Bread and Circuses on Nostr: Below are a few excerpts from a very informative article about the rapidly rising ...
Below are a few excerpts from a very informative article about the rapidly rising levels of methane in our atmosphere. Why is it happening, and what does it mean?
Scientists aren't sure yet, but the possible implications are quite disturbing...
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Since 2006, the amount of heat-trapping methane in Earth’s atmosphere has been rising fast and, unlike the rise in carbon dioxide (CO₂), methane’s recent increase seems to be driven by biological emissions, not the burning of fossil fuels. This might just be ordinary variability, a result of natural climate cycles. Or it may signal that a great transition in Earth’s climate has begun.
Molecule for molecule, methane is a much more potent greenhouse gas than CO₂ but it lasts slightly less than a decade in the atmosphere compared with centuries for CO₂. Methane emissions threaten humanity’s ability to limit warming to relatively safe levels.
Even more troubling, the rate at which methane is increasing in the atmosphere has accelerated recently. Something like this has happened before: sudden surges in methane marked the transitions from cold ice ages to warm interglacial climates.
Methane is both a driver and a messenger of climate change. We don’t know why it is now rising so rapidly, but the pattern of growth since late 2006 resembles how methane behaved during great flips in Earth’s climate in the distant past.
In the past few million years, Earth’s climate has flipped repeatedly between long, cold glacial periods, with ice sheets covering northern Europe and Canada, and shorter warm interglacials. When each ice age ended, Earth’s surface warmed by as much as several degrees centigrade over a few millennia.
With each flip from a glacial to an interglacial climate there have been sudden, sharp rises in atmospheric methane, likely from expanding tropical wetlands. These great climate flips that ended each ice age are known as terminations.
Full terminations take several thousands of years to complete, but many include a creeping onset of warming, then a very abrupt phase of extremely rapid climate change that can take a century or less, followed by a longer, slower period during which the great ice caps finally melt. In the abrupt phase of the great change that brought about the modern climate, Greenland’s temperature rose by around 10°C within a few decades. During these abrupt phases, methane climbs very steeply indeed.
In glacial terminations, the entire climate system reorganises. In the past, this took Earth out of stable ice age climates and into warm interglacials. But we are already in a warm interglacial.
What comes next is hard to imagine: loss of sea ice in the Arctic in summer, thinning or partial collapse of the ice caps in Greenland and West Antarctica, reorganisation of the Atlantic’s ocean currents, and the poleward expansion of tropical weather circulation patterns. The consequences, both for the biosphere in general and food production in south and east Asia and parts of Africa in particular, would be very significant.
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FULL ARTICLE -- https://theconversation.com/rising-methane-could-be-a-sign-that-earths-climate-is-part-way-through-a-termination-level-transition-211211
#Science #Environment #Climate #ClimateChange
Scientists aren't sure yet, but the possible implications are quite disturbing...
____________________________
Since 2006, the amount of heat-trapping methane in Earth’s atmosphere has been rising fast and, unlike the rise in carbon dioxide (CO₂), methane’s recent increase seems to be driven by biological emissions, not the burning of fossil fuels. This might just be ordinary variability, a result of natural climate cycles. Or it may signal that a great transition in Earth’s climate has begun.
Molecule for molecule, methane is a much more potent greenhouse gas than CO₂ but it lasts slightly less than a decade in the atmosphere compared with centuries for CO₂. Methane emissions threaten humanity’s ability to limit warming to relatively safe levels.
Even more troubling, the rate at which methane is increasing in the atmosphere has accelerated recently. Something like this has happened before: sudden surges in methane marked the transitions from cold ice ages to warm interglacial climates.
Methane is both a driver and a messenger of climate change. We don’t know why it is now rising so rapidly, but the pattern of growth since late 2006 resembles how methane behaved during great flips in Earth’s climate in the distant past.
In the past few million years, Earth’s climate has flipped repeatedly between long, cold glacial periods, with ice sheets covering northern Europe and Canada, and shorter warm interglacials. When each ice age ended, Earth’s surface warmed by as much as several degrees centigrade over a few millennia.
With each flip from a glacial to an interglacial climate there have been sudden, sharp rises in atmospheric methane, likely from expanding tropical wetlands. These great climate flips that ended each ice age are known as terminations.
Full terminations take several thousands of years to complete, but many include a creeping onset of warming, then a very abrupt phase of extremely rapid climate change that can take a century or less, followed by a longer, slower period during which the great ice caps finally melt. In the abrupt phase of the great change that brought about the modern climate, Greenland’s temperature rose by around 10°C within a few decades. During these abrupt phases, methane climbs very steeply indeed.
In glacial terminations, the entire climate system reorganises. In the past, this took Earth out of stable ice age climates and into warm interglacials. But we are already in a warm interglacial.
What comes next is hard to imagine: loss of sea ice in the Arctic in summer, thinning or partial collapse of the ice caps in Greenland and West Antarctica, reorganisation of the Atlantic’s ocean currents, and the poleward expansion of tropical weather circulation patterns. The consequences, both for the biosphere in general and food production in south and east Asia and parts of Africa in particular, would be very significant.
____________________________
FULL ARTICLE -- https://theconversation.com/rising-methane-could-be-a-sign-that-earths-climate-is-part-way-through-a-termination-level-transition-211211
#Science #Environment #Climate #ClimateChange