In February, two Swedish researchers published their study of plant megafossils in the Swedish Scandes and determined that Sweden was 2-3^oC warmer between 6,000-16,800 years ago.

While there has been warming in this region recently, the warming is within natural Holocene climate variability and poses no threat to these landscapes. Instead, warming may enhance biodiversity in this region.  The researchers wrote:

Global warming since more than 100 years is a meteorological reality, particularly amplified in northern and high-altitude regions already by the 1920s -1930s. This course of change is associated with large and predominantly progressive repercussions for biota, physical landscape and human society. However, the common and widespread perception of this development is that it represents a serious and imminent threat to man and planet Earth. This alarmistic and dystopic view is purported to the public and media by the prestigious International Council of Climate Change (IPCC) and its followers, which downgrade natural climate history and rely more on immature and unvalidated numerical models. The latter fail to reproduce recurrent natural climate changes in the long-term past (e.g., Karlén 1988; Hormes et al. 2001; Bengtsson et al. 2004) and to deliver reliable and useful climate projections for the future. In fact, modern warming is within natural Holocene climate variability (Vinós 2022).

Mt. Åreskutan Nunatak: An Arboreal “Roadmap” to the Paleobiogeograpy of the Swedish Scandes and a Possible Pointer Towards a Future Revival of a Richer and More Biodiverse Mountainscape, Kullman, L., & Öberg, L. (2024)

A megafossil is a fossil that is large enough to examine without the aid of a microscope. Plant megafossils are fossils of plants – such as leaves, stems, and roots – that have been preserved in sedimentary rocks.

The Holocene Epoch is a geologic time that covers the last 11,700 years of Earth’s history. Epochs are governed by a body of scientists in the form of the International Union of Geological Sciences (“IUGS”). The organisation uses rigorous criteria to decide when each chapter started and which characteristics defined it. The aim is to uphold common global standards for expressing the planet’s history.

The Holocene is unique among geologic epochs because varied means of correlating deposits and establishing chronologies are available including carbon-14 or radiocarbon dating, counting and measuring thicknesses in layers of lake sediments; effects of the Earth’s magnetic field; ash layers generated by volcanic eruptions and the measurement and analysis of tree rings.

Before the Holocene, was the Pleistocene Epoch during which a succession of glacial and interglacial climatic cycles occurred.  Some of the best-preserved traces of the boundary between the Pleistocene and Holocene are found in southern Scandinavia.

The Late Pleistocene, or Lateglacial, transition to the Holocene marks a critical period in Earth’s history, spanning from approximately 14,500 to 11,500 years ago. During this time, the Earth was transitioning from the last ice age to a warmer, more stable climate. The Lateglacial-Holocene period is characterised by significant environmental changes, including the retreat of glaciers, changes in vegetation and shifts in climate patterns.

Using radiocarbon dating to measure megafossils at the higher altitudes of Mt. Åreskutan in the Scandinavian Mountains, two Swedish researchers were able to establish that Sweden was 2-3^oC warmer in the Lateglacial and early Holocene periods than it is today.

Related: It’s all over for the Anthropocene, the official geologic period of human-caused climate change

Megafossil Carbon Dating Indicates Sweden Was 2-3°C Warmer Than Today During The Last Glacial

By Kenneth Richard published by NoTricksZone on 30 May 2024

“Modern warming is within natural Holocene climate variability” – Kullman and Öberg, 2024

From about 16,800 to 6,000 years ago warmth-dependent tree species grew 300-700 altitudinal metres higher than they do today on Mt. Åreskutan, Swedish Scandes.

Due to the well-known warmth threshold for boreal tree species and the lapse rate (0.6°C per 100m), recovering birch, spruce and pine megafossil remains at much higher elevations than today’s treeline altitudes affirms much warmer-than-today climates during the late last glacial and through the early Holocene, when carbon dioxide (CO₂) ranged from 190 to 255 parts per million (“ppm”).

“It is increasingly evident that common boreal tree species grew close to this summit in a climate, 2-3°C warmer than at present, during the Lateglacial and early Holocene periods 16,800-6,000 years ago.”

Mt. Åreskutan Nunatak: An Arboreal “Roadmap” to the Paleobiogeograpy of the Swedish Scandes and a Possible Pointer Towards a Future Revival of a Richer and More Biodiverse Mountainscape, Kullman, L., & Öberg, L. (2024)

The scientists point out that such early dating for warmer-than-today climates has been viewed as controversial, as it is assumed the Earth had not sufficiently warmed or deglaciated until about 11,000 years ago, near the official starting timeline for the Holocene. But the carbon dating of tree megafossils is regarded as a much more reliable data collection method than pollen analysis and terrestrial cosmogenic nuclide analysis, so these results are robust.

“Moreover, Mt. Åreskutan has been in the centre of a controversy concerning the date of deglaciation and late-glacial arboreal performance. Kullman (2000, 2002) presented robust megafossil data, showing unequivocal presence of mountain birch (Betula pubescens ssp. czerepanovii), spruce (Picea abies) and pine (Pinus sylvestris), as early as about 16,000 cal. a BP, close to the summit 300-400 m higher than present-day treelines.”

Mt. Åreskutan Nunatak: An Arboreal “Roadmap” to the Paleobiogeograpy of the Swedish Scandes and a Possible Pointer Towards a Future Revival of a Richer and More Biodiverse Mountainscape, Kullman, L., & Öberg, L. (2024)

While there has been warming in this region recently, the warming is “within natural Holocene climate variability” and poses no threat to these landscapes. Instead, warming may enhance biodiversity in this region.

The Intergovernmental Panel on Climate Change (“IPCC”) promulgates a contrasting “alarmist and dystopic” viewpoint of warming as a “serious and imminent threat to man and planet Earth” as they simultaneously “downgrade natural climate history and rely more on immature and unvalidated numerical models.”

For good measure, another new Scandinavian study (Salonen et al., 2024) indicates today’s temperatures in northern Finland are among the coldest of the last 8000 years (see “Present-day value” dashed line). Much of the Holocene – as well as nearly all of the last interglacial (LIG) – was 2 to 2.5°C warmer than present.