A tipping point describes how a small change can lead to large, dramatic and often times unanticipated changes in a system. If the climate reaches a tipping point it will cause abrupt changes in the climate. Abrupt climate change refers to where a large and widespread shift in the climate occurs within a short period of time, possibly only a decade. These abrupt changes will lead to dangerous and possibly irreversible changes to the earth’s climate. Is the climate reaching tipping points?
We can use the past as a guide to determine if we are approaching tipping points. Fifty five million years ago there was a global warming trend similar to what we are witnessing today. Then there was a sudden release of massive amounts of carbon into the atmosphere – this carbon was most likely methane released from the ocean floor and from permafrost. This release triggered an abrupt increase in global temperature which rose 9 to 160 F leading to mass extinction of plants/animals and the Arctic Ocean became ice free. This climate change lasted about 120,000 years and it took another 40,000 years for the planet to return to cooler temperatures.
Today as the global temperature continues to increase - 1.470 F in the past three decades – scientists have detected methane rising from the floor of the Arctic Ocean. This year more Arctic sea ice has melted than any other time in recorded history. It is estimated that the Arctic Ocean will be ice free within the next few decades. Some experts even predict the Arctic Ocean could be ice free within five years.
Tipping points can also occur when the climate reaches a state such that strong amplifying feedbacks are activated by only moderate additional warming. An amplified feedback is occurring today in the Arctic. As I stated in a previous posting dark surfaces – ice free ocean water – absorbs heat from the sun while light surfaces – ice covered ocean water – reflects the sun’s radiation back into outer space. As more and more of the Arctic Ocean becomes ice free this accelerates the warming of not only the ocean water but also the air mass over the Arctic. This warm air mass triggers the melting of the Greenland glaciers which exposes dark land surfaces and thus more amplification.
It is not known how close the climate is to reaching tipping points. Some experts believe the Arctic has already reached a tipping point. Nevertheless, if we continue “business as usual” with our use of fossil fuels it will happen! We can’t wait any longer because it will take the climate 100s to 1000s of years to remove the excess carbon from the atmosphere. In other words if we converted to carbon neutral energy sources today, all the extreme weather events that are occurring will continue for 100s of years. Waiting any longer will at the very least increase the number and intensity of extreme weather events.
If we fail to act and the climate goes through a series of tipping points, we will leave a climate crisis for future generations to deal with that they had no part in creating. This is morally wrong!