Alaska's 'Age of Glaciers' will end this century
Much of the world's ice may soon disappear for good, triggering a global climate regime that humans have never experienced as a species.
The long-running era of glaciers — meaning the Pleistocene ice age that has periodically covered North America and Alaska with vast sheets during the past 2.5 million years — may be ebbing to its final close, according to a new analysis out of Poland.
The inexorable rise in greenhouse gases, and the warming that will come before the end of the century as a result, will likely suspend the “glaciation/interglaciation cycles” that have controlled the planet’s climate for millennia, writes scientistWojciech Budzianowski of Wrocław University of Technology in theInternational Journal of Global Warming.
“A new analysis of climate change data and the effects of rising levels of the greenhouse gas carbon dioxides suggests that we are at the end of the period in Earth's history during which icy glaciers form,” according to this story.
“The study further suggests that the effects of rising CO2 levels is delayed as long as 50 years but global average temperature might be as much as (9 degrees Fahrenheit) higher than it is today by the year 2100.”
One of Budzianowski’s major findings is that the Earth’s “thermal response” to rising levels of greenhouse gases can lag behind for many decades, says the paper’s abstract.
Budzianowski points out that atmospheric concentration of carbon dioxide has been increasing at a rate of 2 parts per million by volume per year — rising from about 220 parts per million by volume before the Industrial Revolution to about 390 parts per million by volume today.
That’s the highest CO2 concentrations seen on Earth in about 15 million years.
“It is likely that the increased content of carbon dioxide in the atmosphere is one of the major causes of the differences between mean annual temperatures in the late 1800s and those existing today, i.e., about (1.4 degrees F)," Budzianowski explains here.
This sudden rise in greenhouse gas concentrations will become a much more powerful climate “trigger” than the factors that used to swing Earth back and forth between widespread glaciation and hemispheric meltbacks. Those factors -- changes in how much solar energy gets reflected back into space, or fluctuations in the amount of heat and light coming from the Sun -- will be sidelined by the energy trapping abilities of greenhouse gases.
“The self-oscillatory behaviour of past climates that see the periodic build-up and melting of large masses of glaciers in the Arctic and Antarctic regions is no longer valid,” Budzianowski explains in this story.
“As such, there will be no build up of ice cover and glaciers in the future, so the cycle is broken.”
Contact Doug O'Harra at doug(at)alaskadispatch.com.
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