HADCRUT4 and Met Office Claims

Read this article: Met Office reply to David Rose Sunday Mail article:

As we’ve stressed before, choosing a starting or end point on short-term scales can be very misleading. Climate change can only be detected from multi-decadal timescales due to the inherent variability in the climate system. If you use a longer period from HadCRUT4 the trend looks very different. For example, 1979 to 2011 shows 0.16°C/decade (or 0.15°C/decade in the NCDC dataset, 0.16°C/decade in GISS). Looking at successive decades over this period, each decade was warmer than the previous – so the 1990s were warmer than the 1980s, and the 2000s were warmer than both.”

Ok, lets look at a non-arbitrary endpoint (the last datapoint) and go back in 5 year increments.

HADCRUT4 Last 5 years colder than previous 5 years

Mean of the anomaly of the last 5 years = .45C

Mean of the anomaly of the previous 5 years = .49C

Mean of the anomaly of the previous previous 5 years = .41C

HADCRUT3 – Last 5 years colder than previous AND colder than the previous previous 5.

Mean of the anomaly of the last 5 years = .39C

Mean of the anomaly of the previous 5 years = .45C

Mean of the anomaly of the previous previous 5 years = .41C


Warming stopped. HADCRUT3 trend is negative.

IPCC predicted .2C per decade. HADCRUT4 has been created to change the negative trend of HADCRUT3 to a positive one.

But even with the “adjustments”, the last 15 years trend in HADCRUT4 is 1/6th that predicted by the IPCC.



HADCRUT4 hates 1998

Once upon a time there was a global average temperature set call HADCRUT3.

HADCRUT3 loved 1998. 4 out of the top 10 warmest months were from 1998.

year month anomaly
1998 Jul 0.671
1998 Apr 0.647
2007 Jan 0.61
2002 Mar 0.609
1998 Jun 0.606
2002 Jan 0.598
2010 Mar 0.583
2010 Apr 0.571
2003 Oct 0.566
1998 Mar 0.548

And then along came HADCRUT4 whose primary purpose seems to be to make sure the graph of the last 15 years slopes up instead of down.

HADCRUT4 hates 1998. Not only did 2 months from 1998 drop out of the top 10, but Jan 2007 was made .208C warmer than the old Jan 2007.

year month anomaly
2007 Jan 0.818
2002 Mar 0.689
2006 Dec 0.687
2010 Apr 0.673
2010 Mar 0.662
1998 Jul 0.66
2002 Jan 0.66
1998 Apr 0.611
2003 Oct 0.602
2010 Jul 0.601

Why? I have no idea.

Paul Homewood has more. Take note of his footnote. There are no new stations in Antarctica. It looks like maybe 6 new stations south of the equator … and we know it is cooling in the south.

HADCRUT4 – The Scammers Are Getting Shameless

HADCRUT4 is the new Met Office dataset designed to replaced HADCRUT3. Why do they need to replace HADCRUT3?

Because the trend for the last 15 years in HADCRUT3 is negative and therefore it must be exterminated – like the Medieval Warming Period.

The following graph compares HADCRUT4 to HADCRUT3. (Click for a larger version)

Take note of the following:

1) HADCRUT3 and HADCRUT4 overlaps until about 2002 with minor differences.

2) For some reason, after 2002, there appears to be corrections of .1 to .2C. Why was the data ok in 1997-2002 and suddenly it was so bad it had to be “corrected”.

3) What justifies a .2C adjustment up in 2007? Thats 40% higher!

4) Every place a red line is well above the blue they have adjusted up to make the the “new dataset”  hotter.

5) HADCRUT3 trend (the dashed line) was negative (-.016C/Decade). HADCRUT4 is positive (.033C/Decade).