Scientists find that deadly Hurricane Helene, wildfires in the Amazon, extreme monsoon downpours in India, heat waves during the Summer Olympics and other dangerous and devastating weather events in 2024 are all becoming more likely and more likely to occur due to climate change Destructive.
Climate scientists quantified this link by running thousands of simulations in climate models, some including and some excluding the effects of human-caused atmospheric climate pollution. They also examined past and present weather data to see how the chances of such events changing in a hot world.
This approach is called attribution science and is a relatively new branch of climate science. It has led scientists to conclude that human-caused climate change has made many recent extreme weather events far more damaging, deadly and costly than they would otherwise have been.
Climate change increases destructive potential of hurricanes Helen and Milton
Hurricane Milton, which formed in the Gulf of Mexico in early October, provides an example of how climate change is exacerbating extreme weather. Due to warm water temperatures, the storm quickly intensified from a tropical storm to Category 5. Climate Central scientists estimate that climate change is 400 to 800 times more likely to cause abnormal increases in sea surface temperatures.
Hurricane Helen made landfall near Perry, Florida on September 26, 2024, with Category 4 winds of 140 mph. The storm killed 247 people and left hundreds more missing, making it the fourth deadliest hurricane in the United States since at least 1963. Probably hundreds of people were underestimated.
Preliminary estimates of economic damage from the storm were as high as $47 billion.
On Wednesday, attribution science organization World Weather Attribution released an analysis of how climate change affected Hurricane Helene. Their main findings:
- Today, the region is roughly 2.5 times more likely to experience a hurricane as powerful as Hurricane Helen: In a pre-industrial climate, hurricanes were expected to occur on average every 130 years, but now the chance of occurring annually is 1 in 53 .
- Hurricane Helene's winds along the Florida coast were about 13 miles per hour, or an 11 percent increase in wind speed due to climate change.
- Climate change increased Hurricane Helene's rainfall by about 10%. Due to climate change, rainfall levels that cause catastrophic flooding in the Appalachian Mountains have shifted from a 115-year return to a 70-year return today.
- Climate change makes it 200 to 500 times more likely that high seawater temperatures will fuel Hurricane Helene.
“Our research shows once again that if humans continue to burn fossil fuels and subsequently warm the planet, hurricanes will become more severe,” said Frederic O, senior lecturer in climate science at Imperial College London and head of world weather attribution. To express the release in the news. “Americans don’t have to worry about hurricanes more powerful than Helen – we have all the knowledge and technology we need to reduce demand and replace oil, natural gas and coal with renewable energy.”
For every 5% increase in hurricane wind strength, the destructive power of a hurricane increases by approximately 50%, as the damage caused by a hurricane increases exponentially with intensity. As a result, the World Weather Attribution Group found that Helen's winds increased by 11%, which may have more than doubled the destructiveness of Helen's winds.
And it's hurricanes that drive storm surges, so while there's no direct assessment of storm surges in the group's report, it can be inferred that climate change made Helen's destructive surges more severe (in addition to separate long-term increases in storm surge and storm surge). outside).
Another quick analysis by scientists at Lawrence Berkeley National Laboratory estimates that climate change increased rainfall by more than 50 percent during Hurricane Helene in parts of Georgia and the Carolinas, where global warming has increased the risk of heavy rainfall. The likelihood increases 20 times.
The costs of climate change are extremely high
Recent research shows that climate-worsening extreme weather events are taking a huge toll on life, health and finances around the world.
Home insurance costs have more than doubled in the U.S. over the past two decades, and many insurers are pulling out of states like Florida and California that are particularly vulnerable to climate-related extreme weather like hurricanes and wildfires. The Federal Emergency Management Agency (FEMA) is running out of money to help communities recover from extreme weather disasters.
The faster the world can rein in climate-warming pollution and achieve net-zero emissions, the less devastating future extreme weather events will be. But people also need to prepare for the types of extreme weather that are most common in their areas, knowing that they will continue to get worse until climate change stops.
Without global warming, extreme heat would be 'virtually impossible'
Worsening heat waves are the most direct consequence of pumping climate-warming pollution into the atmosphere. By trapping more heat on the Earth's surface, pollution raises average temperatures around the world and makes extreme heat waves hotter and more frequent. Heat waves are the deadliest type of extreme weather in the United States. Heat-related deaths tend to be significantly underestimated because coroners often attribute deaths to direct causes such as heart attacks, and not necessarily to triggering factors such as heat stress.
