The recent heat wave in the northwest United States and Canada was “virtually impossible” without man-made global warming. This is written by an international group of scientists in the first rapid analysis released Wednesday. In the current climate, they estimate the probability that such an event will occur at that location once every thousand years. But they add that it is difficult to quantify exactly, because it was a rare and disproportionate event. The analysis was carried out at the initiative of the World Weather Attribution, an organization that investigates extreme weather events and the role of climate change in them.
Earth is now on average 1.2°C warmer than it was in the pre-industrial era. If the climate warms to an average of 2°C, this heat wave will occur every 5 to 10 years. At the rate at which humans are now releasing additional greenhouse gases into the atmosphere, this point will be reached sometime in the 1940s.
Read also The most important village in Canada destroyed by wildfires during the heat wave
The heat wave peaked on June 29, when the temperature reached 49.6 degrees Celsius in the Canadian town of Lytton. This is about five degrees higher than the country’s previous temperature record. The heat caused a drought that led to widespread wildfires in the affected area. Lytton was almost completely reduced to ashes. At least 721 people died as a result of the heat and subsequent fires.
A very different future
The researchers focused their analysis on the Seattle-Portland-Vancouver area, which has more than 9 million residents.
They warn that rapid climate warming exists An area not shown on the map – In an unknown area. With “significant effects on health, well-being and life”. Humans will have to adapt much more quickly in order to prepare society for a “completely different future.” For example, by making heating plans and building homes and offices that are better adapted to the heat. The ever-increasing greenhouse gas emissions must also be reversed and brought to zero as quickly as possible.
Climate scientists are quite surprised that the heat wave has reached such high temperatures. That such a thing was possible was not in their expectations. In their analysis, they looked at whether they had overlooked a factor in the climate system that could explain the unusually high temperatures. Based on current data, they don’t think that’s the case. It appears that, even in the current climate, it is an event with a very low probability. In other words: luck. They write it themselves as a statistical equivalent of Really bad luckReal bad luck.
A version of this article also appeared in NRC Handelsblad on July 8, 2021