Evidence Mounts that the Earth’s Current Temperature Is Not Unusual
Climate Change Weekly #377
Even most climate alarmists begrudgingly acknowledge the Earth has experienced warmer periods than at present, such as, but not exclusive to, the age of reptiles and dinosaurs. Contrary to the “world will end” disaster claims made by climate alarmist politicians, progressive activists, and academic and corporate crony profiteers, life was fecund during these periods, with a tremendous variety of plants and animal species thriving.
Leaving ancient history behind, research has also repeatedly shown numerous periods during the present interglacial have been as warm as or warmer than it is at present. These warmer periods contributed to the rise of agricultural societies and human civilizations with large permanent settlements (which have recently morphed into megalopolises) and modern nation-states. Proxy data from tree rings, shell middens, pollen trapped in peat, fossilized remains, and oral and written historical records all show not only that global temperatures have been as warm as or warmer than today, but also that all of these warm periods have been a boon for life, including the expansion of human communities.
More evidence for relatively recent warm periods in history has recently been found in frozen Antarctica, of all places, and in Norway, on opposite sides of the globe. Scientists doing research in Antarctica report they have discovered perfectly preserved, 800-year-old penguin remains exposed by a patch of melting ice along the Antarctic coast.
In an article published in the peer-reviewed journal Geology, scientists report they discovered what appeared to be the fresh remains of Adelie penguins in a region where penguins are not known to live. Carbon dating showed the penguin remains were approximately 800 years old, implying the remains had only recently been exposed by thawing ice. Further analysis of the site showed penguins had colonized and abandoned the site multiple times between 800 and 5,000 years ago.
Scientists found the most recent period of penguin colonization began at the beginning of the Medieval Warm Period (approximately 900 A.D.) and ended at the beginning of the Little Ice Age (approximately 1200 A.D.). Penguins are currently unable to inhabit the area where the frozen corpse was found because “fast ice” (ice that extends from the Antarctic shore many miles out into the ocean) prevents them from accessing the ocean for food from shore. During the warmth of the Medieval Warm Period, the absence of fast ice allowed penguins to colonize and nest in the area for hundreds of years.
Half a world away, in the slowly thawing mountain passes of Norway, scientists have also recently uncovered what the researchers involved have labeled a “Viking highway,” a route the ancient peoples inhabiting the region used to travel regularly. A route, importantly for my point, that had for approximately 2,000 years been covered by snow and ice that expanded as the region’s climate shifted from a relatively warm period, comparable to present temperatures, to a colder period during which “permanent” thick snow and ice cover formed, erecting the equivalent of a “highway closed” sign.
The research was published in the journal Antiquity. Archaeologist Lars Holger Pilø, who led the research, describes some his team’s findings in National Geographic. The discoveries include “more than 1,000 artifacts literally frozen in time”:
Dating from around 300 to 1500 A.D., the artifacts tell the story of a mountain pass that served as a vital travel corridor for settlers and farmers moving between permanent winter settlements along the Otta River in southern Norway and higher-elevation summer farms farther south. And as they traveled across the rough terrain, these bygone travelers left behind everything from horseshoes to kitchen tools to items of clothing. As snow collected over the centuries, those forgotten objects were preserved in what eventually became the Lendbreen ice patch.
As with the “permanent” Viking settlements discovered in Greenland, the people who in ancient times travelled this corridor were forced to abandon it when the warm temperatures that made traversing it possible gave way to a significant and dangerous cooling.
Numerous other frozen and near-perfectly preserved human and animal corpses have been discovered in Arctic and glacial alpine regions in recent decades as the Earth has modestly warmed.
The most famous of these, perhaps, is the frozen human mummy scientists call Otzi, which hikers discovered in 1991 in a then-recently thawed area of the northern Italian Alps. Analysis of the mummy’s clothing, body, stomach contents, and the plants found frozen around it indicate Otzi died, was nearly flash-frozen in place, and then covered over by and ice- and snow-driven glacial expansion more than 5,300 years ago, suggesting the Earth was as warm, and the snow and ice extent as low, when he died as now.
Elsewhere in the Italian Alps, an alpine skier who was hiking in the mountains in Val Aurina, South Tyrol, Italy discovered a frozen chamois (a species of wild mountain goat) carcass jutting out of the ice. The goat’s frozen remains were dated at more than 400 years old, meaning it died either in the middle of the Little Ice Age or shortly after its advent, as the snow line and glaciers were expanding in the Alps, only to be partially uncovered now.
Additional evidence demonstrating areas that became frozen wastelands periodically during the present interglacial have been as warm or warmer in the relatively recent past as they are at present came from two studies published in late 2019, which I summarized in Climate Change Weekly 347.
In one study, published in the December 3, 2019 edition of Geophysical Research Letters, scientists using paleo-temperature reconstructions of summer temperatures from materials from three lakes on the Svalbard archipelago jutting into the Arctic Ocean, found evidence the Arctic during the Early Holocene, from 11,700 through 8,200 years BP, experienced relatively rapid increases and declines in temperatures. This research showed temperatures in the region often exceeded both currently recorded temperatures and those projected by the Intergovernmental Panel on Climate Change to occur even under its worst-case scenarios, for hundreds of years at a time.
