When most people talk about the dangers of global warming and climate change they usually bring up sea level rise or extreme weather events as examples of what will happen if the problem remains unaddressed.
Some of the most savvy environmental activists even talk about the connection between climate change and geopolitical catastrophes such as the war in Syria.
However, most people neglect to talk about one of the most obvious consequences of global warming. Extreme heat.
It seems obvious but in an age where most Americans believe that access to central A/C is ubiquitous (even though it isn’t), heat waves & high heat events haven’t gotten the spotlight they deserve. Extreme heat is not only an increasing & ever-present danger to human health, but it will also jeopardize our food supply in the not so distant future
The now infamous European heat wave of 2003 led to the deaths of over 35,000 people across the continent (though some more recent calculations push that number to above 70,000 deaths). The French were hit particularly hard that summer with reports sighting 14,802 documented deaths attributable to the blistering heat and record-setting temperatures.
However, as we continue to dump more greenhouse gases into our atmosphere these sorts of record-setting heat events will become more and more common.
Between 1960 and 1989 Paris experienced a heatwave approximately once a decade; between 2020 and 2049 that frequency is projected to increase to one heat ware every two years!
This is not good news if you don’t have central A/C; however, according to the most recent survey conducted by the EIA (Energy Information Administration) more than 16 million homes here in the US don’t have access to either central or even single room (window) A/C.
Many of these people are poor, disabled, or elderly making them extremely vulnerable to the health risks associated with extreme heat events.
Others living in cold weather cities like Chicago who might only just be able to afford a reliable A/C unit may decide to forgo the expense in order to save money. However, cases like the 1995 Chicago heat wave, which in just a five-day span hospitalized 3300 people and took the lives of more than 600, serves as a cautionary tale.
In fact, those living in more temperate climates may be at higher risk because they aren’t accustomed to dealing with consecutive 90+ degrees F days.
Now those of us who enjoy the luxury of reliable central heating & cooling aren’t out of the woods either. An increase in extreme heat events will also put immense pressure on farmers and thus our global food supply.
In the United States agricultural professionals typically aren’t too concerned about marginal fluctuations in temperature and in fact, up until recently, most experts didn’t expect global warming (as opposed to other climatic disturbances such as changing precipitation patterns) to significantly affect US crop yield in the near term.
However, a recent analysis headed by David Battisti, Tamaki Endowed Chair and Professor of Atmospheric Science at the University of Washington, upended this consensus.
Normally changes in temperature only significantly reduce crop yield at the extremes and in the US, and mid-latitudes in general, we sit well within the optimal temperature range for most commercially grown crops.
So for example, if Iowa experiences a hotter than average summer, which would constitute an average temperature increase of a couple of degrees or so, that would only push their average summer temperature from 71.6 degrees F to around 74 degrees F (approximately 23 degrees C). The optimal growing temperature range for wheat is between 53 to 77 degrees F (12 to 25 degrees C) so wheat farmers in the state would see very little change in their crop yields.
Now let’s imagine in the year 2050 global warming has increased Iowa’s average summer temperature by 1.5 degrees C or 2.7 degrees F. Temperatures for a hotter than average Iowan summer would then hover around 28 degrees C or 82 degrees F, and now we have a problem.
Outside of the optimal temperature range wheat yields reduce dramatically as the graph above illustrates; during this hotter than average summer, the same farmer in 2050 will experience a yield reduction of more than 25% percent.
If you push that temperature increase to 1.8 degrees F or just 1 degrees C, that farmer’s wheat crop would be all but lost. Such volatility would be devastating to the agricultural sector.
Combine that with perennial drought, soil degradation, and continued population growth and you have the makings of global food shortage,
This is why scientist say that global warming above 2 degrees C is so dangerous.
Society often feels so robust to change but the fact is that our way of life rests on an extremely fragile foundation. Rising temperatures all on their own provide enough of a jolt to the system to cause major disturbances and crises. So when you’re talking to your friends and family about the danger of climate change, don’t forget the heat.
