Climate Impact Report – 12/21

Quick Facts


Tennessee counties to begin Preliminary Damage Assessments after deadly tornado outbreak


dry conditions during those last few months of 2020 amplified the severe drought of 2021 in Utah

4th time

this month, extremely unseasonable warmth will dominate the nation’s weather

Key Facts Of The Day 12/21

Storms and Flooding

  • A tornado is possible in Florida as strong storms bring in cold fronts.

  • Winter storms will sweep across California, bringing snow and rain to holiday travel.

    • Winter storm warnings are in effect for the Sierra Nevada from 4 p.m. Wednesday to 4 p.m. Sunday.

    • The Sierra and areas above 6,500 feet will see periods of significant snowfall starting late Tuesday and continuing through the weekend.

  • 18 Tennessee counties to begin Preliminary Damage Assessments after deadly tornado outbreak.

    • The assessments will determine the state’s eligibility for additional federal help to support recovery efforts from the deadly tornado outbreak on Dec. 10 and 11.

  • Nearly six months after a historic storm on June 26 dumped 6 inches of rain on Detroit in a matter of hours, some cultural institutions are still dealing with the aftermath.

    • The Wright museum is one of at least five Detroit cultural institutions that sustained significant flooding after the storm, causing extensive damage.

    • Flooding at the Detroit Symphony Orchestra’s Max M. and Marjorie S. Fisher Music Center on Woodward, the Michigan Science Center and Fisher Theatre also required serious restoration work.

    • The Motown Museum had some damage.

    • Cultural institutions in particular face unique challenges because some are in historic buildings or were built with issues that may make them more prone to flooding.

  • For the next few months, the northern hemisphere will experience its coldest temperatures.

    • Winter brings big snowstorms, most notably in the New York and New England regions, with powerful storms coming up the Atlantic coast known as “Nor’easters.”

    • With more than half of the state’s residents living in the greater New York City area, sea level rise puts people, resources, and the state’s economy at risk.

    • The state is planning over $4 billion in sea level rise solutions, which include raising roads, fixing drainage, and building seawalls.


  • As of Friday, there are currently 8 large active wildfires that have burned 40,165 acres across OK, and TX. As of Friday, 57,465 wildfires have burned 7,687,881 acres across the country.

  • KNP Complex Fire in California is fully contained months after wildfire sparked.

    • The wildfire scorched more than 88,000 acres after it was sparked by lightning in September.

    • The fire forced the evacuation of many communities, closed public lands, and ultimately killed approximately 3% to 5% of the world’s population of mature giant sequoias.

  • The influx of robins in central Oregon may be caused by wildfires’ habitat disruption in late winter.

  • After years of delays, CalFire says updated and expanded wildfire hazard maps are on their way.

    • The California Department of Forestry and Fire Protection last updated its fire hazard severity zone maps in 2007, well before recent record-breaking megafires swept across California.

    • Local governments use CalFire’s hazard zones as a guide post in deciding where new homes and businesses should be approved or rejected.

    • Homeowners who live inside high risk zones have to disclose that risk when they decide to sell. The number of homes in those high-risk areas has grown in the last decade.

    • Past mapping focused on geographic hazards such as forests and canyons where fire spreads, now climate hazards are front and center.

Extreme Heat

  • Extremely dry conditions during those last few months of 2020 amplified the severe drought of 2021 in Utah.

    • By March, Gov. Spencer Cox declared a state of emergency in Utah, putting out the plea for all water users to cut back and cut back severely.

    • For the first time in the history of the Colorado River Basin water sharing agreement, the bureau announced mandatory water delivery reductions to lower basin states such as Nevada and Arizona due to dwindling lake levels.

    • The protracted drought had Utah leaders revisiting a list of 300 potential sites for new dams to capture runoff.

    • Insufferably high temperatures in the summer led to two heat-related deaths in Utah and spurred warnings about the effect of urban heat islands in areas like Salt Lake City.

    • July broke or tied heat records in the state and already dry lawns turned more brown.

    • According to the National Oceanic and Atmospheric Administration, November was the second-driest on record for the West and Southwest regions and in Utah, Nevada and Colorado.

  • For the fourth time this month, extremely unseasonable warmth will dominate the nation’s weather.

    • Most of the Lower 48 will be looking at a spike in temperatures over the coming days that could send highs some 30 degrees or more above normal.

    • In many spots, the weather on Christmas Eve and Christmas Day will be more reminiscent of a typical Easter.

    • Heat extremes have outpaced cold records at a rate greater than 2 to 1 this year.

  • As temperatures rise, crossing into the US will become even more deadly.

    • Summer temperatures in the region routinely top 100 degrees and water sources are few and far between.

    • Hundreds of migrants die every year in the area, often succumbing to the effects of heat and dehydration.

    • Migrant deaths are concentrated in areas where evaporative water loss and dehydration are more likely.

New Reports And Data

  • A December 2021 study found that the accelerating melting of the Himalayan glaciers threatens the water supply of millions of people in Asia.

  • A December 2021 study found that forest restoration treatments can reduce future fire severity and benefit populations of California spotted owls.

  • A December 2021 study found that glacial erosion likely caused atmospheric oxygen levels to dip over the past 800,000 years.


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