According to the research, a peak warmth occurred approximately 10,000 years BP, at which time temperatures in the region were estimated to be 7 degrees Celsius (℃) warmer than today.
According to a second paper, published in the journal Arctic, Antarctic, and Alpine Research, researchers used pollen samples from lake sediment cores to calculate temperature changes over the past 1,000 years on Prince of Wales Island, Nunavut, in the Canadian Arctic, to understand climate change in the region. The scientists found the climate has been quite variable, with vegetation changing and shifting several times during the millennium.
In particular, although there has been a long-term cooling trend during the common era (CE), particularly over the past 1,000 years, vegetation changes indicate a great deal of climate variability, with especially significant changes during the warm Medieval Climate Anomaly from approximately 1090 to 1250 CE, when estimated vegetation expansion indicates temperatures were as high as or higher than today, and a sustained cold period from 1800 through 1915 CE even as the Little Ice Age was waning, the study found.
Carbon dating doesn’t lie. Though the exact dates of the deaths of these humans and animals, and the times of the artifacts that have recently been uncovered from their frozen graves, cannot be determined, their recent exposure from the ice and snow indicates the periods in which they died, or shortly before, were as warm as or warmer than now, and that our current snow and ice conditions are only now approaching the conditions that prevailed at the time they died or were discarded.
— H. Sterling Burnett
IN THIS ISSUE …
TEMPERATURE SHIFTS HAVE DRIVEN CO2 CHANGES HISTORICALLY … WARMER, WETTER WORLD OPTIMAL FOR LIFE
TEMPERATURE SHIFTS HAVE DRIVEN CO2 CHANGES HISTORICALLY
New research published in the peer-reviewed journal Sci confirms what past research has also shown: historically, temperature shifts have most often preceded increases or declines in carbon dioxide concentrations, indicating carbon dioxide levels don’t control temperature.
In “Atmospheric Temperature and CO2: Hen-or-Egg Causality?” scientists from universities in Greece and Poland undertook extensive statistical probability analyses to determine what kind of causal relationship existed between global temperatures and atmospheric carbon dioxide concentrations. They conclude temperatures most often drive carbon dioxide (CO2) changes, not the other way around.
The paper first summarizes the paleoclimate record, which clearly shows CO2 changes have historically followed temperature changes by about 1000 years.
Examining the sequential relationship between global temperature and atmospheric CO2 concentrations from 1980 through 2019, the scientists find CO2 changes can modestly impact temperatures. However, their analysis shows the relationship of temperature shifts and carbon dioxide concentrations throughout the twentieth and early twenty-first centuries “‘support[s] the hypothesis that the dominant direction is T → CO2,’ not CO2 → T,” as stated in the CO2 Coalition’s summary of the report.
The researchers determined the probability that temperature drives carbon dioxide changes is “about 4 to 5 orders of magnitude [greater], thus clearly supporting T → [CO2] as dominant direction.” The researchers determined the influence of carbon dioxide on temperatures is consistently smaller than the impact temperature changes have on carbon dioxide levels, with recent temperature changes leading CO2 changes by about six months to a year.
WARMER, WETTER WORLD OPTIMAL FOR LIFE
New research published in the peer-reviewed journal Astrobiology says the ideal planetary conditions for life are 5℃ warmer than today, with higher precipitation.
In the study, a team of astrobiologists and astrophysicists from research institutes and universities in Germany and the United States set out to make the search for life on planets outside our solar system more efficient by determining what planetary conditions are ideal for life. The scientists concluded, “Based on our experience from Earth, the highest biomass and biodiversity is present in tropical rainforests, and the least in cold polar regions. Thus, higher temperatures than currently existing on Earth seem to be more favorable.”
Among the atmospheric, ecological, and geological characteristics likely to create “superhabitable” planets, the scientists write,
[H]igher temperatures than currently existing on Earth seem to be more favorable. … One example is the early Carboniferous period, which was warmer and wetter (Raymond, 1985; Bardossy, 1994) on our planet than today, with so much biomass produced that we still harvest the organic deposits in the form of coal, oil, and natural gas from it. Thus, a slightly higher temperature, perhaps by 5°C—similar to that of the early Carboniferous time period—would provide more habitable conditions until some optimum is reached.
As pointed out earlier, a higher water content in the form of more moisture and more clouds would be beneficial in principle, with the rainforests on Earth being again a good example. A higher water content (absolute humidity) in the atmosphere would also provide more protection from UV irradiation.
Interestingly, as the Earth has warmed modestly, the U.N. IPCC reports with “high confidence” precipitation has increased over mid-latitude land areas of the Northern Hemisphere during the past 70 years, and it has “low confidence” about any negative trends globally.
As a result, contrary to the claim that a 1.5℃ or 2.0℃ rise in average global temperature would be a tipping point for a climate catastrophe, as is regularly asserted by climate alarmists and is assumed in the Paris climate agreement, a slightly warmer and wetter world would be a boon for life if these scientists are correct.