Heat Projections And Our Future Health - The Years Project

Heat Projections And Our Future Health

By Dr. Marc Futernick

I’ve been looking at some heat projections, both if we continue with business as usual, and if we cut our greenhouse gas emissions significantly. Either way, it will continue to get hotter until at least mid-century. The current nationwide heatwave likely represents the future normal on summer days, and the heat waves in the near future will be unbearable. In fact, they will be downright dangerous. 


I listened to a great podcast yesterday called Got Science? from Union of Concerned Scientists. In Episode 63: Killer Heat in the US, climate scientist Kristy Dahl discusses a study she led projecting the likely frequency of extremely hot days across the US, through 2100, under various scenarios.  The team used 18 well-validated models and averaged them. Heat Index combines actual temperature with humidity to provide a “feels like” measure which correlates well with the physiologic impacts of ambient heat.  A Heat Index greater than 100 is considered to be extremely hot, with demonstrable health consequences.

The bottom line is that by mid-century, the number of extremely hot days (Heat Index greater than 100) will double, on average, across the US.  More concerning, the number of days with Heat Index greater than 105 will triple in frequency. There was an interesting discussion on the podcast about the current formulas for the Heat Index being inadequate to describe the impact of heat at higher levels.  They call these situations “off the chart” and currently there are only a handful of such days in certain desert areas each year.  However, this modeling showed that 25% of the country will occasionally experience “off the chart” days, with some areas like Arizona experiencing them regularly during the summer months.


One initial reaction may be that we can simply prepare by making sure everyone has a cool area to stay and lots of water to drink. These are absolutely the right mitigation strategies, but the reality is that our current power systems are inadequate for the task, and power outages at these temperatures will be common and lethal. Florida, for instance, following the deaths of nursing home patients due to power outages, now requires backup generators at all nursing homes. What about the rest of the community, full of vulnerable people, who won’t have backup power?

Also consider the investment needed to install air conditioning in areas that currently don’t have it, such as San Francisco and the Atlantic Coast of the Northeast. There are lots of areas that will be dangerously hot in the coming decades that have never needed AC in the past. Consider the increased energy we will need to cool our cities.  Until we transition all the way to 100 percent clean energy, all of this excess power will come from the dirtiest sources, which are reserved for high capacity needs. This will further exacerbate the original problem of global warming from greenhouse gas emissions, resulting in yet another scary positive feedback loop that could accelerate the changes we’re seeing already.


We need to get off of fossil fuels as soon as possible, and also address greenhouse gas emission from other big sources such as agriculture and refrigerants.  On a personal level, consider going electric for your transportation.  I love my electric car, and there are more models coming out all the time.  I will do a future blast about this, but they are now equal in cost over their lifetime to the gas equivalent models.  You pay a bit more up front, but will save on maintenance and gas over the life of the car.  This doesn’t include the convenience of never having to service the car, and “filling up” at home rather than at a gas station.  Consider installing solar panels.  I view them as money machines, generating energy for decades.  Consider moving towards a plant-based diet.  Last, but not least, get active.  This is the greatest challenge facing our generation, and possibly any generation.  We need to push our elected officials to do the right thing, and we need to set the example personally.

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