July 22, 2024, is the hottest day on earth. Nearly half of the planet experienced dangerously high temperatures that day, and climate change has made such high temperatures at least three times more likely, according to an analysis by Climate Central. The organization also estimates that more than 2 billion people, or a quarter of the global population, face at least 30 days of dangerously high temperatures between June and August, with climate change at least three times more likely.
The 2024 Summer Olympics in Paris were also affected by an extreme heat wave across the Mediterranean region. Event organizers were forced to renovate environmentally friendly athletes' dormitories and equip them with 2,500 air conditioners. An analysis of heat waves by World Weather Attribution estimates that such extreme heat would be nearly impossible to occur without human-caused global warming. But in today's hotter world, the region is expected to experience similar extreme heat waves about once every decade.
Mexico and a wide area stretching from Israel and Palestine in the west to the Philippines in the east also experienced extreme heat waves in the spring and early summer. During this period, Mexico reported more than 100 heat-related deaths and thousands of cases of heatstroke. In Gaza, extreme heat has worsened living conditions for 1.7 million displaced people.
World Weather Attribution estimates that climate change will increase heat wave temperatures in Mexico by approximately 1.5°C or 2.7°F, making them 35 to 200 times more likely to occur. Scientists found that this event would not have been possible in the Philippines without human-caused climate change. Climate change is also making high temperatures in West Asia five times more likely.
Drought likelihood increases 10 to 30 times in Amazon region
In arid areas of the planet, global warming will exacerbate droughts and wildfires because rising temperatures increase evaporation, drying out soil and vegetation.
These conditions are emerging in the Amazon rainforest this year, with a recent study in the journal Nature reporting that the annual number of days of hot, dry and extreme fire weather has tripled. Another study published earlier this year in the journal Nature found that by 2050, these conditions could put 10% to 47% of rainforests under enough stress to trigger tipping points and lead to forest degradation or tree scarcity. savanna.
Wildfires in Brazil's rainforest and southern Pantanal have burned more than 32 million acres this year, releasing a total of 150 million tons of carbon dioxide. That’s about one-third of Brazil’s annual fossil fuel climate pollution. The World Weather Attribution Group estimates that climate change makes droughts in the Amazon 10 to 30 times more likely. As a result, Amazon wildfires in 2024 are about 40% more destructive and four to five times more likely to occur.
Italy's two largest islands, Sicily and Sardinia, have also been suffering from extreme drought since May due to very little rainfall and high temperatures. The two islands have been under water rationing since February, but their reservoirs are nearly empty. Sicily declared a state of emergency in May.
The World Weather Attribution Group concluded that these intensely hot and dry conditions are highly unlikely to occur without human-induced climate change, and that similar conditions will become more frequent and severe in a warming world.
More intense, deadly rainstorms
French military engineer and physicist Nicolas Léonard Sadi Carnot discovered the relationship between temperature and vapor pressure 200 years ago. His findings were subsequently used to estimate that for every 1°C (1.8°F) increase in temperature, the amount of water vapor in the Earth's atmosphere would increase by about 7%. As a result, more water in the air falls as precipitation during storms and can cause flooding. When it rains, it's more likely to pour down.
In September, Central Europe saw the most intense rainfall in the region to date, directly affecting nearly 2 million people. Scientists from the World Weather Attribution Organization conservatively estimate that the event is twice as likely and 7% more intense due to global warming. If global warming reaches 2°C, such events are expected to be 5% more intense than today and 50% more likely to occur.
In northern Kerala, India, an extreme monsoon downpour triggered massive landslides on July 30, killing hundreds of people. It was the third-heaviest single-day rainfall ever recorded in the area. World Weather Attribution estimates that global warming has increased the intensity of this event by 10%, and that if global warming reaches 2°C, the intensity of similar events will increase by another 4%.
In late April and early May, more than 16 inches of rain fell in Rio Grande do Sul, Brazil's southernmost state, causing flooding in more than 90 percent of the state. These unprecedented floods displaced 600,000 people, injured more than 150,000 people, and killed more than 169 people. World Weather Attribution estimates that climate change has doubled the likelihood and increased the intensity of such events by 6-9%. If global warming reaches 2°C, such extreme flooding will be twice as likely and 4% more intense than now.
Jeff Masters contributed to this article.
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