Natural Variability: The Northern Hemisphere Cooled And Warmed By 1°C In Decades ~1500 Years Ago

By: - Climate DepotJuly 27, 2020 4:16 PM

Natural Variability: The Northern Hemisphere Cooled And Warmed By 1°C In Decades ~1500 Years Ago

It is claimed Earth’s surface has warmed by 1°C in the last 140 years – which is a supposedly rapid climate change. But a new study suggests the Northern Hemisphere surface naturally cooled by 1°C in 8 or 9 years, then warmed up again by 1°C within decades during the Late Antique Little Ice Age.

Scientists have determined there were “catastrophic volcanic eruptions that took place in 536, 540 and 547 A.D.” Sulphate aerosols consequently scattered the Sun’s radiance, dramatically cooling the Earth’s surface for decades. This global cooling period, referred to as the Late Antique Little Ice Age (LALIA), resulted in crop failures, famines, disease epidemics, and societal unrest. After the cooling event, Earth’s climate naturally returned to its previous warmth.

Using proxy records from 20 Northern Hemisphere (NH) locations, Peregrine, 2020specifies that it cooled by about 1°C in less than a decade in the 530s and 540s A.D. By the 570s, however, the NH climate had warmed back up again (by 1°C).

These rapid climate changes easily exceed the pace of modern temperature changes (about 1°C total warming since 1880) assumed to be of anthropogenic origin.

Image Source: Peregrine, 2020

Extensive volcanism is also said to explain the Little Ice Age (LIA) centennial-scale global cooling (McGregor et al., 2015).

Image Source: McGregor et al., 2015

Modern warmth can thus be interpreted as a return to the climate “normal” – much like the abrupt return to pre-LALIA temperatures after that global cooling period ended.

Since the return to “normal” temperature after the LALIA cooling was necessarily a natural warming, the 1900s-to-present warming could also be interpreted as a natural event. After all, this is the null hypothesis – and at no time has it been falsified using real-world scientific evidence.

Image Source: Chill by Peter Taylor