Bombshell: After Fixing Errors, UK Met Office Says
2010, 2005 Hottest Years on Record, World Warming Faster Than Thought

post from ThinkProgress on 19 March 2012 07:00:04 PM. © ThinkProgress

Reuters: Setback for the ‘stalled’ global warming view advanced by ‘skeptics’

Global temperatures The UK Met Office said two years ago it had underestimated recent warming. The key reason is their Hadley/CRU (Climatic Research Unit) Temperature dataset (HadCRUT) undersampled the Arctic — the place on earth warming up the fastest.

Now the Met[eorological] Office (part of the Defence Ministry) has corrected their errors and update their temperature record (release here, video below). No longer is 1998 the hottest year on record. It has been (slightly) edged out by 2010 and 2005. As the UK Telegraph reports:

Between 1998 and 2010, temperatures rose by 0.11C, 0.04C more than previously estimated.
The new data set also shifts around the hottest years on record, so that the new temperature series, known as HadCRUT4, is more in line with other global records held by NASA and NOAA in the US. The American series had already added Arctic temperatures from extrapolated information.
Before it was thought the hottest years were 1998 followed by 2010, 2005, 2003 and 2002. The updated series puts 2010 as the hottest year on record followed by 2005, 1998, 2003 and 2006.
The main conclusions of the new temperature series remains the same ? that overall warming since 1850 has been around 0.75C and the 10 warmest years on record all occurred in the last 14 years.
The deniers haven’t gone so ballistic over a new study since we saw the Koch-Funded Berkeley temperature study ?confirm the reality of global warming? last year and conclude recent warming was ?on the high end? and speeding up. Indeed, that study made clear that the HadCRUT dataset was the outlier, as the figure on the right shows [click to enlarge].

That’s why the deniers always had a love-hate relationship with the HadCRUT data. They kept accusing the CRU scientists at the University of East Anglia, whose emails were stolen, of fudging the data. But at the same time, they kept citing the HadCRU data since it showed less warming in recent years.

Everyone but the anti-science disinformers have known for a long time that the Met Office dataset UNDERestimates — not OVERestimates — the recent global temperature rise. Their data excludes ?the place on Earth that has been warming fastest? (see ?What exactly is polar amplification and why does it matter?? and here). NASA?s James Hansen has made this point for years. The Met Office itself concluded a December 2009 analysis that ?The global temperature rise calculated by the Met Office?s HadCRUT record is at the lower end of likely warming.?

Now, as CRU Director Phil Jones explains, ”For the latest version we have included observations from more than 400 stations across the Arctic, Russia and Canada. This has led to better representation of what’s going on in the large geographical region.”

The Met Office has corrected a second mistake, an error the global sea-surface temperature dataset. Here is Peter Stott, the Met Office’s head of Climate Monitoring and Attribution, in a video explaining all the corrections:

If we look at the changes in the middle part of the century where you can see that HadCRUT4 in red is generally a bit warmer then HadCRUT3. This is because of our new analysis of the different ways in which our sea surface temperatures have been measured in time. The most important issue here is related to the particular drop off in temperatures seen at the end of the second world war in the HadCRUT3 temperatures. This was associated with the fact that following the war there were many more British ships measuring using the method of hauling in buckets over the sides of ships and this leads to cooler temperatures because of evaporative cooling of the temperatures in the bucket. These are cooler temperatures then would be measured by drifting buoys or by the engine room intakes in ships.So in this new analysis we have taken account of that and that means that the temperatures globally are slightly warmer in the middle part of the twentieth century.

Stott told the Telegraph, “?The scientific evidence is really strong that we are warming.?

Reuters put it well that this conclusion is “further undermining a sceptic view of stalled global warming.”

Finally, it always bears repeating that, as we learned in two key 2009 papers, the planet is warming from GHGs just where climate science said it would — the oceans, which is where more than 90% of the warming was projected to end up (see ?Skeptical Science explains how we know global warming is happening.?)