{"id":427588,"date":"2026-02-23T18:38:08","date_gmt":"2026-02-23T17:38:08","guid":{"rendered":"https:\/\/climatescience.press\/?p=427588"},"modified":"2026-02-23T20:48:28","modified_gmt":"2026-02-23T19:48:28","slug":"scafetta-climate-models-fail-to-reproduce-the-medieval-warm-period-undermining-claims-of-unprecedented-man-made-warming","status":"publish","type":"post","link":"https:\/\/climatescience.press\/?p=427588","title":{"rendered":"Scafetta: Climate Models Fail to Reproduce the Medieval Warm Period, Undermining Claims of Unprecedented Man-Made Warming"},"content":{"rendered":"\n
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Modern climate models are used to support the claim that recent warming is unprecedented and largely man-made. This claim is based on the assumption that the models can accurately reproduce Earth’s past climate behavior. But they don\u00b4t.<\/p>\n\n\n\n

A closer look at Nicola Scafetta’s new study<\/a> shows that climate models repeatedly fail to reproduce known warm periods of the past, including the Medieval Warm Period (MWP) between about 900 and 1300 AD.<\/p>\n\n\n\n

Scafetta highlights the Medieval Warm Period (MWP, ~900\u20131300 CE) as a prime example of model shortcomings. <\/p>\n\n\n\n

Proxy-based reconstructions (e.g., from earlier studies like Lamb 1965, and more recent ones such as Moberg et al. 2005, Ljungqvist 2010, Christiansen and Ljungqvist 2012) show a pronounced warm phase in the Northern Hemisphere, often estimated as warmer than the first half of the 20th century in some records, followed by the Little Ice Age (LIA, ~1300\u20131850 CE). These form part of quasi-millennial oscillations (e.g., the Eddy cycle).<\/p>\n\n\n\n

However, CMIP GCMs (especially those in CMIP6 used for IPCC AR6) produce relatively flat or minimally varying temperatures during this medieval interval. They do not capture the significant warming.<\/p>\n\n\n\n

Nicola Scafetta is an Italian physicist and researcher (affiliated with institutions like the University of Naples and previously with Duke University\/NASA-related labs) known for his work on climate variability, solar influences, and critiques of mainstream climate models.<\/p>\n\n\n\n

His research frequently discusses the Medieval Warm Period (MWP, roughly 800\u20131350 CE), a period of relative warmth documented in various paleoclimate records, particularly in the Northern Hemisphere (e.g., Europe, North Atlantic regions). Scafetta argues that the MWP (along with earlier periods like the Roman Warm Period) reflects significant natural climate variability, often linked to a quasi-millennial oscillation in climate records.<\/p>\n\n\n\n

Key points from his publications:<\/p>\n\n\n\n