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In the summer of 2020 Siberian temperatures reached 38 °C, the highest ever recorded temperature within the Arctic Circle. During the same year, Arctic wildfires released 35% more CO2 than in 2019. The permafrost region contains a massive frozen store of ancient organic carbon, in total about twice the amount of carbon in the Earth’s Read the full article…
Northern permafrost soils represent the largest terrestrial organic carbon pool on Earth. A study the northern circumpolar permafrost zones reveals that landscapes susceptible to abrupt thawing with the release of significant quantities of carbon dioxide and methane cover 20% of the northern permafrost region and store up to half its soil organic carbon.
A new study has concluded that methane emissions from the U.S. oil and natural gas supply chain in 2015 amounted to about 2.3% of gross U.S. gas production. Emissions of this magnitude significantly increase the GHG footprint of natural gas power generation and erode the carbon advantage of natural gas over coal.
In contrast to West Antarctica where several large glaciers have been losing ice for decades, East Antarctica glaciers have exhibited little evidence of ice loss but NASA’s latest detailed maps of East Antarctica ice velocity and elevation show that a number of glaciers have begun to lose ice over the past decade.
A seminal book by Milankovitch in 1941 proposed that the sequence of ice ages that has characterized long term changes in the Earth’s climate over the past hundreds of thousands of years was due to changes in the amount of solar radiation reaching the Earth as a result of small variations in the Earth’s orientation and orbit with respect to the sun. Since then research has shown that Milankovitch cycles by themselves do not determine the timing of glacial and interglacial cycles and that we still lack a unified mechanism that links changes in Earth’s orbit to ice ages.
Evidence from Antarctic ice cores have revealed a close correlation between surface temperature and atmospheric carbon dioxide concentration for the past 800,000 years (excluding the immediate present.) A recent analysis of Antarctic blue ice has found that the close correlation between temperature CO2 extends to 1.5 million years ago during the time when the glacial/interglacial period was 40,000 years.
June 5, 2017
Approximately 800,000 years ago something changed in the Earth’s climate system that led to the climate then following a series of approximately 100,000 year cycles. Small, predictable changes in the Earth’s orbit about the Sun act as triggers for the glacial and interglacial periods, but other factors such as ice sheet volume, CO2 concentration, and biological feedback mechanisms are also involved.
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A recent study of ice cores from Antarctica provides a climate record for the past 800,000 years. The analysis reveals that atmospheric carbon dioxide was strongly correlated with Antarctic temperature throughout eight glacial cycles.
It is known that orbital forcing is involved in glacial/deglacial cycles but is insufficient by itself to explain the glacial/deglacial cycles. This study argues that a biological feedback mechanism kicks in when a threshold is reached and together with orbital forcing results in the sustained and rapidly increasing CO2 and surface temperature of a deglaciation.
The last deglaciation was characterized by increases in surface temperatures of 10-15 °C punctuated by millennial-scale warming/cooling periods, pulses of increasing atmospheric carbon dioxide and asynchronously increasing methane. A geospatial-temporal variance analysis reveals a global warming trend correlating with rising CO2 on which is superimposed second trend millennial-scale regional warming/cooling periods associated with variation in the strength of the Atlantic overturning current.
A recent study, published in Nature, reports on how anonymized data from three quarter of a million global smart phones was used to detect and map physical inactivity around the world. The study is an outstanding example of the type of scientific analyses that is possible using human beings as sensors.