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Scientists have been observing the extreme weather events that occurred around the world this summer and have seen many connections between heat waves, floods, droughts and climate change.
However, the scale of some of these events, and the extent to which they have disrupted previous records, suggests that the climate is no longer changing in a gradual, predictable way.
Deadly heat waves and other severe weather have renewed attention to the tipping point—that is, a major shift to critical ecosystems (such as Greenland’s ice sheet or the Amazon rainforest) could cause huge and irreversible effects on the planet’s climate balance. Variety.
Owen Gaffney, an analyst at the Stockholm Resilience Center, a research organization, said: “The tipping point is a large-scale change that may happen suddenly and may not be reversed.”
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Hashem Akbari, an environmental engineer at Concordia University, said the solution must include stopping climate change. 5:23
He co-authored one 2019 articles In the “Nature” magazine, it lists nine global critical points that scientists are increasingly paying attention to. A classic example is the ice sheets in parts of Antarctica and Greenland. Studies have shown that these ice layers will not gradually shrink as the climate warms, but may reach a path of no return, leading to rapid and irreversible ice disappearance—and the corresponding global sea level rise.
According to the report, in Greenland, models indicate that “the ice sheet may be doomed to disappear when it warms by 1.5 degrees Celsius, which may happen in 2030”.
In Canada, the trend is worrying. This summer, different parts of British Columbia broke temperature records during the June heat wave. In particular, the town of Lytton set a record of 49.6 degrees Celsius, the hottest ever recorded in Canada—a significant increase of 5.2 degrees Celsius from the previous record. Litton in 1941.
“The analogy used by scientists in the past is that when you make the climate warmer, it’s like loading a pair of dice. So now when you roll the dice, you get more six points than before,” Simon Downer said. Professor at the University of British Columbia, researching climate science and public policy.
“But what we saw this summer was not a 6, but a 7 or 8, which was impossible with the old dice.”
A sort of learn A group of international scientists studied how many heat waves on the west coast can be attributed to man-made climate change, and the results show that one explanation for high temperatures may be “non-linear interactions in the climate.”
The theory believes that because the interactions in the climate system are not fully understood, the current amount of climate change is leading to an increase in extreme high temperatures that exceed expectations, rather than a gradual increase in extreme temperatures.
This raises questions about what cities and communities need to do to adapt to the increasingly uncertain future climate.
The tipping point may have been reached
An international team of climate scientists Warn now There is “increasing evidence that we are approaching or have already crossed the critical point related to key parts of the Earth system.” In a paper published in the journal Biological Sciences on July 28, researchers pointed out that western Antarctica and the Greenland ice sheet, warm water coral reefs, and Amazon rainforest are climate systems that may be close to or have reached a tipping point.
The paper tracked 31 key climate variables, such as global emissions and loss of tree cover, and found that 18 of them are historical records. These include three important greenhouse gases: carbon dioxide, methane and nitrous oxide, which set new records in atmospheric concentrations in 2020 and 2021.
Considering the effects we see during global warming of approximately 1.25 degrees Celsius, “combined with many enhanced feedback loops and potential tipping points, large-scale climate action is urgently needed,” the paper said.
Paul Ritchie, a mathematician and climate scientist at the University of Exeter in the United Kingdom, studied where these critical points are and how far we can surpass some of them while still recovering. Rich said that certain changes, such as the disappearance of ice sheets, have a relatively long time scale and have occurred over many centuries.
“But there are these other factors… these may happen in a shorter time frame, maybe years or decades,” he said.
“So, once we cross these specific thresholds, we may know immediately because the Amazon rainforest has suddenly disappeared or the monsoon suddenly ceases to operate.”
Both events will have devastating consequences. Millions of people rely on monsoons for agriculture, and the disappearance of the Amazon River may release more carbon and accelerate global warming.
Adaptation is still possible, but Canada has not
Canada announced a plan to develop a national adaptation strategy in December 2020. But experts warn that the country is not ready for our current climate and needs to act quickly to deal with the future.
“The reality is that we should assume that we will not encounter that [Paris Agreement] 2 degrees Celsius target,” said Gordon McBeane, a professor at the University of West London in Ontario, speaking of a global agreement to reduce carbon emissions to prevent the worst effects of climate change.
McBean is the lead investigator On a report Established community resilience to climate change for the federal government earlier this year.
His report found that although many cities have formulated high-level plans to address climate change, other cities still lack detailed implementation strategies or funds.
The report stated: “Most of Canada’s actions to build community resilience were unplanned and were carried out in the recovery process after extreme losses.”
McBean said that as the average temperature rises linearly, the number of extreme weather events will increase dramatically. “Adaptation strategies must consider not only future weather forecasts, but also future greenhouse gas emissions forecasts, and the possibility that other parts of the world will not be able to achieve their emission reduction targets.
He said the recent thermal domes and tornadoes are examples of the types of events that will occur more frequently in the future.
As the climate will continue to change in the coming years and new information about the danger of tipping points that may lead to unforeseen extreme weather emerges, adaptation becomes more urgent.
McBein said that there is now enough information to start planning for that uncertain future and make the community more resilient.
“It’s not that we failed. It’s that this is what we need to do,” he said.
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