When Normals Are Not Normal
The National Weather Service Is Unwittingly Obscuring the Reality of Global Warming
by Bruce Melton PE
See the abridged version on Truthout.org, July 17, 2022
In-depth references are below the article.
Summary: The National Weather Service has a periodic procedure where they recalculate the “normal” climate data presented to the public via our professional weather and media personnel every 10 years. This practice hides or masks warming because it continuously warms the so called “normal” temperatures presented on the news every night, and in the process degrades or eliminates climate change awareness.
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A friend from college didn’t remember it being this warm back in the day. We lived in a dorm at Texas A&M University. It was built in 1928 and had many windows and no air conditioning. Septembers back then were hot, but it cooled off at night and that wonderful old building held the coolness well, but it was not hot like it is today.
Today’s 1.2 degrees C (2.2 F) average global warming is now as warm as any time in the last 10,000 years. It is three times warmer than the last 2,000 years, the period when the earth systems our advanced civilization depends upon evolved. (1) This relatively small amount of warming may not seem like much but only 5 degrees C (9 F) separates the deepest of ice age cold from the climate we just warmed beyond. (2)
Some of the latest science tells us half of known climate tipping systems have activated their collapses since about 2009. Earth’s temperature has risen above the evolutionary boundaries of these systems and their collapse thresholds have been crossed. (3)
The Amazon, permafrost and Canadian forests are three Earth systems now in tipping collapse. They have flipped from carbon sequestration to emissions with greenhouse gas emissions of plausibly seven gigatons per year. This is as much as all global emissions from transportation.(4)
These collapses were activated with warming of 0.5 to 0.75 C (0.9 to 1.3 F) above normal from the late 19th century where the last 2,000 years our world’s average temperature was no warmer than 0.4 C (0.75 F) above the late 19th century. (5) But the averages themselves are misleading. For example, warming over land is twice what it is over the oceans. (6) High temperatures are another example.
In Austin, the average high temperatures in Septembers from 2017 to 2020 were 5.3 F warmer than between 1966 and 1969. (7) In other words, the normal high in early September, that was 93 degrees in our old climate, is 98 degrees today. One would think this kind of warming would have the headlines, but this is not the case and there is a good reason. The National Weather Service (NWS) has a long standing and little known statistical weather data procedure that, while being a good idea for generations, now promotes the denial of global warming.
The “normal” temperatures the National Weather Service reports are averages of the last 30 years. This is the data broadcast on the weather report on the news every night. These so-called “normal” temperatures are not at all the temperatures from our old climate. They are not from a time before our climate began to unnaturally warm. What we hear as “normal” from our faithful weather professionals is actually significantly warmed for most of us, has nothing to do with what most of us think of as “normal” and has nothing to do with our old climate where our advanced civilization evolved.
Extremely warm temperatures in Texas in December 2021 broke the 1933 monthly average temperature record by an astonishing 4.7 degrees. Normally, monthly average temperature records are broken by less than a degree or two in a stable climate; in our old normal climate. Across Texas the high temperature was 12 degrees above the state 20th century high temperature average for December. Austin’s December average high temperature was 11.5 degrees above the 30-year normal. (8)
The statistical procedure to change the normal temperature data is known in professional circles as the 30-year normals or the climatological normals, but among the public this weather data is known as our “normal” weather. (9) The reason for this data manipulation began in the 1930s with agriculture and spread into other industries as the need for historic climate data increased. (10)
The idea here was to supply agricultural and industrial communities with the latest and most accurate weather data related to temperatures, heat waves, first and last freezes, hours below freezing, peak temperature per day, week, month and year, all sorts of precipitation records, etc. The justification of the National Weather Service for this deliberate manipulation of weather data is, “a better understanding of what is happening today. Rather than assess long-term climate trends, Normals (sic) reflect the impacts of the changing climate on our day-to-day weather experience.” (11)
This strategy of changing the “normal” data for scientific accuracy worked well when our climate was stationary or not changing radically, and when a hugely significant portion of our population needed to know so they could successfully grow food for us all. But today is definitively not like the past. What NWS is doing by warming the so called “normal” temperatures hides global warming in the minds of the public. “Normal climate” today is not the average of the last 30 years, it is what our climate was before it began to radically warm.
So what is “normal” then? Climate science defines two major “normal” periods. One is “preindustrial times.” This is the period between 1850 and 1900 and is the baseline for our stable climate before we began to massively emit greenhouse gases. The other period is 1951 to 1980. NOAA describes this period as that time, “when many of today’s adults grew up, so it is a common reference that many people can remember.” (12) Earth warmed about 0.25 C (0.45 F) between 1850 to 1900 and 1951 to 1980.
