Published on Jan 22, 2017
An abrupt climate change occurs when the climate system is forced to transition to a new climate state at a rate that is determined by the climate system energy-balance, and which is more rapid than the rate of change of the external forcing. About the book: https://www.amazon.com/gp/product/B00…
Past events include the end of the Carboniferous Rainforest Collapse, Younger Dryas, Dansgaard-Oeschger events, Heinrich events and possibly also the Paleocene-Eocene thermal maximum. The term is also used within the context of global warming to describe sudden climate change that is detectable over the time-scale of a human lifetime. One proposed reason for the observed abrupt climate change is that feedback loops within the climate system both enhance small perturbations and cause a variety of stable states.
Timescales of events described as ‘abrupt’ may vary dramatically. Changes recorded in the climate of Greenland at the end of the Younger Dryas, as measured by ice-cores, imply a sudden warming of +10 °C (+18 °F) within a timescale of a few years. Other abrupt changes are the +4 °C (+7.2 °F) on Greenland 11,270 years ago or the abrupt +6 °C (11 °F) warming 22,000 years ago on Antarctica. By contrast, the Paleocene-Eocene thermal maximum may have initiated anywhere between a few decades and several thousand years. Finally, Earth Systems models project that under ongoing greenhouse gas emissions as early as 2047, the Earth’s near surface temperature could depart from the range of variability in the last 150 years, affecting over 3 billion people and most places of great species diversity on Earth.
The IPCC states that global warming “could lead to some effects that are abrupt or irreversible”.
In an article in Science, Richard Alley et al. said “it is conceivable that human forcing of climate change is increasing the probability of large, abrupt events. Were such an event to recur, the economic and ecological impacts could be large and potentially serious.”
A 2013 report from the U.S. National Research Council called for attention to the abrupt impacts of climate change, stating that even steady, gradual change in the physical climate system can have abrupt impacts elsewhere—in human infrastructure and ecosystems for example—if critical thresholds are crossed. The report emphasizes the need for an early warning system that could help society better anticipate sudden changes and emerging impacts.
Abrupt climate change has likely been the cause of wide ranging and severe effects:
Mass extinctions in the past, most notably the Permian-Triassic Extinction event (often referred to as the great dying) and the Carboniferous Rainforest Collapse, have been suggested as a consequence of abrupt climate change.
Loss of biodiversity. Without interference from abrupt climate change and other extinction events the biodiversity of this planet would continue to grow.
Rapid Ocean acidification, which can harm marine life (such as corals).