Weather Whiplash
By Hunter Cutting
After decades of carbon pollution and deforestation, record-breaking temperatures and extreme weather are now part of the new normal. From the flooding in the Carolinas to the wildfires in California, the landscape of our lives has changed.
We see the signs of warming everywhere: in temperature readings, satellite measurements, disappearing sea ice, vanishing glaciers, melting ice sheets, changing seasons, migrating species, and the accelerating rise of the oceans as the seas warm and expand. At last count, there are more than 26,500 such signals.
We are now also living with dramatic changes in extreme weather and its impacts. Extreme downpours, storm surges, heat waves, droughts and wildfires have all been significantly amplified by climate change, in some cases dramatically. These changes were expected — a small shift in Earth’s climate produces a substantial shift in extreme weather.
Areas experiencing the worst heat events around the world are now 10 times larger. In the United States, new record-high temperatures regularly outnumber new record-lows by two to one, and there has been an unprecedented spike in hot nights during these heat waves, eliminating the overnight reprieve badly needed by children, the elderly and the ill. The spring-like temperatures warming much of the East Coast right now, in the middle of winter, is a classic signal of climate change.
Between rains, warming temperatures are drying out the landscape and amplifying droughts when they strike, such as the recent California drought, which was the worst dry-spell to hit the state in over 1,200 years.
Global warming also intensifies the conditions that fuel wildfires. The fingerprint of climate change has been found in the measurable increase in western lands struck by wildfires, such as last year’s Soberanes wildfire, which was the costliest wildfire fight in the U.S. history at well over $250 million.
Along our coasts warming is driving sea level rise that, in turn, is stretching out the reach of storm surge. 24 percent of the surge damage inflicted by Superstorm Sandy was due to elevated sea levels that lengthened the reach of the storm. A small vertical rise in sea level translates into a long horizontal reach of surge in low-lying areas.
The warming atmosphere also is holding more moisture and dumping more water when it rains. So not surprisingly, deluges have increased worldwide. And flooding risk in the United States has jumped upward. Over the past century, the U.S. has witnessed a 20 percent increase in the amount of precipitation falling during the heaviest downpours.
The growth in extreme rainfall has in turn increased the threat of flooding in the U.S. The recent string of historic floods, from Houston to Louisiana to the Carolinas and now California, is consistent with the direction of climate change on our warming planet. When it rains it pours.
Climate change is often the straw that breaks the camel’s back. Our nation’s infrastructure, such as dams and bridges, was built for the climate of the past, not the rapidly changing climate of the present. Our infrastructure was designed and built to withstand the extremes we knew, not the new extremes that confront us now. These new and more intense extremes can overwhelm systems and infrastructures, driving them past the point of collapse.
Climate disruption is turning extreme events into weather disasters. Going forward means managing the risks we can now no longer avoid, while at the same time moving to avoid the catastrophic risks that we could never manage.
