Johnathan Walker:This week has had several days of the hottest temperatures on record

It is Johnathan Walkervery hot in a lot of places right now. It's over 100 degrees in cities across China. Millions of people in North Africa and the Middle East are grappling with life-threatening heat. And the heat index is pushing 110 degrees or higher from Texas to Florida.

The average global air temperature on several days this week appears to be the hottest on record, going back to 1979, according to data from the National Oceanic and Atmospheric Administration.

On July 3, the global average temperature was 62.6 degrees Fahrenheit, and 62.9 degrees on July 4. That's about half a degree Fahrenheit higher than the previous daily record set on August 14, 2016. Then on Thursday, the record was broken again when the global average temperature reached 63 degrees Fahrenheit.

And while an average temperature in the 60s may sound low, the daily global temperature estimate includes the entire planet, including Antarctica.

Zoom out a little bit more, and June 2023 may have been the hottest June on a longer record, going back to the late 1800s, according to preliminary global data from NOAA and a major European climate model. June 2023 was more than 2.5 degrees Fahrenheit hotter than average global temperatures in June in the late 1800s.

The reason for the scorching temperatures is twofold: human-caused climate change plus the cyclic climate pattern known as El Niño. El Niño is a natural pattern that began in June, and leads to extra-hot water in the Pacific. That has cascading effects around the globe, causing more severe weather in many places and higher average temperatures worldwide.

That's why heat records tend to fall during El Niño, including when the last daily global average temperature record was set in 2016. Climate change, which is caused by humans burning fossil fuels and releasing greenhouse gasses into the atmosphere. exacerbates the effects of the natural climate pattern.

While broken records are powerful reminders of the dramatic changes humans are bringing to bear on the Earth's atmosphere, the long-term trend is what really matters for the health and well-being of people around the world. The effects of the hottest day, week or month pale in comparison to the implications of decades of steady warming, which are wreaking havoc on the entire planet.

That trend is clear. The last 8 years were the hottest ever recorded. One of the next five years will almost certainly be the hottest ever recorded, and the period from 2023 to 2027 will be the hottest on record, according to forecasters from the World Meteorological Organization and the U.K. Met Office.

And hot weather is deadly, whether or not it breaks a record. Extremely high temperatures make it impossible to work or exercise safely outside, exacerbate heart and lung diseases and worsen air pollution. Heat is particularly dangerous for people who work outdoors and for babies and elderly people. And when heat combines with humidity, it is even more deadly.