Headlines across the country announced that the global average temperature hit 17.18 degrees Celsius (62.924 Fahrenheit) July 4, the highest recorded temperature.
“This week saw the hottest global temperature ever recorded,” CNN reported, linking to a story about the impacts of drought in Afghanistan, a nation with some of the lowest rates of fossil fuel use in the world.
Citing the same source, The Washington Post reported that it was the hottest day since at least 1979. The article then goes on to state that 57 million were “exposed” to dangerous heat. This is according to the publication’s own source, and it means that 57 million people in the U.S. lived where temperatures got up to at least 103 degrees Fahrenheit at some point on July 4.
In other words, it’s summer.
Temperature Deaths
The concern about rising heat is that it will kill people. Deaths from heat have increased about 0.21% in the past 20 years, according to the International Disaster Database.
However, the impacts of rising temperatures on people is as complex as the climate.
The number of deaths from natural disasters has dropped 99% since 1920. This is a drop from millions of deaths per year to an average of 60,000 over the past decade for all disasters.
Worldwide, disasters were responsible for 0.1% of deaths over the past decade.
Temperature extremes are one area where there has been an increase. In total, an average of 3,925 people died each decade since the 1980s. The per-capita death rate, which factors in changes in population, rose from 0.01 per 100,000 people in the 1980s to 0.02 in the 1990s. Then, it jumped to 0.14 in the 2000s, before falling to 0.11 in 2010s.
Falling Cold Deaths
Since there are only three years in this decade, there’s no average for the 2020s, but in 2021 — the latest year in which data is available —- 1,044 people worldwide died from temperature extremes.
By contrast, according to the World Health Organization, 1.2 million people die every year in car accidents.
As deaths from heat rise, deaths from cold are decreasing. Since the International Disaster Database doesn’t count people who don’t die, these numbers aren’t reflected in the data.
Bjorn Lomborg, Danish author and the president of the think tank Copenhagen Consensus Center, calculated how many deaths are averted as a result of global warming.
According to one study in the renowned medical journal The Lancet, 600,000 people die globally from heat, but 4.5 million people die from cold.
Higher temperatures, Bjorn calculated, caused 116,000 more deaths between 2000 and 2019, but another 283,000 cold deaths were avoided because of warmer temperatures.
Complexities
There is an observed, documented warming trend, but the Earth’s climate is an enormously complex system. Quantifying its state in a single temperature leaves out a lot of nuance.
For example, July 4 was the hottest day on record and not the hottest day the Earth — or even the human race — has seen. The records only go back to 1979.
There are ways of determining temperatures before we had direct measurements. Some studies using this data conclude that temperatures were much higher in the past. These proxies, as they’re called, aren’t as reliable as direct measurements, so there is much debate over their accuracy.
Suitable Numbers
Even direct measurements contain uncertainties.
The source these media reports of the “hottest day ever” are going off of is the National Centers for Environmental Prediction (NCEP), and they link to Climate Reanalyzer.
Ryan Maue, a research meteorologist, explains that this is not an official NCEP temperature monitoring product. It’s a crude weather model output that’s not suitable for climate analysis, and is actually from the University of Maine. The data quality is low, Maue said, and it should only be used for preliminary or initial data analysis.
A much better source is the ERA5, and preliminary data shows the global average temperature Monday was 16.88 degrees Celsius, breaking the previous record of 16.8 degrees Celsius (62.24 F) set in 2016.
So, in seven years, we saw a record break by 0.08 degrees Celsius (0.144 F).
Not That Important
Maue told Cowboy State Daily the different data sets are really not that important for looking at daily average global temperatures.
They “could have some importance for declaring with the 1.5 degrees Celsius threshold is passed for the Paris Agreement,” Maue said, referring to the 2015 international treaty on climate change.
Nations who signed onto the agreement agreed to meet certain targets of carbon dioxide emission reductions by certain dates. The United States had signed onto the agreement, but former President Donald Trump withdrew the U.S. from it. Shortly after taking office, President Joe Biden signed the United States back on to the agreement.
Maue also noted that this difference of 0.08 degrees Celsius doesn’t have a lot of meaning.
“As nothing has happened to anyone on Earth in particular as the global temperature rose to 17 C, what’s the importance of a ‘global temperature?’” Maue said.
Dynamic And Variable
Dr. Matt Wielicki, former assistant professor in the Department of Geological Sciences at the University of Alabama and author of “Irrational Fear,” told Cowboy State Daily that the methods of measurement to come to this global average temperature are too imprecise to measure temperature to a second decimal place.
“We're measuring in thousands of little locations, and then we're extrapolating another 90% or more. If you are really being honest about the errors, we don't know a global average temperature to that metric,” Wielicki said.
He compared the exercise of determining a global average temperature by the day to coming up with the average number in the phone book. Even if you could precisely determine that number, it doesn’t have any meaning.
“It doesn't hold nearly as much meaning as the mainstream media likes to put onto it, because it reduces a really dynamic and variable system into a single number,” Wielicki said.
