North Atlantic climate variability consistent with Atlantic Multidecadal Oscillation

Marie Nicolle et al. Climate variability in the subarctic area for the last 2 millennia. Climate of the Past, 14, 101–116, 2018  https://doi.org/10.5194/cp-14-101-2018

To put recent climate change in perspective, it is necessary to extend the instrumental climate records with proxy data from paleoclimate archives. Arctic climate variability for the last 2 millennia has been investigated using statistical and signal analyses from three regionally averaged records from the North Atlantic, Siberia and Alaska based on many types of proxy data archived in the Arctic 2k database v1.1.1. In the North Atlantic and Alaska, the major climatic trend is characterized by long-term cooling interrupted by recent warming that started at the beginning of the 19th century. This cooling is visible in the Siberian region at two sites, warming at the others. The cooling of the Little Ice Age (LIA) was identified from the individual series, but it is characterized by wide-range spatial and temporal expression of climate variability, in contrary to the Medieval Climate Anomaly. The LIA started at the earliest by around AD 1200 and ended at the latest in the middle of the 20th century. The widespread temporal coverage of the LIA did not show regional consistency or particular spatial distribution and did not show a relationship with archive or proxy type either. A focus on the last 2 centuries shows a recent warming characterized by a well-marked warming trend parallel with increasing greenhouse gas emissions. It also shows a multidecadal variability likely due to natural processes acting on the internal climate system on a regional scale. A ∼ 16–30-year cycle is found in Alaska and seems to be linked to the Pacific Decadal Oscillation, whereas ∼ 20–30- and ∼ 50– 90-year periodicities characterize the North Atlantic climate variability, likely in relation with the Atlantic Multidecadal Oscillation. These regional features are probably linked to the sea ice cover fluctuations through ice–temperature positive feedback.

Australia’s Great Barrier Reef is Doing Just Fine, Thank You

“The truth, of course, is that the Great Barrier Reef (GBR) isn’t dying at all. (As we’ve written here and here)

In fact it’s doing just fine and the gagged professor – Peter Ridd of James Cook University – has plenty of solid scientific evidence to prove it.” click here

The Roots of Global Warming Religion

Black History Month: The Story of Sgt. William Carney

“The president told the story of Sgt. William Carney, the first African-American Medal of Honor recipient. Carney, a former slave, was recognized for rushing to save the American flag from touching the ground, despite taking multiple gunshot wounds.” click here

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Satellite-Based Temperatures of the Global Lower Atmosphere

Australia’s university campuses are hostile to free speech

“IPA research has found a worsening state of free speech on Australia’s university campuses. The IPA’s Free Speech on Campus Audit 2017 found 34 of Australia’s 42 universities are hostile to free speech on campus through their actions and policies.” click here

500-Year Cycle Signals in Solar Activity

Lihua Ma, Zhiqiang Yin, Yanben Han. Quasi 500-Year Cycle Signals in Solar Activity, Earth Science Research; Vol. 7, No. 1; 2018

Direct observations of solar activity are available for the past four century, so some proxies reflecting solar activity such as 14C, 10Be and geomagnetic variations are used to reconstruct solar activity in the past. In this present paper, the authors use rectified wavelet power transform and time-averaged wavelet power spectrum to investigate long-term fluctuations of the reconstructed solar activity series. The results show an obvious quasi 500-year cycle exists in the past solar activity. Three reconstructed solar activity series from 14C variations confirm the periodic signals.