One reason is that the carbon dioxide concentration in Mauna Loa was 424 parts per million in May.
That’s more than 50% higher than before the industrial era began roughly 250 years ago and 3 parts per million higher than what federal scientists counted in May 2022. It represents the fourth-largest annual increase since the National Oceanic and Atmospheric Administration started its tally 65 years ago.
This trend is pushing the Arctic toward ice-free summers as soon as the 2030s.
The loss of summer sea ice would trigger a feedback loop known as "Arctic amplification" with the dark ocean absorbing more solar heat and causing additional planetary warming.
And the emergence of the El Niño pattern in the Pacific Ocean only intensifies extreme weather events.
The effects of El Niño tend to peak during December, but the impact typically takes time to spread across the globe. This lagged effect is why forecasters believe 2024 could be the first year that humanity surpasses [warming of] 1.5 degrees Celsius. Global average temperatures in 2022 were 1.1 degrees Celsius warmer when compared to the late 19th century.
Update (July 5): Well, that was fast.
On Tuesday, the global average temperature peaked at a new all-time high of 17.18 degrees Celsius [62.92 degrees Fahrenheit] as regions worldwide—from Asia to Africa to the U.S. South—reeled from dangerous heatwaves.
Update (July 6): Apparently, Wednesday tied Tuesday's record. Brian McNoldy:
It's so far out of line of what's been observed that it's hard to wrap your head around. It doesn't seem real.
Update (July 7): The new (unofficial) record, set Thursday, is 63.01 degrees Fahrenheit.
Update (July 15): No new global records yet, but the southwest U.S. is blazing.
Nearly a third of Americans were under extreme heat advisories, watches and warnings. The blistering heat wave was forecast to get worse this weekend for Nevada, Arizona and California, where desert temperatures were predicted to soar in parts past 120 degrees Fahrenheit (48.8 degrees Celsius) during the day, and remain in the 90s F (above 32.2 C) overnight.
Phoenix marked the city’s 15th consecutive day of 110 degrees Fahrenheit (43.3 degrees Celsius) or higher temperatures on Friday, hitting 116 degrees Fahrenheit (46.6 degrees Celsius) by late afternoon, and putting it on track to beat the longest measured stretch of such heat. The record is 18 days, recorded in 1974.
Update (July 26): World Weather Attribution claims that this month's record heat would be "virtually impossible" in the absence of anthropogenic climate change.
Update (September 10): Phoenix continues to set new heat records for 110 degree Fahrenheit days.
[Saturday] was the 54th day this year that the official reading at Phoenix Sky Harbor Airport made the mark, eclipsing the previous record of 53 days set in 2020.
In July, Phoenix also set a record with a 31-day streak of highs at or above 110 F (43.3 C). The previous record of 18 straight days was set in 1974.
