Insane temperature increase next year

 From Zeke Hausfather

I'm not sure folks have realized just how crazy the second half of 2026 and 2027 will be for global temperatures – on the back of a record-smashing El Niño event. Here is my latest estimate of where both years will end up compared to global temperatures since 1850.

We're racing towards 2 degrees increase in temperatures since the 19th century.  And look how bad things already are.  The rate of increase is accelerating. 

Yet our politicians and CEOs lie to us, pretend to care, but take no action to slash emissions.  

April second warmest ever

 From Zeke Hausfather

April 2025 was the second warmest April on record (after 2024) in the ERA5 dataset, at around 1.51C above preindustrial levels.

With the first four months of the year now available, I estimate that 2025 is most likely to be the second warmest year on record at 1.52C in ERA5, with a ~8% chance of beating 2024 as the warmest and a ~25% chance of coming in at the third warmest after 2023.

Most days in 2024 exceeded 1.5 C warming

 From Zeke Hausfather

Gobsmackingly bananas

 In September, global temperatures charts went off the scale

ClimateCrocks:

The BBC:

From Denis Gilbert

Berkeley Earth report:

The following is a summary of global temperature conditions in Berkeley Earth’s analysis of September 2023.

• Globally, September 2023 was the warmest September — and the largest monthly anomaly of any month — since records began in 1850.
• The previous record for warmest September was broken by 0.5 °C (0.9 °F), a staggeringly large margin.
• Both land and ocean individually also set new records for the warmest September.
• The extra warmth added since August occurred primarily in polar regions, especially Antarctica.
• Antarctic sea ice set a new record for lowest seasonal maximum extent.
• Record warmth in 2023 is primarily a combined effect of global warming and a strengthening El Niño, but natural variability and other factors have also contributed.
• Particularly warm conditions occurred in the North Atlantic, Eastern Equatorial Pacific, South America, Central America, Europe, parts of Africa and the Middle East, Japan, and Antarctica.
• 77 countries, mostly in Europe and the tropics, set new monthly average records for September.
• El Niño continues to strengthen and is expected to continue into next year.
• 2023 is now virtually certain to become a new record warm year (>99% chance).
• 2023 is very likely (90% chance) to average more than 1.5 °C above our 1850-1900 baseline.

Yet still we dither and phaff, instead of moving aggressively to slash emissions.  Our politicians continue to accept bribes from fossil fuel companies.  Voters continues to let them do so.

July second hottest on record

 From a tweet by Zeke Hausfather

The first global temperature data for July is now in, and it was the 2nd warmest July on record in the
@CopernicusECMWF ERA5 dataset (only 2019 was warmer). July temperature have risen around 0.75C since 1979, and are current around 1.26 above preindustrial levels.

And this is a La Niña year, when temperatures are generally cooler.  What's more, with 'only' 1.26 degrees C increase since the second half of the 19th century, we are already getting record heatwaves, record floods, record bushfires and record droughts.  And emissions continue to rise.

Just how good were the early climate models?

Very good indeed.  

From a tweet by Zeke Hausfather 

For what it's worth, we have been projecting future warming since the first climate models in the late 1960s/early 1970s. We can look back to see how well they have performed. It turns out our models generally did a good job: