Since 1980, the U.S. has experienced an average of six extreme weather events costing over $1 billion each. Last year there were 16 such events including Hurricanes Harvey, Irma and Maria but also lesser known occurrences like a southeast crop freeze, three Midwest tornados and a drought in the northern states. All told, the 16 events cost the country over $300 million, a new record expense.
Last May, Colorado experienced a spring hail storm costing $1.4 billion, a record level of loss. It is estimated that over 200,000 insurance claims were filed for damaged homes and vehicles. In a noteworthy and alarming trend, seven of the 10 most expensive hailstorms in Colorado history have occurred in the last 10 years.
California’s devastating wildfires also made the list of most expensive extreme weather events. From the Oregon border in the north to the southern border with Mexico, 2017 California wildfires were the worst in history of the state. According to Cal Fire (The California Department of Forestry and Fire Protection), the five largest wild fires in California history have occurred in the past 10 years. Ten of the most destructive (in terms of property damage and expense to replace property) fires in California history have taken place in the last 20 years – three in the last ten years.
Both the largest and the most destructive fires occurred last year. The largest ever, the Thomas fire in Southern California, started in December and burned for a full month. Nearly 300,000 acres were consumed by the blaze. With little remaining vegetation to absorb precipitation, subsequent heavy rains caused mudslides in the area responsible for over 40 deaths and substantial property damage.
The most destructive fire, the Sonoma County Tubbs fire, burned over 5,643 structures, double the next most damaging fire in California history. The 36,807 acres burned by the Tubbs isn’t large in relative terms but the blaze was also responsible for 22 deaths. Of the top ten destructive fires, six were caused by electrical issues, power lines or generally human related causes and four are still under investigation. In high-risk areas, especially Northern California, utilities will have to follow specific safety measures to abate utility related fires, according to a map released last week, by the California Public Utilities Commission.
Last year was marked by a wet spring, perfect for new vegetation that served as kindling during a hot, dry summer. A lack of winter precipitation in some areas has produced conditions conducive to fire with no relief in sight for California, or as the case in Santa Barbara County, fatal mudslides if precipitation is heavy enough. Contaminated air and water as a result of wildfire airborne ash and muddy rainfall runoff continue to be problematic for residents.
Climate Change in the United States
California wildfires, Colorado hailstorms, snow in southern states and drought in northern states might all be considered anomalies without taking into account historical context. With multi-year comparisons, climate change is considered a root cause. Climate change is a statistically significant change in weather patterns sustained over an extended time period. Most scientists studying the issue have concluded that many of these changes are occurring because of the human impact of carbon dioxide emissions through the use of fossil fuels. Experts are careful not to attribute isolated extreme weather events like a cold snap or unusual precipitation to climate change but the increased and consistent incidence of these events and permanent changes are being closely tracked as signalling a changing climate.
As an example, the fact that 2017 was the third warmest year ever recorded on earth in the last 140 years could be attributed to chance. However, when the National Oceanic and Atmospheric Association (NOAA) recites that, “The six warmest years on record for the planet have all occurred since 2010,” the trend signals climate change.
Other significant findings from NOAA’s 2017 climate report include the third highest sea temperature on record, the second smallest Arctic ice formations in history, and the smallest amount of ice in Antarctica since tracking started in 1979.
Effect on Colorado
Noting the beetle killed forests in the Colorado mountains shouldn’t lead one to any conclusions about climate change, but rather beg the question to whether there might be cause and effect. When coupled with knowledge that the state has warmed by two degrees over the past few decades, climate change should be considered.
Unfortunately, this winter is an example of another trend – lower than average snowpack for the past twenty years and quicker melt affecting two of the state’s most important industries, agriculture and tourism. The recent cold wave throughout southern states and Mexico brought snow to some places that haven’t seen snow in decades. By mid-December, cities in Louisiana, Mississippi and Georgia received more snowfall than Denver. The lack of snow leads to increased wildfire danger, shorter ski and snowboard seasons in a competitive tourism market, and less water available for crops.
Former Colorado state legislator, Dan Grossman, has more recently turned his attention to environmental protection. As the National Director of State Programs for Environmental Defense Fund’s Oil and Gas Program, Grossman helps states protect their natural environment in an era of energy development. He warns of the effects, “Climate change in the West means longer, more persistent drought, more severe weather events such as floods, and less hospitable conditions for agriculture and recreation.” Grossman continued, “Unchecked, climate change will wreak havoc on our economy and the environment.” Grossman specializes in air quality policies and regulation, an increasingly important issue in Colorado.
Understanding Climate Change
NOAA has developed a section of their web site to disseminate information about climate change: www.climate.gov. One aspect of the site features a Global Climate Dashboard providing graphs showing trends for Global Average Temperature, Carbon Dioxide in the atmosphere, and Spring Snow Cover. A series of maps can also be searched – Colorado’s shows a steady increase in mean temperature since record-keeping in 1895. A series of teacher’s resources is also available.