Analysis | How Extreme Weather Like Libya's Flooding is Linked to Climate Change

Scientists have predicted for decades that burning fossil fuels would push average temperatures ever higher and conjure dangerous extremes, such as those seen in the UK’s current tropical heat. A new branch of science, called extreme event attribution, that’s emerged in the past 15 years connects global warming to severe episodes of weather with a much greater level of specificity. Many individual heat spells, storms, floods, droughts and wildfires are now routinely tied to climate change. 1. What extreme weather is most tied to climate change? Heat waves are the weather events most directly linked to humanity’s greenhouse gas pollution. And heat, along with dryness and wind, fuels forest fires, which is why scientists have become so confident that climate change is making wildfires in the western US, Australia and elsewhere much worse. (The US fire season is two months longer than it was in the 1970s and 1980s.) Global warming is making tropical cyclones — also called hurricanes or typhoons — more intense, but not necessarily more frequent. Warmer water and moister air — two results of global warming — provide added fuel to tropical cyclones and other storms. 2. How certain is the link? The vast majority of extreme weather events reviewed by researchers since 2011 — 70% — were shown to be more likely to occur, or were made more severe, because of global warming. That’s according to a count maintained by CarbonBrief.org, a UK-based nonprofit that covers developments in climate science. 3. How is cold weather connected? Climate change has made winters shorter and blizzards and extreme cold snaps less likely. Earth’s poles are warming faster than elsewhere, with the North Pole heating up more than twice as fast as the rest of Earth for the last 30 years. This has caused a decrease in the contrast between the heat of the equator and the cold of the North Pole, and that has consequences. The record cold that crippled the Texas power grid in February 2021, for example, was the result of the polar vortex — a girdle of winds that typically keeps cold bottled in the Arctic — buckling and releasing cold air across much of the US. 4. What are other recent examples of extreme weather? At least 2,300 people were killed and 10,000 were missing in Libya in the immediate aftermath of a Mediterranean storm in mid-September. The June-July-August season was the warmest on record globally. The summer brought severe wildfires to Greece and neighboring countries, including the most devastating one on record in the European Union. A wildfire on the Hawaiian island Maui killed at least 115 people. In July, at least 100 people died in India in monsoon flooding, a month after a heat wave killed nearly 200 people. In May, Tropical Cyclone Mocha killed at least 145 people in Myanmar. Freddy, one of the longest lasting tropical cyclones on record, killed more than 1,000 people in southeast Africa in the early part of 2023. 5. Where is this headed? The world has warmed more than 1.1 degrees Celsius since the mid-19th century, according to the most authoritative source on the matter, the United Nations Intergovernmental Panel on Climate Change, or IPCC. At the current pace, that increase will reach 1.5 degrees — the level at which global warming becomes extra dangerous, in the view of climate scientists — as soon as the 2030s. From there, the intensity of extreme weather grows exponentially, doubling if global warming reaches 2 degrees and quadrupling at 3 degrees, the IPCC says. 6. What are the ramifications? More than 5 million people die each year globally because of excessive temperatures, and deaths tied to heat in particular are rising, according to a study in the Lancet Planetary Health. In addition to changing living conditions fundamentally, climate change is affecting many financial calculations, since huge parts of the global economy including agriculture, travel and insurance face risks tied to the weather. Insurers were hit by $89 billion of losses from disasters in 2020, the fifth-costliest year for the industry in data going back five decades, according to Swiss Re. The bulk of those costs were from natural catastrophes, including hurricanes Laura and Sally. It’s been estimated that climate change added $4 billion to the damage Typhoon Hagibis brought to Japan in October 2019, and that higher seas made Hurricane Sandy, which hit the US in 2012, $8 billion costlier. More stories like this are available on bloomberg.com ©2023 Bloomberg L.P.