Archives par mot-clé : HardCrut4

unclassified

Man Made Global Warming

by P. Homewood, Apr 14, 2024 in NotaLotOfPeopleKnowThat

image

http://web.archive.org/web/20130927101652/https://www.metoffice.gov.uk/media/pdf/q/0/Paper2_recent_pause_in_global_warming.PDF

Once upon a time there was The Pause.

For a decade and a half, global temperatures stopped rising, an embarrassment for climate scientists. Even the Met Office published a long study in 2013 into the possible reasons.

But while one team at the Met Office were scratching their heads, another was busy at work eliminating the problem.

After all, if the data does not support the theory, you simply change the data.

The Met Office’s Hadley Centre, in conjunction with the disgraced Climate Research Unit at the UEA, had for years published their global temperature series known as HADCRUT3. They regarded it as the gold standard of datasets.

But just a year after the Met Office’s paper on the pause, a new version was rushed out, HADCRUT4, which conveniently removed that pause.

By 2014, when HADCRUT3 was formally replaced, the new version had added about a tenth of a degree to warming since 2000.

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climate-debate

How Bad is HadCRUT4 Data?

by Renee Hannon, October 29, 2018 in WUWT

Introduction

This post is a coarse screening assessment of HadCRUT4 global temperature anomalies to determine the impact, if any, of data quality and data coverage. There has been much discussion on WUWT about the quality of the Hadley temperature anomaly dataset since McLean’s Audit of the HadCRUT4Global Temperature publication which is paywalled. I purchased a copy to see what all the hub-bub was about, and it is well worth the $8 in my view. Anthony Watts’ review of McLean’s findings and executive summary can be found here.

A key chart for critical study is McLean’s Figure 4.11 in his report. McLean suggests that HadCRUT4 data prior to 1950 is unreliable due to inadequate global coverage and high month-to-month temperature variability. For this post, I subdivided McLean’s findings into three groups shown with added shading: Good data which covers the years post-1950. During this period global data coverage is excellent at greater than 75% and month-to-month temperature variation is low. Questionable data occurs from 1880 to 1950. During this period global data coverage ranged from 40% to 70% with higher monthly temperature variations. Poor data is pre-1880 when global coverage ranged from 14 to 25% with extreme monthly temperature variations.