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Yahoo
09-05-2025
- Climate
- Yahoo
Report: Climate change made April flooding, severe storms 9% more intense
Farm equipment is seen partially submerged on a flooded field in Ridgely, Tenn. on April 9, 2025. (Photo: Cassandra Stephenson) The effects of climate change made severe flooding that inundated West Tennessee and parts of the Central Mississippi River Valley in early April about 9% more intense, according to an analysis published Thursday by an international team of environmental researchers. From April 3 through April 6, thunderstorms and torrential downpours hovered over a broad swath of the Mississippi River Valley, leading to near-record breaking floods, widespread damage and at least 15 deaths. Those four days of rainfall are the heaviest recorded for the region in spring since 1950, according to the report published by World Weather Attribution, an international collaboration that analyzes the potential influence of climate change on extreme weather events. The study used observational data, historical records and climate models to examine how warming temperatures impact storm likelihood and intensity. Researchers also used nonprofit Climate Central's Ocean Climate Shift Index tool — based on observations and climate model data — to analyze sea surface temperatures in the Gulf of Mexico where much of the moisture fueling the storm originated, said Ben Clarke, a researcher at the Centre for Environmental Policy at Imperial College London. Researchers compared how this type of weather event has changed between today's climate — about 1.3 degrees Celsius hotter due to warming caused by use of fossil fuels and deforestation — compared to a cooler, pre-industrial climate (1850-1900). 'When we combine the evidence, we do find an overall increasing trend in such extremes,' Clarke said. 'Similar events have become, we estimate, about 40% more likely, or, equivalently, about 9% more intense.' Clarke noted that some climate models used in the study showed a more 'mixed picture' of the effects of warmer temperatures, meaning the study's results are 'likely a conservative estimate.' While the methods used in this study are peer-reviewed, the study itself was released in the immediate aftermath of the severe weather event and has not yet been peer-reviewed itself, Clarke said. Over four days in early April, eight states saw 'relentless amounts of rain' ranging from six to 12 inches, with some locations exceeding 16 inches, Climate Central Weather and Climate Engagement Specialist Shel Winkley said. The rain fell on soil that was already saturated from late-winter rain, particularly in the Ohio River Valley, he said. In Northwest Tennessee, the small town of Rives suffered severe flooding in February, only to flood again a few weeks later. Winkley said a ridge of high pressure over the Carolinas, Georgia and Florida blocked the low pressure system producing the storm from pushing forward, essentially stalling the storm front to dump rainfall over the already-saturated ground. Early warnings from the National Weather Service very likely saved lives, Bernadette Woods-Placky, Climate Central's chief meteorologist, said. In Obion County, Tennessee, more than 100 families evacuated their homes during the event. Nearby Dyer County issued a mandatory evacuation for residents of Bogota on April 7 in anticipation of additional flooding. Woods-Placky noted that layoffs and firings were beginning to roll out in National Weather Service offices across the U.S. as part of cost-cutting measures under the Trump administration around the time these floods were happening. 'This is an example of how critical these employees are and why recent workforce cuts risk undermining their ability to keep people safe and prepared,' she said. Winkley said post-storm analyses like this are vital for protecting public safety in future events. 'It helps us really understand, is this going to be a place that's livable in the future, and if it is, how do we make sure that it's livable and safe?' he said. The 96-hour rain event was the second-highest on record for the Obion, Forked Deer and Loosahatchie Rivers (all Mississippi River tributaries), according to the U.S. Army Corps of Engineers. Dyersburg, Tennessee — the county seat of Dyer County — is prone to flooding from the North Fork of the Forked Deer River. Early April's flooding marked the third-highest flood in the town's history, according to Mayor John Holden, who has held the position for 19 years. The worst flood in Dyersburg's history occurred in 2010, wiping out multiple homes and trailer parks. The second-highest flood record was set in 1937. Historical data indicates downpours like this are 'expected to occur, on average, about once a century in today's climate with 1.3 degrees Celsius of warming,' the report states. Before the storms rolled in, the National Weather Service's Weather Prediction Center warned the public of 'generational' rainfall totals. But the study's authors caution that further warming could increase the likelihood that these events will no longer be expected just once in a generation. 'If warming reaches 2.6 degrees Celsius (4.7 degrees Fahrenheit), which is expected by 2100 under current policies, four-day spells of rainfall are expected to become a further 7% more intense and twice as likely,' according to a study summary. 'This is a good moment to remember that we are a water planet, and a warmer atmosphere forces more evaporation, so our atmosphere in general has more water to come down whenever there's a trigger, wherever there's a trigger,' Woods-Placky said. 'So that's why we're seeing an overall increase in heavy rain events, even to places that may not be getting wetter. The distribution of how they're getting rain is coming in these heavier buckets.' Tennessee, Kentucky and Arkansas were hardest hit by the early April storms, and each state requested a major disaster declaration to access FEMA assistance. Damage estimates for public property and recovery in West and Middle Tennessee exceed $26 million, according to post-storm assessments. State and local officials believe this will meet the eligibility threshold for federal public aid. Tennessee has yet to receive a decision from the Trump administration. The administration approved a major disaster declaration for Kentucky on April 24. Arkansas Gov. Sarah Sanders requested a major disaster declaration to cover the April storms on May 3. Trump denied Sanders' earlier request for major disaster aid following storms and tornadoes in March. West Tennessee picks up pieces, awaits FEMA decision after severe storms The Tennessee Emergency Management Agency estimates around 300 homes and 14 businesses or nonprofits were severely damaged. West Tennessee mayors report hundreds of acres of flooded farmland. To illustrate the significance of the storm's 9% higher intensity that the study attributes to climate change, Imperial College London Centre for Environmental Policy Senior Climate Science Lecturer Friederike Otto refers to a separate study on Hurricane Helene. That study, published by the Grantham Institute of Climate Change and the Environment in 2024, estimated that a roughly 11% increase in wind speed due to climate change accounted for about 44% of the storm's damage in coastal Florida. Essentially, Otto said, the increase in intensity by 10% could nearly double the cost of damage. 'If that hits you (the region) once in a lifetime, I mean … that's one thing,' Otto said. 'But if that hits you twice, and it has the higher impact, that completely changes what … extreme weather can mean for a community.' SUPPORT: YOU MAKE OUR WORK POSSIBLE
Yahoo
04-02-2025
- Science
- Yahoo
Deaths of 30,000 fish off WA coast made more likely by climate change, research finds
Marine heatwaves linked to the deaths of 30,000 fish off the Western Australia coast were up to 100 times more likely to occur because of climate change, new research has found. Waters off WA have been affected by prolonged marine heatwaves since September. Regions off the north-west coast were hottest, with ocean temperatures 1.5C higher than average over a five-month period and sometimes 4C to 5C higher at the by the non-profit group Climate Central found climate change had made the marine heatwave 20 times more likely to occur – and the most affected period in November 100 times more likely. Heatwave conditions are triggered when an area is hotter than 90% of recorded temperatures for that time of year over at least five consecutive days. Dr Andrew Pershing, the chief program officer at Climate Central, which has adapted climate attribution methods for studying major weather events on land to the ocean, said the escalating heat seen off the coast of WA was 'not a normal event'. Related: Jo Haylen's swift exit after a series of own goals shows NSW Labor has learnt from past mistakes 'This is an event that is directly tied to burning fossil fuels,' he said. The group's Ocean Climate Shift Index drew on satellite data from organisations including the US National Oceanic and Atmospheric Administration, and applied 13 climate models, to isolate the effect of carbon pollution from human activities, Pershing said. Nearly 90% of marine heatwaves were now attributable to human-caused global heating and are expected to increase in frequency, intensity and duration as fossil fuel emissions continue to rise, previous studies have found. Marine heatwaves caused 'prolonged thermal stress' to marine life, which authorities say probably contributed to the mass fish kill observed at beaches along WA's Pilbara coast. Australia was 'on the frontline' of these effects, Pershing said. These events led to fish kills and coral bleaching and had widespread consequences for industries including fishing and tourism. A marine heatwave off the WA coast in 2010-11 damaged more than a third of seagrass meadows in Shark Bay. Dr Matt Rayson, an oceanographer at the University of Western Australia, who was not involved in the attribution study, said the heat that began building in the north in September had slowly crept down into the western side of Australia, with the ocean getting warmer at the surface. Autonomous ocean robots, deployed by the university, had also measured temperatures below the surface, finding unusual levels of heat. Rayson said 90% of the extra energy trapped by greenhouse gases was stored in the ocean, increasing the probability of ocean heatwaves. As well as effects on marine life, this additional energy could translate into severe weather events including tropical cyclones. WA's unusual marine heat was continuing to escalate. In January, ocean temperatures were consistently at least 1.6C hotter than average, according to Climate Central. Pershing said marine heatwaves weren't random. They were connected to climate change, he said, and becoming more intense and frequent as humans continued to pollute the atmosphere. 'Humans are affecting the planet in a lot of ways. We're used to thinking of how it affects us on land, but it's affecting everything on the planet, and the ocean is such a huge part of our planet.'
