Helene - 327

As I write this, 200 people have died from Hurricane Helene. The giant vapor storm* made landfall in Florida's Big Bend as a rapidly intensifying Category 4 storm, capable of "catastrophic damage." While Helene brought a storm surge of 15 feet to Florida, it continued through Georgia, the Carolinas, Tennessee, and Virginia, resulting in flash floods and record-breaking rainfall. Damage is estimated at 160 billion.

North Carolina's infrastructure failed under the sheer volume of rainfall. In some areas, floodwaters submerged roads and washed away bridges, cutting off access to critical services. Thousands of downed trees blocked roads and snapped power lines. Emergency responders struggled to rescue stranded residents, the ones still able to contact them.

In anticipation of the storm, President Biden approved emergency declarations for several states, enabling the federal government to mobilize FEMA, provide disaster relief, and deploy resources such as emergency power, food, water, and medical aid. This federal effort included 1,500 personnel and 8,000 Coast Guard members tasked with restoring services and rescuing those affected.

The modern disaster response system in the U.S., coordinated by FEMA, has evolved since its establishment in 1979 under President Carter. With the rise of natural disasters stoked by climate change greenhouse gasses, FEMA has become a lifeline to Americans in the path of extreme weather.

However, FEMA's future may be uncertain. Project 2025, a proposed plan linked to the Heritage Foundation and supported by Republicans like Donald Trump and J.D. Vance, seeks to reduce FEMA's role in disaster response. The plan would shift responsibilities to state and local governments and dismantle the National Oceanic and Atmospheric Administration (NOAA), a key agency in weather forecasting and climate monitoring. Critics warn that such changes could weaken the nation's ability to respond to future natural disasters.

The aftermath of Helene highlights North Carolina's vulnerability to the effects of climate change. With warmer ocean temperatures contributing to stronger hurricanes, North Carolina has faced a steady increase in the intensity of storms over the past decade. This growing threat has sparked discussions about the need for more robust flood control measures, updated infrastructure, and improved disaster preparedness to protect against future storms in North Carolina and nationwide.

Experts, including NOAA, forecast an active hurricane season due to record-warm ocean temperatures. Jeff Masters, a NOAA scientist, noted that this is the eighth Category 4 or 5 hurricane to hit the U.S. in the last eight years, a record number for this period.

Attribution scientists from the ClimaMeter and Lawrence Berkeley say their initial Hurricane Helene computations show that rainfall totals were 20% heavier due to climate change, the winds 7% higher, and the devastation by Helene in Western North Carolina was made 50% more likely due to anthropogenic global warming. The ClimaMeter study came with a warning. "Without reducing greenhouse gas emissions, these events will strike larger portions of the U.S., affecting territories and communities previously sheltered from such phenomena. "Extreme precipitation in Hurricane Helene has been largely intensified by fossil fuel burning," stated co-author Davide Faranda, IPSL-CNRS, France.

Here is what is happening, in condensed form: Humankind is jamming the atmosphere with greenhouse gases. While carbon dioxide is not a particularly strong greenhouse gas, we have increased the concentration of CO2 dramatically.

The oceans are warming rapidly. Warm water evaporates faster, pushing more water vapor into the air.

The atmosphere is warmer. A warmed atmosphere holds more water vapor.

Raising ocean and atmosphere temperatures have added about 7% more water vapor. H2O, in turn, is a potent greenhouse gas. The fact warming oceans evaporate more water vapor is a dangerous feedback loop.

You can see there is danger here. We can be confused by climate change deniers when they claim water vapor is the cause of climate change.  What deniers are ignoring is that while water vapor is a potent greenhouse gas, they neglect to tell us the increase of water vapor is a feedback triggered primarily by the atmospheric warming carbon dioxide.  Studies show that water vapor feedback roughly doubles the warming caused initially by CO2.

Carbon dioxide (along with methane and nitrous oxide) causes global warming. Warmer water accelerates evaporation, amplifying the warming and obviously increasing the rainfall potential.  

Another uncomfortable truth is that carbon dioxide has a long residence time. Residence time is the time a gas hangs around in the air before natural processes remove it. Carbon dioxide slowly dissipates over decades. Some of the CO2 we are emitting today will still be trapping heat our kids will have to deal with 100 years from now.

Conversely, water vapor may stay as short as a few minutes before condensing. On average, its residence time is only  8-9 days. In a way, this is lucky since as it does not stay long shortening the time we have to deal with hot muggy nights.

Dangerously, if conditions are right, as just happened in North Carolina, the supersaturated air rapidly blows in from the Gulf of Mexico where it hits the mountains, rises, cools, and reaches its dew point. Cool air cannot hold as much water, and it condenses. Over the mountains of North Carolina 30 or more inches fell, flooding the mountain towns. In his preliminary calculations, meteorologist Ben Noll tells us the level of moisture transported to western North Carolina was more than 1.5 times greater than any event in the historical record for the region.

Here are additional disconcerting facts about the Asheville flood. The National Climatic Data Center is in Asheville. It will be a while before an in-depth, detailed analysis will come out of the agency.

Second, at 2 ,134 feet elevation, Asheville was considered a cool, safe climate haven. 

If we want the Great Lake states to remain the climate-safe havens we love, we had better get serious about climate change. Climate change is not a “Hoax”, as former President Trump has claimed. It is obviously real, deadly and we can defeat it.

That is what my 600+ science magazines tell me.

References: * “Vapor Storms” by Senior Scientist Jennifer Francis at the Woodwell Climate Research Center. Scientific American, November 2021

Skeptical Science Climate Myth #36.

USA Today, “Devastating Consequences: Climate Change Likely Worsened Floods after Helene.” October 3.