Researchers are documenting the damaging impact of worsening drought and wildfires over the past three years
In a recently published study, Prof. Michael Mann and his colleagues investigated the effects of climate change on worsening complex conditions of heat and drought. Their discovery paves the way for better prediction of these intertwined weather phenomena. This can allow scientists and policy makers a more comprehensive understanding, thereby improving prevention and planning strategies regarding severe weather events.
"We wanted to see how the latest climate models used in the most recent assessment reports of the Intergovernmental Panel on Climate Change relate to cases of heat waves and droughts that have caused some of the most severe forest fires we have seen in the recent past," says Mann.
"We also wanted to better understand how often these events occurred, their typical duration and intensity to improve prediction and also approaches to reduce their future harm to human life."
The researchers are documenting the damaging impact of worsening drought and fires over the past three years.
"Two notable events," says Mann, "were the fires in California in 2020 and the wave of fires in Australia in 1919-20, which lasted almost a whole year and was named the Black Summer. Such events are called "complex drought and heat wave" (CDHW), which is a situation in which the region has both prolonged hot temperatures and a lack of water.
These conditions can occur together and mutually exacerbate their effects, the researchers say, and can potentially lead to heat-related illnesses and deaths, water shortages for drinking and agriculture, reduced crop yields, increased fire risk and ecological distress. They also note that climate change caused by human activity can contribute to the frequency and severity of these events.
The researchers compared two contrasting socio-economic paths: the most severe scenario in which society fails to reduce the effects of climate change caused by human activity, and a moderate scenario in which certain conservation measures are taken and an effort is made to act on them.
In the most severe scenario, they found that by the end of the 21st century, about 20% of the world's land areas are expected to experience about two CDHW events per year. These events can last around 25 days and their severity will be quadrupled.
"For comparison, the frequency of CDHW during the reference period averaged about 1.2 events per year, lasting less than ten days, and their severity is much less," Mann says.
The researchers emphasize the strong threat posed by more frequent and powerful CDHW events in the coming decades and the dependence that exists between the emission path that will be chosen and the severity of these events.
As climate change continues to occur, addressing the escalating risks associated with CDHW events becomes critical. This study adds to the understanding of projected changes in CDHW events and highlights the need for proactive measures, including emissions reductions and adaptation strategies, to build resilience and protect vulnerable areas from the impact of complex drought and heat wave events.
"Our findings provide an important scientific context for the record heat and fires we are witnessing right now in the United States," says Mann. "They emphasize that we must stop using fossil fuels as quickly as possible to prevent the worsening of this dangerous combination of heat and drought."
More of the topic in Hayadan: