, climate and economics, produces even worse results, but that is what happened early in the anthropogenic global warming (AGW) deception.

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A Global Warming Hiatus in Northeast China

by Sun X. et al., 2018 in CO2Science


Paper Reviewed
Sun, X., Ren, G., Ren, Y., Fang, Y., Liu, Y., Xue, X. and Zhang, P. 2018. A remarkable climate warming hiatus over northeast China since 1998. Theoretical and Applied Climatology 133: 579-594.

A prominent feature of all climate model projections is their prediction that temperatures should be rising in response to ever-increasing concentrations of greenhouse gases. However, for the past two decades global surface air temperatures have not warmed to the degree predicted by the models, which lack of warming has been a conundrum to the climate alarmist movement.

108 Graphs From 89 New Papers Invalidate Claims Of Unprecedented Global-Scale Modern Warmth

by K. Richard, August 2, 2018 in NoTrickZone


During 2017, there were 150 graphs from 122 scientific papers published in peer-reviewed journals indicating modern temperatures are not unprecedented, unusual, or hockey-stick-shaped — nor do they fall outside the range of natural variability.  We are a little over halfway through 2018 and already  108 graphs from 89 scientific papers undermine claims that modern era warming is climatically unusual.

For the sake of brevity, just 13 (15%) of the 89 new papers are displayed below.

The rest of the non-hockey-stick scientific papers and graphs published thus far in 2018 can be viewed by clicking the link below.

German Scientists: Chris Folland’s Findings On Climate Models “Good For a Loud Laugh”…”Pulling Tricks Like Troopers”

by Dr S. Lüning and Prof. F. Vahrenholt, July 25, 2018 in NoTricksZone


The temperature of the last 100 years was also the topic of a new publication by Folland et al. 2018. The authors are very much at home in the camp of the IPCC and had to admit that there have been phases of cooling, stagnating or even slow warming: 1896 – 1910, 1941 – 1975, and 1998 – 2013.

Climate models struggle with this because CO2 is climbing steadily. So why does climate warming stall under these conditions? Folland and his colleagues examined the models and are convinced that despite the small problems, the models function perfectly well and thus no other climate factors need to be accounted for.

In 1940s it was a bit too warm and the models were unable to reproduce this. Given, the authors say. Greenhouse gases have been responsible for almost all the warming of the last 125 years.

Now isn’t it a bit odd that the authors made absolutely no mention of the ocean cycles in the abstract? As our regular readers know, the ocean cycles run surprisingly synchronous with the fluctuations in global temperatures, i.e. the key factors here are the AMO and PDO.

PDO ocean cycle and its fluctuations in the global temperature development. Source: Book ‘Die kalte Sonne‘.

Global Temperature Rise Some 75% Lower Than Models Projected!

by P. Gosselin, July 18, 2018 in NoTricksZone


No matter how hard climate-catastrophe obsessed alarmists attempt to beat out a little doom from the data, their results still fall far way short of their projections. Moreover, the modest warming the planet has seen over the recent decades is tied more to natural cycles.

Chart: P Gosselin, using WoodForTrees data.

Ross McKitrick: All those warming-climate predictions suddenly have a big, new problem

by Ross McKitrick, June 20, 2018 in FinancialPost


One of the most important numbers in the world goes by the catchy title of Equilibrium Climate Sensitivity, or ECS. It is a measure of how much the climate responds to greenhouse gases. More formally, it is defined as the increase, in degrees Celsius, of average temperatures around the world, after doubling the amount of carbon dioxide in the atmosphere and allowing the atmosphere and the oceans to adjust fully to the change. The reason it’s important is that it is the ultimate justification for governmental policies to fight climate change.

The United Nations Intergovernmental Panel on Climate Change (IPCC) says ECS is likely between 1.5 and 4.5 degrees Celsius, but it can’t be more precise than that. Which is too bad, because an enormous amount of public policy depends on its value. People who study the impacts of global warming have found that if ECS is low — say, less than two — then the impacts of global warming on the economy will be mostly small and, in many places, mildly beneficial.

