By Jim Steele

Attached are 3 graphs revealing the evolving reconstructions of trends in global temperatures. Climate researchers are now producing a greater abundance of proxies for more accurate pre-industrial temperatures. Michael Mann’s 1999 “hockey stick” graph is the outlier, having eliminated the Medieval Warm Period and then producing a rapid uptick in temperatures since the Little Ice Age that ended in ~1850. Based on that graph, Mann and the IPCC suggested rising CO2 has increased temperatures higher than ever before in the past thousands of years.

However, as science has progressed, subsequent studies using the increasing availability of more reliable temperature proxy records, revealed that current temperatures are not significantly different from the high temperatures during Medieval Warm Period ~1000-years ago and the Roman Warm Period ~2000-years ago.

Ljungqvist (2010) concluded that temperatures in “substantial parts of the Roman Warm Period…, and the Medieval Warm Period… have equaled or exceeded AD 1961–1990.”

Buntgen (2020) concluded, “Peak warming in the 280s, 990s and 1020s, when volcanic forcing was low, was comparable to modern conditions until 2010 CE.”

The growing evidence that Medieval Warm Period temperatures were very similar to today has undermined the value of Michael Mann’s graph and climate crisis alarmist narratives who fear monger recent temperatures are unprecedented and deadly.

Thus as expected, alarmists deny the most recent scientific data to argue either the Medieval Warm Period didn’t exist, or that it was not global. But that is hypocritical. Mann’s hockey stick was not global but based on northern hemisphere proxy data.

Still, in keeping with the alarmists attempt to suppress good climate science, climate researcher Dr. David Deming testified before the 2006 senate Hearing on Climate Change and the Media that a major climate researcher and IPCC member invested in the Mann hockey stick graph, privately circulated an email amongst friends pleading, “We have to get rid of the Medieval Warm Period.” Deming also testified that a biased NPR journalist wanted to interview him regards his research but only if Deming agreed to blame human emissions on warming.

To satisfy the current crop of climate editors, all three graphs shown here have spliced modern temperature constructions, based on instrumental temperatures, onto their research that had been focused just on past proxy temperatures. Mann (1999) splices on modern instrumental temperatures in red, Ljungqvist (2010) with a dashed black line, and Buntgen (2020) with a solid dark blue line. But such splicing creates the classic blunder of ignorantly comparing apples to oranges.

Proxy temperature constructions in all the graphs have been dominated by tree ring data, most sensitive to summertime temperatures. Climate scientists seek out the oldest trees in groves that are away from streams and lakes that could influence local temperatures, as well as groves that have not been affected by human lumbering or other activities. But splicing instrumental data onto tree ring data is really very, very bad science, verging on a complete scam!

Trees growing in groves experience far lower temperatures than thermometers subjected to tree-less urbanized landscapes. This is easily demonstrated by infrared photography of the greater Atlanta Georgia area. Neighborhoods with abundant trees have much lower temperatures. Globally, urbanized areas dominate th location of most official thermometers. As seen, Atlanta’s urbanized areas experiences temperatures 6°C (10°F) to 12°C (22°F) higher temperatures than neighborhoods with abundant trees. Likewise modern urbanized instrumental temperatures misleadingly suggest todays temperatures are far higher than temperatures determined from what past tree groves have experience.

Sadly, alarmist scientists are comparing apples to oranges to manufacture unprecedented warming.

There is no global warming climate crisis!