This is the second of four articles on the IPCC’s AR6 WG1 report. –CCD ed.
“History Is Not History Unless It Is The Truth.” This quote by Abraham Lincoln has a cautionary message similar to the more humorous Soviet maxim: “The future is certain; it is the past which is unpredictable.”
Both apply to the recent report (AR6 WG1) from the Intergovernmental Panel on Climate Change (IPCC).
Last month, we looked at how the IPCC used the concluding graph to misrepresent forecasts of global warming in the Summary for Policymakers section of the report Climate Change 2021: The Physical Sciences Basis.
We will now examine how the IPCC uses selective and altered climatic history in the introductory graphs to promote climate panic.
Figure SPM 1 is designed to convince the reader that global change has been uneventful for at least 100,000 years, and portrays recent human activity as causing temperature increases similar to a missile launch.
It is based on unknowable assumptions and intentionally hides relevant historical data.
We are going to break down both of these graphs to show that the sum of the pieces does not add up to the headline “Human influence has warmed the climate at a rate that is unprecedented in at least the last 2000 years.”
Note all the temperature data on this figure is relative to 1850 to 1900 and the discussion that follows is consistent with that reference time frame.
The blue bar on the left indicates that during the previous 100,000 years there was no significant period that was warmer than 2020.
It conveys a sense of very long-term and mostly cooler climate stability and may lead the reader to assume the rate of global warming today must also be unprecedented in the past 100,000 years.
The captioning below the diagram (not shown) indicates this 100,000-year-period of “unprecedented” warmth occurred only 6,500 years ago, which was the Holocene Maximum.
In the IPCC report of 1998 (now taken offline), this period was described as “…a relatively warm climate with summer temperatures in high northern latitudes about 3–4°C above modern values (my italics).”
That would mean the 1998 IPCC report concluded the Holocene Maximum was 4–5°C warmer in northern latitudes than from 1850 to 1900.
An example that confirms this is that passes in the Swiss Alps were open to human foot traffic during the Holocene Maximum. The same passes were heavily glaciated in the 20th century.
In the same report, Figure SPM 5 provides a global map of simulated temperature distributions for different average global warming scenarios.
A reader could estimate from these maps that 4–5° warmer northern latitude temperatures would equate to a global average temperature of 3°C higher than 1850-1900; in significant conflict with the bar graph.
The bar graph also avoids disclosing a climate change event that far exceeds any in the last 2,000 years. If the reader accepts that it has never been warmer in the past 100,000 years, they might not suspect there were recent periods of higher rates of global warming.
From 100,000 to about 15,000 years ago, the planet was firmly in an Ice Age, so the bar graph contains 85,000 years of information that’s mostly useless to the discussion of global warming.
Visually it condenses a significant amount of climate history and defers a more detailed climate history to begin at the writer’s discretion, which is the main graph of Panel (a).
If this plot began 15,000 years ago instead of in the last 2,020 years, then massive and unexplainable temperature spikes would be observed coming out of the last ice age.
Beginning 14,500 years ago, there was 12°C warming over a few centuries, then plunging back into glaciation by 12,800 years ago (called the Younger Dryas cooling period).
Then 11,500 years ago, as much as 10°C warming occurred in as little as 50 years—ten times the total warming at 20 times the rate of warming compared to current global warming. This information is conveniently hidden in the bar graph.
The main graph of Panel (a) is designed to extend the bar graph’s cooler climate stability from the year 1 AD until 1850, which then provides contrast for a missile launch trajectory of global warming from 1850 to 2020.
The reconstructed temperatures beginning in 1 AD are missing the following climate change events that are well-recorded in multi-disciplinary science (referenced to 1850-1900 temperatures):
- Roman Warm Period, which would occupy the first 535 years of the graph (warmer by 3°C or more)
- Dark Ages from 535 to 900 (same temperature)
- Medieval Warm Period from 900 to 1300 (up to 3°C warmer)
- The Little Ice Age from 1300 to 1850 (same temperature). Greenland ice core data indicates 1875 was the coldest year in the last 10,000 years.
A brief discussion on direct climatic observations during the above periods can be found at Is Carbon Dioxide An Existential Threat?
