Challenges in the Detection and Attribution of Northern Hemisphere Surface Temperature Trends Since 1850

Abstract

Since 2007, the Intergovernmental Panel on Climate Change (IPCC) has heavily
relied on the comparison between global climate model hindcasts and global surface temperature
(ST) estimates for concluding that post-1950s global warming is mostly human-caused.
In Connolly et al. (2021), we cautioned that this approach to the detection and attribution of
climate change was highly dependent on the choice of Total Solar Irradiance (TSI) and ST
datasets.We compiled 16 TSI and 5 ST datasets and found by altering the choice of TSI or ST,
one could (prematurely) conclude anything from the warming being “mostly human-caused”
to “mostly natural”. Richardson and Benestad (2022) suggested our analysis was “erroneous”
and “flawed” because we did not use a multilinear regression. They argued that applying a
multilinear regression to one of the 5 ST series re-affirmed the IPCC’s attribution statement.
They also objected that many of the published TSI datasets were out-of-date. However, here
we show that applying multilinear regression analysis to an expanded and updated dataset of
27 TSI series, the original conclusions of Connolly et al. (2021) are confirmed for all 5 ST
datasets. Therefore, it is still unclear whether the observed warming is mostly human-caused,
mostly natural or some combination of both.

A jelenkori felmelegedés lehetséges hatótényezőiről • On the Potential Drivers of Current Global Warming

“…Egy másik -az IPCC WG1 AR6-tal egy időben megjelent, tizennégy ország huszonhárom kutatójának tollából származó -tanulmány szerint azonban a magabiztos IPCC-állítás megalapozatlan és elsietett volt (Connolly et al, 2021a). Összefoglaljuk Ronan Connolly és szerzőtársai (2021a) fő megállapításait, a tanulmány nemzetközi fogadtatását (beleértve a Magyar Tudományos Akadémiáét is), valamint a Connolly és szerzőtársai köre által a kritikák hatására készített és nemrég megjelent két újabb, még alaposabb elemzés eredményeit (Connolly et al, 2023;Soon et al, 2023). E két cikk megerősíti és részletgazdag módon kiegészíti Connolly és szerzőtársai (2021a) következtetéseit, miszerint a jelenkori felmelegedés oka továbbra is nyitott kérdés.…”

Uncertainty of Climate Models and Policy Implications: A European Perspective

“…Further, some authors argue that GHGs receives too high a weight in climate models, while natural factors receive too little attention, see e.g. Gervais (2016), Ollila (2017), Lightfoot and Mamer (2017), Stefani (2021), Kim et al (2022), Omrani et al (2022), Connolly et al (2023). Smirnov and Zhilyaev (2021) state that the greenhouse eect of CO 2 is heavily overestimated in climate models since those models do not take into account the thermodynamics of the atmosphere and radiation eld.…”

Terrestrial Temperature, Sea Levels and Ice Area Links with Solar Activity and Solar Orbital Motion

“…Bottom plot-The variations of the temperature (black curve) versus versus the averaged sunspot numbers (yellow curve). [80,81]. However, if the sum of TSI calculated for the whole year, the deposited solar radiation has a wide variation in magnitudes imposed by the smaller SIM effects remaining though nearly a constant wide strip over the time of two centuries.…”

“…The fact that the ocean level correlates with the spring-summer TSI magnitudes, which is not considered when producing the solar forcing for the terrestrial temperature models [3] is likely to create the discrepancy between the solar heating function used in the current temperature models. Besides any increases of the terrestrial temperature caused by the temperature measurements in urban conditions where Natural Science temperature by default is higher [80,81]., there is additional solar heating caused by solar orbital motion induced by the gravitation of large planets.…”