US’ third-warmest year on record came with floods, fire, drought, and hurricanes.
A changing climate, however, is implicit in the very first paragraph. 2017, it notes, is the 21st consecutive year with above-average temperatures in the US. It ranks third on the all-time heat list, coming in at 1.45 degrees Celsius (2.6 degrees Fahrenheit) above the 20th century average. The US’ five warmest years on record, NOAA notes, have all occurred after 2006. It was also the third consecutive year in a row that every single state experienced above-average temperatures. For five states, 2017 was the warmest year on record. All of which indicates a major trend in the US’ temperatures.
Although the temperatures didn’t set a new record, the cost of weather events in 2017 did. The US saw 16 weather and climate disasters that each cost more than $1 billion, with total costs rising above $300 billion. That’s nearly $100 billion more than the next closest year (2005), which featured Hurricanes Katrina, Wilma, and Rita. Last year’s trifecta featured Hurricanes Harvey, Maria, and Irma at total costs of $125 billion, $90 billion, and $50 billion, respectively. All three placed in the top five costliest disasters of all time in the US. These disasters also killed 362 people directly.
These storms helped ensure that 2017 was the fifth consecutive year with above-average precipitation (Michigan set a record with a meter of rain). But the rain wasn’t evenly distributed. The Rockies and Great Plains near the Canadian border were well below average and slipped into drought. The impact of that drought on agriculture cost more than $1 billion, adding to the year’s disaster totals.
Heavy rains eased the West Coast’s drought. Unfortunately, they also encouraged heavy growth of plants in the spring, which set the stage for wildfires after the region’s normally dry summer. Those incidents also made NOAA’s list of billion-dollar-plus disasters. The rest were largely an assortment of extreme rain and tornado events scattered throughout the Great Plains and Midwest.
The report drives home two key aspects of climate change. One is that while climate change may be a factor in extreme weather events, boosting either their probability or severity, it won’t be the only factor, and there will always be other factors. These range from random chance to more proximal causes, like specific weather patterns that promote drought or floods.
The second is that the warming climate is an average. Over a large geographic region like the US, that average may include extreme events with opposing impacts. Thus, it’s possible that an “average” looking year in the US can feature heavy rains ending a drought in one region even as others slip into drought. And until the planet is much warmer, there’s always the chance for a warm year in the US to feature record low temperatures, as this January is demonstrating.
In honor of the 50th anniversary of the beginning of the Apollo Program, Ars Technica brings you an in depth look at the Apollo missions through the eyes of the participants.