By Stacy Morford, The conversation
Disasters have continued to occur throughout 2021, from the destruction of Hurricane Ida across Louisiana and the northeast to devastating wildfires in the west and devastating storms, tornadoes and flooding. Nearly half of the United States was in a drought, and extreme temperature spikes disrupted power supplies just when people needed cooling or heating the most.
In total, the costliest weather and climate disasters of the year in the United States estimated $ 145 billion in damage and killed at least 688 people, the National Oceanic and Atmospheric Administration announced on January 10, 2022.
It was the third most expensive year on record.
2021 was also one of the hottest years in the world and 4th hottest year in the United States in 127 years of record keeping. Not all weather events is caused by global warming, but rising temperatures affect the climate in a way that amplify heat waves and droughts and can overload storms. Much of this temperature rise is caused by greenhouse gases that build up in the atmosphere from the burning of fossil fuels.
As disasters unfolded, scientists explained the influence of climate change. Here’s what they said about some of the costliest disasters of 2021.
Extreme precipitation in the east, drought in the west
One feature that stood out during the disasters of 2021 was a sharp division of precipitation in the United States: as much of the west was in the grip of severe drought or worse, with dry vegetation fueling the fires. , much of the eastern half of the country was soaked.
Extreme downpours in August triggered flash floods in Tennessee that washed away homes and vehicles and killed 20 people. Days later, the remnants of Hurricane Ida swept across the country and struck New York with record precipitation which overwhelmed metro stations and basement apartments, killing dozens more.
Across the country, the drought damage from the west was much more difficult to calculate. The extreme drought close a key hydropower plant in California for five months, damaged farms and ranches and led to the first federal water use restrictions for the Colorado River that the levels have fallen in the important reservoirs.
“A higher temperature increases evaporation from the Earth’s surface, drying out vegetation and soils, which can fuel forest fires. It also increases the ability of the atmosphere to retain moisture at a rate of about 7% per degree Celsius as the planet warms. With more moisture evaporating, global precipitation is should increase, but this increase is not uniform, ”Wu wrote.
As the planet warms, wetlands are likely to become wetter and drier areas drier, she said.
N ° 1: Hurricane Ida
hurricane Ida, which exploded from a weak hurricane to a Category 4 storm over warm waters in the Gulf of Mexico, was the costliest disaster of 2021, with damage in Louisiana and then in the Northeast estimated at around $ 75 billion.
University of Miami Oceanographer Nick shay explained how the storm passed over a large pool of warm water in the Gulf of Mexico that had detached from the loop current. The warmth of this hot pool, stretching down to about 480 feet, fueled his strength.
Hurricanes are powered by hot water, so warming of surface temperatures will have an effect on them. Climate models suggest that the Atlantic hurricane precipitation and intensity will increase, but there won’t necessarily be more thunderstorms.
# 2: the Texas freeze
In February, an arctic explosion sent ice, snow and freezing temperatures to the center of the country. In Texas, the cold breath quickly became a human disaster. Cold weather Texas power grid submerged, freezer components in natural gas plants and the slowdown in the supply of natural gas. About 69% of the state has lost power, and NOAA has counted 226 deaths. State officials awarded 246 deaths to the storm.
This cold snap was the second costliest U.S. disaster of 2021, with costs estimated at around $ 24 billion.
Although it may seem counterintuitive, rapidly warming temperatures in the arctic can trigger this kind of southerly dip in the jet stream, a strong band of winds at the boundary between colder and warmer air. Research by atmospheric scientists Matthew Barlow at the University of Massachusetts Lowell and Judah Cohen at MIT show how it can happen because changes in the Arctic are followed by changes in the stratospheric polar vortex, which are followed by cold waves in North America and Asia.
“Our research reinforces two crucial lessons from climate change: First, change doesn’t have to happen in your garden to have a big effect on you. Second, the unintended consequences can be quite serious, ”they wrote.
# 3: Devastating forest fires
Heat and drought in the West have contributed to more multibillion-dollar disasters. On December 30, when Colorado was normally blanketed in snow, a forest fire whipped by strong winds ravaged neighborhoods in Abnormally dry Boulder County. Almost 1,000 homes and several businesses were destroyed in a matter of hours.
The blaze followed devastating fires in California over the summer. In total, damage from the 2021 western fires was estimated at $ 10.6 billion.
As rising global temperatures dry up vegetation, forest managers face increasing risks and costs of wildfires. Fighting huge forest fires, such as the Dixie and Caldor fires in California that destroyed much of Greenville and Grizzly Apartments by 2021, deplete funds for fire prevention efforts, such as forest thinning and prescribed burns, University of California forest and fire experts Susan kocher and Ryan tompkins wrote.
“To manage fires in a time of climate change, where drier, warmer weather creates ideal conditions for burning, experts believe that the area treated for fuel reduction needs to increase by at least one. magnitude,” they said.
What about tornadoes?
Tornadoes, like the deadly epidemic that created another multibillion-dollar disaster in Kentucky and neighboring states in early December, have not been clearly linked to global warming, but climate models can still give insight, as professor of meteorology at Central Michigan University John allen Explain.
“There are certainly signs pointing to a more stormy future,” Allen said, “but how this manifests for tornadoes is an open area of research.”
Editor’s Note: This story is a summary of articles from the Archives of The Conversation. It has been updated with the NOAA Disaster Map.