The 2,000 years prior to the preindustrial period of 1850 to 1900 is quite meaningful. During this 2000 years, Earth’s temperature was very stable at no warmer than 0.4 C (0.7 F) above the 1850 to 1900 average for almost the entire 2000 years. (13) This makes our 1.2 degrees C above normal current warming three times warmer than the maximum of the last 2000 years. This 0.4 degrees C maximum temperature range represents the upper boundary of the climate where our current Earth systems evolved. It’s also known as the natural variation of our climate. It represents the evolutionary boundary of our Earth’s systems.
We have warmed Earth above the evolutionary boundaries of its systems and they are in collapse so they can re-evolve with species and mechanisms that are tolerant of the new climate. This collapse, or excursion beyond the normal, is evident in the nonlinear increase of climate and weather extremes we have all endured recently.
Collapse of these systems is directly related to climate tipping where Earth systems collapses results in loss and even reversal of environmental services. One of the most important and easily degraded environmental services is carbon sequestration, or the ability of our Earth systems to absorb carbon dioxide. This sequestration is reversed with these tipping collapses as we are now seeing in the Amazon, Canadian Forests, and permafrost and their plausible emissions of seven gigatons of greenhouse gases per year. Very importantly, these are just the first systems collapses to be studied. Similar systems across the globe are likely in collapse too, and the collapses have just begun.
The public needs to know how much warming has occurred so we can make realistic decisions about climate change. Americans trust weather professionals on climate change. Our television weather persons are the ones that provide the vast majority of us with what is our best and most trustworthy information about climate change. (14) Through their standard professional procedures, though no fault of their own, they are masking evidence of global warming.
Today in Austin, the summer (June through August) 5-year average high temperature has warmed 6 degrees, the 10-year average summer high temperature has warmed 5 degrees, but the 30-year National Weather Service “normal” has warmed only 1.6 degrees. (15). This 30-year averaging procedure not only masks warming, it understates too.
Think about what this means to the reporting of heat waves. As the NWS warms the “normal” temperatures, the heat wave diminishes in relative extremeness to us poor sweltering humans, and we don’t even realize that the NWS has created a stifling understatement through their long-held data reporting standards.
There is a valid and urgent need to use a much shorter averaging period. Warming is not going to self-restore, it is only going to continue warming nonlinearly, like it has been doing for the last hundred years.
Our historical normal temperatures (not the NWS “normals”) are from the time when our advanced civilization evolved; they come from the climate that created humankind. This climate definitively does not include the temperature “normals” of the last 30 years presented by the National Weather Service to broadcast to the entire American population. Our true normal temperatures are what the temperatures were back in the late-19th century before our greenhouse gas emissions from fossil fuels and land use changes began to substantially warm Earth.
The average summer temperature in Austin has warmed 3.9 degrees. Austin had 10.5, 100-degree days on average every year from 1900 to 1990. But on the news, weather reporters faithfully recite the NWS normal number of 100 degree days in Austin every year is 29. This is the 30-year normal from 1990 to 2020 and it is triple the actual number of 100-degree days in our old climate from the 20th century. And the more recent the past, the warmer it has become. The 20-year average in Austin from 2000 to 2020 is 33 days at 100 degrees or above and the 10-year average from 2010 to 2020 is 39 days. (16)
When historic weather statistics are removed from daily weather communications and replaced with statistics that are warmer and warmer every ten years, the results are that the public’s awareness of global warming is damaged, degraded, or simply erased.
Even more damaging, the same weather persons that tell us the current much-warmed temperatures are normal, also tells us that, yes our climate is warming.
This confusion, imperceptible to almost all of us, creates distrust, disbelief and loss of credibility with our weather professionals. What does this do to the public’s perception of climate change? When our weather persons tell us our daily temperatures are normal, then they tell us climate change is a real problem, what are we to believe? When the news keeps talking about climate change, but the weather persons tell us the daily forecast is normal, distrust grows.
How many citizens understand this is going on; that the “normal temperatures” delivered on the weather report every night are not normal? Loss of climate change awareness feeds the narrative that climate change is either not real or is not meaningful.
To see the warming, the public must see the difference between our climate today and our climate in the past. The only place Joe and Karen Sixpack see the warming is in media weather reporting and forecasting. If weather data authorities keep warming the weather data “normals,” how are we supposed to understand climate change?
In September 1966 to 1969, there were zero days over 100 degrees in Austin. From 2017 to 2020 in September there were 21 days over 100 degrees. From 1889 to 2000 in Austin there were 26 years with one or less 100-degree days. Since 2000, zero years have passed with one or less 100-degree days. (17)
One might think the urban heat island is involved, but it is the trend that matters. The urban warming trend is no different than the rural warming trend. (18) In addition, in climate science data sets the urban heat island is adjusted out of the urban temperature data by calibrating with nearby rural weather gauges like small towns near Austin; Burnet and Blanco.