The Guardian
04-02-2025
- Science
- The Guardian
Deaths of 30,000 fish off WA coast made more likely by climate change, research finds
Marine heatwaves linked to the deaths of 30,000 fish off the Western Australia coast were up to 100 times more likely to occur because of climate change, new research has found. Waters off WA have been affected by prolonged marine heatwaves since September last year. Regions off the north-west coast were hottest, with ocean temperatures 1.5C higher than average over a five-month period and sometimes 4-5C higher at the surface. Sign up for Guardian Australia's breaking news email Analysis by the non-profit group Climate Central found climate change had made the marine heatwave 20 times more likely to occur – and the most impacted period in November 100 times more likely. Heatwave conditions are triggered when an area is hotter than 90% of recorded temperatures for that time of year over at least five consecutive days. Dr Andrew Pershing, the chief program officer at Climate Central, which has adapted climate attribution methods for studying major weather events on land to the ocean, said the escalating heat seen off the coast of WA was 'not a normal event'. 'This is an event that is directly tied to burning fossil fuels,' he said. The group's Ocean Climate Shift Index drew on satellite data from organisations like the US National Oceanic and Atmospheric Administration, and applied 13 climate models, to isolate the effect of carbon pollution from human activities, Pershing said. Nearly 90% of marine heatwaves were now attributable to human-caused global heating and are expected to increase in frequency, intensity and duration as fossil fuel emissions continue to rise, previous studies have found . Marine heatwaves caused 'prolonged thermal stress' to marine life, which authorities say likely contributed to the mass fish kill observed at beaches along WA's Pilbara coast. Australia was 'on the frontline' of these effects, Pershing said. These events led to fish kills and coral bleaching and had widespread consequences for industries like fishing and tourism. A marine heatwave off the WA coast in 2010-11 damaged more than a third of seagrass meadows in Shark Bay. Dr Matt Rayson, an oceanographer at the University of Western Australia, who was not involved in the attribution study, said the heat that began building in the north in September had slowly crept down into the western side of Australia, with the ocean getting warmer at the surface. Sign up to Afternoon Update Our Australian afternoon update breaks down the key stories of the day, telling you what's happening and why it matters after newsletter promotion Autonomous ocean robots, deployed by the university, had also measured temperatures below the surface, finding unusual levels of heat. Rayson said 90% of the extra energy trapped by greenhouse gases was stored in the ocean, increasing the probability of ocean heatwaves. As well as effects on marine life, this additional energy could translate into severe weather events like tropical cyclones. WA's unusual marine heat was continuing to escalate. In January, ocean temperatures were consistently at least 1.6C hotter than average, according to Climate Central. Pershing said marine heatwaves weren't random. They were connected to climate change, he said, and becoming more intense and frequent as humans continued to pollute the atmosphere. 'Humans are affecting the planet in a lot of ways. We're used to thinking of how it affects us on land, but it's affecting everything on the planet, and the ocean is such a huge part of our planet.'
