Watts Falsely Suggests Decade Of U.S. Temperatures Undermines Manmade Warming

Watts: “There Has Been A Cooling Trend” In The U.S. For “At Least The Last 10 Years.” Watts acknowledged that 10 years is not enough data to evaluate climate change but still cited temperatures from the past decade to suggest that a “cooling trend” in the lower 48 states raises questions about carbon dioxide's impact on the climate. From the Daily Caller post titled, “Surprise: Over the last decade, the US cooled”:

So according to NOAA's National Climatic Data Center, it seems clear that for at least the last 10 years, there has been a cooling trend in the annual mean temperature of the continental U.S. While this is not the standard 30-year period used by climatologists to determine climate for an area, it does beg the question: If carbon dioxide is in control of our climate, as many advocates claim, how could this happen? [Daily Caller, 11/08/11]

NOAA: Brief Cooling Periods Are Not Inconsistent With Long Term Warming Trend. A paper by climate experts at NOAA and the Lawrence Berkeley National Laboratory stated:

The reality of the climate system is that, due to natural climate variability, it is entirely possible to have a period as long as a decade or two of “cooling” superimposed on the longer-term warming trend due to anthropogenic greenhouse gas forcing. Climate scientists pay little attention to these short-term fluctuations as the short term “cooling trends” mentioned above are statistically insignificant and fitting trends to such short periods is not very meaningful in the context of long-term climate change. [NOAA, 4/25/09]

U.S. Global Change Research Program: “The United States Has Been Warming Significantly Over The Past 50 Years.” A report by the U.S. Global Change Research Program stated that the U.S. has warmed more than 2°F in the past 50 years and that regional and short-term fluctuations continue to occur alongside a long-term global warming trend:

Like the rest of the world, the United States has been warming significantly over the past 50 years in response to the build up of heat-trapping gases in the atmosphere. When looking at national climate, however, it is important to recognize that climate responds to local, regional, and global factors.

[...]

It is also important to recognize that at both the global and national scales, year-to-year fluctuations in natural weather and climate patterns can produce a period that does not follow the long-term trend. Thus, each year will not necessarily be warmer than every year before it, though the warming trend continues. U.S. average temperature has risen more than 2°F over the past 50 years and is projected to rise more in the future; how much more depends primarily on the amount of heat-trapping gases emitted globally and how sensitive the climate is to those emissions. [U.S. Global Change Research Program, June 2009]

Past Decade Was The Warmest On Record For The U.S. The following chart from NOAA shows that 2000-2009 was the warmest decade on record for the contiguous U.S.:

[NOAA, 1/12/10]

Chart Illustrates Perils Of Cherry-Picking Short Term Data. The following chart of global land temperature data shows that there have been many periods in recent decades that could be mistaken for the end of global warming:

[SkepticalScience.com, 11/5/11]

Research Group: Natural Climate Variability “Can Be Very Large” On Regional Scale. The National Center for Atmospheric Research stated that “the effects of human activities are superimposed on the background 'noise' of natural climate variability, which can be very large regionally,” adding:

Global warming does not mean that temperature increases are spatially uniform or monotonic: some places warm more than the average and some places cool. Regional changes in temperature are often associated with changes natural patterns (or modes) of the atmospheric and oceanic circulation, such as the El Niño/Southern Oscillation (ENSO) phenomenon. [NCAR, accessed 11/10/11]

Continental U.S. Makes Up 1.6% Of The Earth's Surface. According to NASA, the contiguous 48 states comprise “1.6% of the Earth's surface” so U.S. temperature data alone tell us nothing about global trends. [NASA, accessed 2/1/11]

Watts Accuses Scientific Agencies Of “Orwellian” Scheme To Distort Data

Watts: “There May Be More Cooling Than Meets The Eye” Due To Data Modifications. In the Daily Caller post, Watts spotlighted adjustments to the U.S. temperature record that removed 1934 from the position of “warmest year” for the country. Watts accused the government of “shenanigans” and implied that the adjustments warranted public distrust of surface temperature data:

Even worse, there may be more cooling than meets the eye due to adjustments that have been made in the data. For example, take the year 1934, long considered to be the hottest year in U.S. history. When you go back and look at data from NASA (which also uses the NOAA/NCDC data, like the new Berkeley data does), you find that things have changed: The past temperature has been modified.

[...]

Unless you live in an Orwellian world of science, how does one justify modifying the temperature history of the past?

If this were a graph of stock performance data given to investors as a prospectus and such shenanigans were discovered, the Securities and Exchange Commission would be launching an investigation. Yet, our own government is spending billions on climate change research and related programs, seemingly accepting such modified historical data without question. And they wonder why climate skeptics don't trust the surface temperature data. [Daily Caller, 11/08/11]

But Watts Had Previously Acknowledged Source Of The Changes. Despite his apparent incredulity in the Daily Caller, Watts previously acknowledged in a blog post that “the main reason for the changes were the incorporation of an additional layer of USHCN [U.S. Historical Climatology Network] adjustments by Karl et al overlaying the time-of-observation adjustments already incorporated into Hansen et al 1999” and that additional changes were the result of “adjustments in the form of USHCN2 (for US data).” USHCN Version 2 is NOAA's updated and improved dataset of U.S. temperatures, released in 2008. Time of observation adjustments are made to eliminate bias in the record that “occurs when observing times are changed from midnight to some time earlier in the day,” according to NOAA. [Watts Up With That, 11/5/11]

NOAA Adjusts Data To Remove Errors And Biases. NOAA states that the “USHCN temperature records have been 'corrected' to account for various historical changes in station location, instrumentation, and observing practice.” NOAA explained:

Version 2 data were produced using a new set of quality control and homogeneity assessment algorithms. A brief summary of version 2 processing steps is provided below. A more comprehensive summary, including discussions of the sources and magnitude of bias in the raw (unadjusted) data, is provided in Menne et al. (2009).

[...]

Adjustments applied to USHCN Version 2 data largely account for the impact of instrument and siting changes, although a small overall residual negative (“cool”) bias appears to remain in the adjusted USHCN version 2 CONUS average maximum temperature. Nevertheless, the adjusted USHCN CONUS temperatures are well aligned with recent measurements from the U.S. Climate Reference Network (USCRN). This network was designed with the highest standards for climate monitoring and has none of the siting and instrument exposure problems present in USHCN. The close correspondence in nationally averaged temperature from these two networks is further evidence that the adjusted USHCN data provide an accurate measure of the U.S. temperature. [NOAA, 3/16/10]

NASA Climatologist: Adjustment “Makes No Difference At All” In Global Temperature Records. NASA climatologist Gavin Schmidt stated via email that “all stations and all years are being continually assessed to see whether there were shifts in the records because of changes in a station location, or an instrument or practice which, if not corrected, would put a non-climatic jump or trend in the data.” He added that this is not controversial scientifically and “makes no difference at all” for the global temperature records. Schmidt also pointed out that the adjustments were transparent and thoroughly discussed within the scientific community:

[F]ar from this being something which 'no one has questioned', the issue has been the topic of many papers in the literature, notably the 2001 Hansen et al paper that applied the corrections that NOAA had made to the temperature records to fix *known* issues in the records.

[...]

Continued insinuations that because a data analysis has changed as a function of error fixes and improvements over time that the 'books must be cooked' are simply rhetorical devices that have nothing to do with the underlying science and everything to do with politics. [Email to Media Matters, 11/09/11]