In Burnet, 44 miles northwest of Austin, population 6,500, they recorded 3 days above 93 in September between 1966 and 1969, and 32 days above 93 during September between 2017 and 2020. In Blanco, 42 miles southwest of Austin, population 11,700, they saw 6 days over 93 between 1966 and 1969, and 29 between 2017 and 2020. (19)
Today, our population is no longer agrarian-based; nowhere close. In 1900, forty percent of Americans lived on farms and today one-percent live on farms. (20) The industrialists that need this information are an exceedingly small proportion of our population. Those that need this kind of up-to-date weather data can easily get it from NWS or others, but the rest of us need to know what “normal climate” really means.
With climate tipping now active and the fires, floods, windstorms, droughts; and permafrost, ice sheet, Gulf Stream, coral and polar vortex collapses, it is now profoundly important this policy of changing the “normals” be eliminated. Literally, the National Weather Service is purposefully warming the normal temperature statistics as our climate warms. They are doing this because it is a habit from the past; a habit whose time has come to end.
Back in the day in Austin we could leave our windows open summer evenings. It was cool in the forest in mid-summer. It was chilly at the beach when the sun set low. It would frost in the wintertime and all the plant people would sleep. The robins and cedar waxwings would migrate south in the fall to spend the winter with us and the live oak leaves would fall in the spring, just like normal, in our old climate. Few of these things happen today. Green plants stay green through the winter at times. Robins don’t spend the cool season with us any longer because it is too warm. Forests are hot. The beach in summer is hot even at night.
It has warmed a lot. It’s not normal. None of it is natural. Most of the warming has been recent. The rate of warming is increasing. With this warming comes nonlinearly increasing extremes and Earth systems tipping collapses. The average global temperature today is now three times warmer than the climate where our Earth systems evolved, these systems are now collapsing, and the collapses do not stabilize unless the temperature is lowered to below the tipping threshold.
When there is no threat of irreversible and societally decimating scenarios from an artificially warmed climate, sure, recalculate the normals. But when awareness of global warming is more critical than ever before, this practice of recalculating the normals is existentially dangerous.
- Warming nearly twice the maximum of the last 2000 years… The last 2000 years of the Holocene is the time period when our advanced civilization and the Earth systems that support our advanced civilization evolved. Ninety-five percent of the time during this period was no warmer than 0.4 C (0.72 F) warmer than the late 19th This period was an exceptionally stable period in our climate and represents the boundary conditions of the evolution of our Earth systems upon which our advanced civilization depends upon.
Kaufman, Holocene global mean surface, a multi-method reconstruction approach Nature Scientific Data, June 2020.
- Depths of ice age cold…
Scott, What’s the coldest the Earth’s ever been? Climate.gov, February 18, 2021.
- Half of known climate tipping systems are now active… Nine Earth systems collapses have been identified by scientists as active: Arctic sea ice, Greenland ice sheet, boreal forests, permafrost, the Gulf Stream, the Amazon, coral, the West Antarctic Ice Sheet and parts of the East Antarctic Ice Sheet. Until 2018, the Intergovernmental Panel on Climate Change (IPCC) has assumed that tipping would not occur before 5 C of warming above preindustrial times, something that the worst-case scenario put well into the 22nd century. In 2018 however, IPCC lowered this limit to between 1 and 2 C above preindustrial times in both the 1.5 C Report and the Cryosphere Report. Lenton tells us, “The Intergovernmental Panel on Climate Change (IPCC) introduced the idea of tipping points two decades ago. At that time, these ‘large-scale discontinuities’ in the climate system were considered likely only if global warming exceeded 5 °C above pre-industrial levels. Information summarized in the two most recent IPCC Special Reports (published in 2018 and in September this year) suggests that tipping points could be exceeded even between 1 and 2 °C of warming.” Climate tipping is now active greater than 100 years ahead of projections.
Lenton et al., Climate tipping points-too risky to bet against, Nature, November 27, 2019
University of Exeter Press http://www.exeter.ac.uk/news/featurednews/title_767753_en.html
- Amazon, Canadian forests and permafrost, plausibly 7 Gt emissions annually… Amazon 1 Gt annual emissions of CO2eq, Permafrost 2.3 Gt CO2eq, Canadian forests 250 megatons emissions, all annually. The Amazon and permafrost are 8 and 14 year averages and current totals likely double the stated amounts if the Amazon and permafrost were stable and not emitting at the beginning of their average period considering a linear trend, where the trends are likely nonlinear.