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100% Of Climate Models Prove that 97% of Climate Scientists Were Wrong!

by Eric Holthaus, May 2018 , in Climatism


SEPTEMBER 2017

Dr. Christy was 100% correct …

A landmark paper by warmist scientists in Nature Geoscience now concedes the world has indeed not warmed as predicted, thanks to a slowdown in the first 15 years of this century. One of its authors, Michael Grubb, professor of international energy and climate change at University College London, admits his past predictions of runaway warming were too alarmist.

When the facts change, I change my mind. We are in a better place than I thought.”

ANOTHER author, Myles Allen, professor of geosystem science at Oxford, confessed that too many of the mathematical models used by climate scientists to predict future warming “were on the hot side” — meaning they exaggerated.

We haven’t seen that rapid acceleration in warming after 2000 that we see in the models.” 

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How Not To Model The Historical Temperature

by Willis Eschenbach, March 24, 2018 in WUWT


Much has been made of the argument that natural forcings alone are not sufficient to explain the 20th Century temperature variations. Here’s the IPCC on the subject:

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I’m sure you can see the problems with this. The computer model has been optimized to hindcast the past temperature changes using both natural and anthropogenic forcings … so of course, when you pull a random group of forcings out of the inputs, it will perform more poorly.

The Modern Warm Period Delimited

by David Archibald, March 10, 2018 on WUWT


This recent post discussed the end of the Modern Warm Period and the year that global cooling began. That post was inspired by a comment to a post on WUWT six to eight years ago to the effect that climate is controlled by the Sun’s magnetic flux – no need to worry about much else. The comment seemed to come from a warmer scientist – they are well funded, have plenty of time on their hands, some are smart and idle curiosity would get a few looking into what controls climate. The results would not be published of course. To paraphrase Mussolini, everything within the narrative, nothing outside the narrative, nothing against the narrative. If the Sun’s magnetic flux controls climate, you don’t have to worry about what goes on under the hood – the effect of EUV on the NAO, the GCR flux, the F10.7 flux, any other flux apart from the magnetic flux (…)

A 1D Model of Global Temperature Changes, 1880-2017: Low Climate Sensitivity (and More)

by Dr Roy Spencer, February 22, 2018 in GlobalWarming


UPDATE(2/23/18): The previous version of this post had improper latitude bounds for the HadCRUT4 Tsfc data. I’ve rerun the results… the conclusions remain the same. I have also added proof that ENSO is accompanied by its own radiative forcing, a controversial claim, which allows it to cause multi-decadal climate change. In simple terms, this is clear evidence the climate system can cause its own, natural, internally-generated climate changes. This is partly what has caused recent warming, and the climate modelling community has assumed it was all human-caused.

IT’S-THE-SUN Climate Science Steamrolls Into 2018

by K. Richard, February 22, 2018 in NoTricksZone


According to the United Nations Intergovernmental Panel on Climate Change (UN-IPCC) and computer modeling, the Sun’s role in modern-era climate change checks in at somewhere slightly above nothing.

And yet it is increasingly evident that more and more scientists across the globe do not take the position that the Sun’s influence on climate change is negligible.

In 2016 and 2017, for example, over 250 papers (see here and here) linking the Sun to climate changes were published in scientific journals.

Worse than we thought’ – climate models underestimate future polar warming

by  FLORIDA MUSEUM OF NATURAL HISTORY,  January 23, 2018, in WUWT, A. Watts


The researchers published their findings this week in the Proceedings of the National Academy of Sciences.

Scientists frequently look to the Eocene to understand how the Earth responds to higher levels of carbon dioxide. During the Eocene, the concentration of carbon dioxide in the atmosphere was more than 560 parts per million, at least twice preindustrial levels, and the epoch kicked off with a global average temperature more than 8 degrees Celsius – about 14 degrees Fahrenheit – warmer than today, gradually cooling over the next 22 million years. These characteristics make the Eocene a good period on which to test our understanding of the climate system, said Laura Cotton, study co-author and curator of micropaleontology at the Florida Museum of Natural History.