The most significant feature of the graph is that the Little Ice Age is almost eliminated but the recovery from it is intact.
This is what the 1998 IPCC report concluded: “Thus, some of the global warming since 1850 could be a recovery from the Little Ice Age rather than a direct result of human activities.”
This recovery becomes a dramatic temperature spike by representing each decade with a single data point on a temperature scale that is large and a timescale that is small.
This graph expands the timescale in an attempt to persuade the reader that current global warming must be human-caused.
It is carefully constructed to give the impression that major non-human factors were considered, while quietly excluding any undermining evidence.
Let’s start with the blue line at the bottom, which is labeled “simulated natural only (solar and volcanic).” Volcanic eruptions are known to temporarily diminish global temperatures due to blockage of the sun by aerosols, and this is the only volcanic factor the IPCC addressed (reference TS.2.2).
Since the IPCC regards CO2 as the main climate change driver, it should not be ignored that volcanoes also produce a lot of CO2. And as oceans cover 71% of the surface of the Earth, they also cover large areas of volcanic activity.
We don’t know how many subsea volcanoes (or vents) there are or how much CO2 they produce. The IPCC chose to only superficially address volcanoes before writing them off.
More importantly, the report states (TS.2.2) that “Solar activity since 1900 was high but not exceptional compared to the last 9,000 years.”
This is a controversial statement, given that during the recent Little Ice Age we can detect with much greater confidence that there were four consecutive Grand Solar Minimums (multi-decadal periods of low solar activity) and no Grand Solar Maximums (multi-decadal periods of high solar activity).
The Little Ice Age ended coincident with the commencement of the Modern Grand Solar Maximum that dominated the 20th century.
We don’t know the exact mechanisms of how changes in solar activity affect the Earth’s climate, so we cannot say that correlation is proof of causation.
But we do know that low solar activity, such as during the Little Ice Age, allows more galactic cosmic rays to reach the Earth.
In 2017 at the largest particle physics laboratory in the world, the CERN facility, an experiment proved galactic cosmic rays promote low altitude clouds on Earth.
Low clouds block some of the sun’s energy which in turn causes cooling. Since this is emerging and important climate science, it is disingenuous of the IPCC to claim solar variations are known to be insignificant in climate change.
The dismissal of solar and volcanic influences leaves the reader to assume that humans caused 1°C of observed global warming from 1850 to 1900.
A more honest assessment of the state of the knowledge of the science of climate and climatic change, which is the IPCC mandate from the United Nations, would be that the contribution of volcanoes is unknown, and while solar variations is an evolving science, it’s strongly correlated to the Little Ice Age and the recovery from it.
Figure SPM 1 sets the stage for the Summary for Policymakers by attempting to establish as fact that “Human influence has warmed the climate at a rate that is unprecedented in at least the last 2000 years.” However:
- Human influence is not the only climate change driver; evolving science in solar influence and unknowable subsea volcanic CO2 emissions are ignored.
- Human influence has warmed the climate but only back to where it was in 1300 before the start of the Little Ice Age. It is still cooler today than it was during the Holocene Maximum, the Roman Warming Period, and the Medieval Warming Period.
- Warming happened at a rate that is unprecedented in at least the last 2000 years but at a rate insignificant compared to the Younger Dryas Period 14,500 years ago.
If all the observational evidence from the last 15,000 years were presented, the reader might consider that current global warming is mostly a normal continuation of natural solar cycles, that there may be other unknowable factors, and that humans have played a minor role.
Understanding these cycles may make climate history less unpredictable and the future more certain.
The IPCC does not present this evidence. It wants to convince the reader that climate history demands the conclusion that global warming is a human-caused event. It’s not history unless it is true.
Ron Barmby (www.ronaldbarmby.ca) is a Professional Engineer with a Bachelor’s and Master’s degree, whose 40+ year career in the energy sector has taken him to over 40 countries on five continents. He recently published “Sunlight on Climate Change: A Heretic’s Guide to Global Climate Hysteria” (Amazon, Barnes & Noble) to explain in understandable terms the science of how both natural and human-caused global warming work.
Permission to use content from this article is hereby granted freely to all, provided that any such use is accompanied by attribution and link. –CCD Ed.
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