Transportation emissions of 7 GT CO2eq or 6.7 Gt CO2 annually…
IPCC 2013, Physical Science Basis, Chapter 8, Transport
Amazon emitting, not absorbing, 1 Gt CO2 annually… “The study found all sources of emissions produced about 1.5bn tonnes of CO2 a year, with forest growth removing 0.5bn tonnes. The 1bn tonnes left in the atmosphere is equivalent to the annual emissions of Japan.”
Carrington, Amazon rainforest now emitting more CO2 than it absorbs, Guardian, July 14, 2021.
Gatti et al., Amazonia as a carbon source linked to deforestation and climate change, Nature, July 14, 2021.
State of Canada’s Forests 2021… Emissions are down across Canada’s public managed forests to about 220 mt CO2eq from 250 mt in 2019 (2020 report). Beetle kill contribution is up about 10 percent for and continues to grow at about the same rate for the last 4 years, and double the emissions from the low point in 2012.
7 percent of Canada’s forests are owned privately.
State of Canadas Forests 2021, Natural Resources Canada.
Permafrost collapse of 2.3 Gt CO2eq annually… These emissions are the average from 2003 to 2017. Assuming permafrost was stable in 2003 with zero emissions, the annual in linear trend 2017 was double this 2.3 gigatons, and because warming is increasing nonlinearly, permafrost is plausibly release as many greenhouse gases as all of transportation globally at 7 to 9 gigatons annually, not including the increase in the trend from 2017 to present.
Natali et al., Large loss of CO2 in winter observed across the northern permafrost region, Nature Climate Change, October 21, 2019.https://www.uarctic.org/media/1600119/natali_et_al_2019_nature_climate_change_s41558-019-0592-8.pdf
- Collapses were activated with warming of 0.5 to 0.75 C (0.9 to 1.3 F)… Kaufman 2020, See reference 1.
- Warming over land is twice what it is over the ocean… Goddard Institute for Space Studies, Global Temperature over land and water.
- Weather data statistics… Statistical analysis of daily weather date at Camp Mabry, Austin and numerous locations throughout the Hill Country of Central Texas. Web-based access to climate data and information powered by the Applied Climate Information System.
Southern Regional Climate Center, Texas A&M University’s Climatology Program, Texas A&M University College of Geosciences… – https://www.srcc.tamu.edu/climate_data_portal/?product=daily_lister
- Extremely warm temperatures in Texas in December 2021 broke the 1933 monthly average temperature record by an astonishing 6.1 degrees… The state climatologist says last month was the warmest December since 1889.
Randal, December In Texas Hottest On Record In More Than 130 Years, Texas A&M University, January 3, 2022.
Austin 11.5 degrees above the 30-year normal…
Texas has hottest December on record with climate change a contributing factor, KXAN Austin, Posted: Jan 8, 2022.
- Updated 30-year reference period reflects changing climate, WMO, May 5, 2021.
- WMO Climatological Normals, World Meteorological Organization, (undated).
- NOAA Climate Normal Periods…
- Normals (sic) reflect the impacts of the changing climate on our day-to-day weather experience…
- A period when many of today’s adults grew up, so it is a common reference that many people can remember…
NOAA – https://sos.noaa.gov/catalog/datasets/temperature-anomaly-nasa-1884-2012/
- No warmer than 0.4 C (0.7 F) above the 1850 to 1900 average…
See Reference #1 Kaufman 2020
- Americans trust weather professionals on climate change…
Schwartz,The One Group of People Americans Actually Trust on Climate Change, The Atlantic, February 22, 2022.
- The 5-year average high temperature in Austin has warmed 6 degrees F in the last 30 years… but the 30-year National Weather Service “normal” has warmed only 1.6 degrees…
See reference #7, Southern Regional Climate Data.
- Austin had 10.5, 100-degree days on average every year from 1900 to 1990… ibid.
- In September 1966 to 1969, there were zero days over 100 degrees in Austin… ibid.
- The urban warming trend is no different from the rural warming trend…
Jones et al., Urbanization effects in large‐scale temperature records with an emphasis on China, Journal of Geophysical Research, May 28, 2008.
- In Burnet, 44 miles northwest of Austin, population 6,500, they recorded 3 days above 93 in September between 1966 and 1969, and 32 days above 93 during September between 2017 and 2020…
See Reference #7, Southern Regional Climate Data.
- In 1900, forty percent of Americans lived on farms and today one-percent live on farms… In 1900, just under 40 percent of the total US population lived on farms.
Jason Lusk, Food and Agricultural Economist, The Evolution of American Agriculture, June 27, 2016.
USDA Economic Research Service