Wednesday, January 20, 2016

Unprecedented Global Temperatures

The National Centers for Environmental Information released their analysis of global temperatures for December 2015 and the year as a whole and they are unprecedented in the instrumented record and "off the charts" in the sense that they almost certainly required a revising of the y-axis scale.

Let's start with the last 3 months of 2015 (Oct - Dec).  During this period, El Nino was well developed and global mean temperatures were 1.84ºF (1.02ºC) above the 20th-century average and a whopping 0.47ºF (0.26ºC) above the next highest Oct-Dec period (2014).

Source: NCEI
December 2015 in particular was the first month in the instrumented record with a temperature a full 2ºF above the 20th-century average for the month.

Source: NCEI
Now for the worst-kept secret in the climate business: 2015 was the warmest year on record, and by a pretty wide margin, reaching 1.62ºF (0.90ºC) above the 20th century average.

Source: NCEI
This extreme warmth reflects both global warming and the strength of El Nino.  The last "super El Nino" was in 1998 and if you look at the graph above, you'll see that it was the warmest year on record to that point.  However, 2015 tops 1997 by 0.49ºF (.27ºC).

And let me get this out of the way so I don't have to answer questions about it in 2017 or 2018.  After El Nino wanes, there will probably be a temporary decline in global mean temperatures after 2015 or 2016, as occurred after 1998.  This is natural climate variability in action and when it happens, it doesn't mean that global warming has stopped or paused (see Global Warming Hasn't Stopped from March 19, 2014).  We are on the global warming locomotive and it is picking up speed, even if there are some ups-and-downs in the global mean temperature from year to year.  

10 comments:

  1. Oh stop with all your nummers and sciencey mambo jumbo.

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  2. Well, I guess the good with the bad, if we get two cool winters following this El Nino, maybe it will snow at lower elevations in Ketchikan while we are here. El Nino was playing nice for the first part of winter, not it is not. Pissing warm rain all day, every day.

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    1. Dude, great photos on your blog. I almost want to bring my skis for my next visit. Almost...

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    2. This comment has been removed by the author.

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    3. You should......you can still ski to the highway at the Silvis Lake Trailhead.........

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  3. NOAA/NASA used data from heavily adjusted land-based temperature readings while excluding the satellite record, and worse, ocean temperatures

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    1. I think what you mean to say is that the NOAA and NASA records do not use satellite-retrieved SSTs. This is true because they have had problems with cold biased SSTs due to cloud contamination. They do include in situ SST measurements though, and the dataset is very close to satellite measurements and other SST analyses, nonetheless, so I'm not sure what the problem is. In terms of adjusting temperatures, all measurements need to be bias-adjusted. You can argue about how to best do that, but you cannot argue that measurements that are bias-adjusted are not valid because if you do, no measurement is valid, including satellite measurements that are even more heavily adjusted than surface measurements. Carl Mears at RSS is man enough to admit that. I remember a similar argument to yours years ago by Berkeley physicist and global warming skeptic Richard Muller, who took money from the Koch brothers to investigate the surface temperature record only to nearly reproduce other datasets: http://berkeleyearth.org/about/. Their data (raw and adjusted) and analysis code is openly provided for free, and you are free to try to prove them and the climate community consensus wrong in their methods and conclusions.

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    2. Not exactly, they don't use ANY SST data or ANY satellite data when they spout of hyped claims of the hottest year on record, they ONLY uses their manipulated surface air temperature data. You can find numerous credible scientific studies on the subject of how they have manipulated the data if you do a google search, NOAA/NASA manipulated surface temperature data is know all around the world except by those that refuse to look at it. Many countries no longer use the NOAA/NASA surface data records for climate research because the data has become useless.

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    3. Such statements are patently false. Of course they use SST data, primarily from ships and buoys ingested into ERSST. You can read about it here: https://climatedataguide.ucar.edu/climate-data/sst-data-sets-overview-comparison-table. Other SST datasets are also used, for example HadSST by the Hadley/UKMO center. It is really irrelevant though, as all SST datasets have been shown to give very similar results. All surface temperature datasets are bias adjusted (what you call manipulated). So are satellite measurements of microwave radiances. So are nearly all measurements of anything ever. No one is claiming that data is not adjusted. That is a straw man argument. I have seen bloggers claiming unfounded "data manipulation", but those are anything but credible scientific studies. If they were credible, they would be published in reputable scientific journals. Here is a great discussion on the topic of data adjustments, if you care to challenge your own beliefs: http://arstechnica.com/science/2016/01/thorough-not-thoroughly-fabricated-the-truth-about-global-temperature-data/. There is a nice plot in that discussion showing how unimportant the latest SST bias adjustment is in the NOAA and NASA datasets. Even if you ignore the NOAA and NASA datasets, all of the other surface temperature records (JMA, Berkeley, Hadley/UKMO, Cowtan and Way) show the same thing, that 2015 was easily the warmest year on record in terms of surface temperatures. You are right that 2015 is not warmest in UAH and RSS TLT datasets, and that shouldn't be dismissed, as they are datasets that should be considered like any other. But satellite datasets are also not measuring surface temperature (they measure microwave emission over a layer that does not always have the same depth or weighting) so they shouldn't necessarily show the same thing as surface temperature records, and they also need to be "manipulated" because they only take snapshots (i.e., they are not continuously monitoring any geographic location), they diurnally drift, they have changing usage of specific satellites and instruments over time, and clouds contaminate measurements. To believe heavily adjusted satellite datasets without scrutiny and to dismiss surface temperature records is simply a case of confirmation bias, and is not founded in sound science.

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    4. NOAA/NASA reported that the average surface temperature measured 2m above the surface of the earth was 13.9°C (57.0°F) in 2015. From what I understand they use the SST to approximate the 2m air temperature above the ocean surface, interestingly they use satellite data to approximate the SST for most of the ocean surface. I find it very interesting the NOAA/NASA trusts satellite data for approximating SST but ignores other satellite data that shows that 2015 was at best the third warmest year on record.

      I read the article on arstechnica.com, I agree that some of the data needs to be adjusted. Do a google search on "nasa noaa data manipulation" and you can find good articles that show how the data has been more than just adjusted.

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