We have had some very warm days, right across the Northern Hemisphere, this past week. Not just unpleasant in many areas, but deadly!
Along with the news reports, of course, come the claims that it has never been this hot or this is a sign of the impending doom of climate change.
Unfortunately, or perhaps what is more normal, people have short memories and journalists fail in their fact-checking and due diligence – or perhaps news outlets just like to exaggerate and scare people.
A very quick search of the Internet for “historic heat waves” comes up with over 600,000 hits. In looking through many of the old reports one realizes there were many times when people suffered from exceptionally hot days. (Next winter I will probably find similar reports of the opposite case, when reports come out that it has never been colder.)
Real, accurate and consistent temperature readings in most of the world do not go back more that a few of centuries. It is impossible to gauge the severity of heat waves that occurred prior to the 19th century with any reliability.
But it is easy to find report of heat waves that occurred during the last two centuries. I found a great webpage that details many heat waves in North America and Europe at Wanstead Mateo, “a blog about weather that affects Wanstead and the surrounding areas of east London and west Essex…” On the 26 June 2015 post there are a number of specific examples described along with a table that list the worst heat waves that affected London, England, since 1852.
There are dozens of other website that cover heat waves in North America and other parts of the world.
One major event happened in July 1757, during apparently the second hottest summer in Europe in over 500 years to that point. What is interesting about this one is that it occurred during the depth of the Little Ice Age.
The worst heat wave on record was in 2003, accompanied by very high humidity levels, which apparently killed 70,000 people in Europe.
The conclusion is that these weather anomalies are not unique to the 21st century, nor to any time period, actually. During the 20th century they happened at least once a decade with temperatures soaring past 90°F (32°C) or even 100° (38°C) for days on end. Deaths were common from hyperthermia, in recent decades more deadly than floods or hurricanes in North America.
As we search old records further will we find that some of our ancestors also suffered during prolonged heat waves, perhaps during many of the droughts and famines that were common in the 13th to 19th centuries?