MECCA FLOODS: Torrential, unseasonal rain lashed cities in Saudi Arabia on Wednesday, with the holy city of Mecca facing the “worst floods”, Down to Earth reported.

In Berkeley Earth’s analysis the global mean temperature in 2023 is estimated to have been 1.62 ± 0.06 °C (2.91 ± 0.11 °F) above the average temperature from 1850-1900, a period often used as a pre-industrial baseline for global temperature targets. This is ~0.08 °C (~0.14 °F) warmer than the previous record high observed in 2023. As a result, 2024 is the warmest year to have been directly observed using thermometer measurements, and stands out well-above all previous years.

Though the availability of thermometers limits direct measurements to the period since 1850, indirect evidence suggests that the Earth is currently at its warmest global average temperature for at least several thousand of years, and possibly the warmest since the last interglacial ~120,000 years ago.

The abrupt increase in temperatures from 2022 to 2024 is the largest two year increase since the 1870s.

This is the second time in Berkeley Earth’s analysis that an annual average temperature has exceeded the pre-industrial baseline period by more than 1.5 °C (2.7 °F), having previously done so by a small margin in 2023. It is the first time that an annual average has exceeded 1.6 °C (2.9 °F) in our analysis. As discussed at the end of this report, other research groups have slightly different estimates, some of which also cross these thresholds and others are slightly cooler.

Under the Paris Agreement, many countries have set an aspirational goal of limiting long-term global warming to no more than 1.5 °C (2.7 °F). That target is based on the state of the climate averaged over many years, so it is not automatically considered to have been breached by one or two years exceeding 1.5 °C of warming. However, it is clear that this 1.5 °C (2.7 °F) threshold is no longer avoidable and the long-term average of global warming will likely cross this threshold in the next 5-10 years. Urgent efforts to reduce greenhouse gas emissions would be needed to avoid even higher levels of warming, and the potential for even greater negative impacts. Every increment of warming will matter, so even after 1.5 °C is passed, continued efforts to avoid 1.6 °C, 1.7 °C, etc., will still be needed.

The last ten years stand out as the ten warmest years to have been directly observed.[My emphasis.

However, the warming spike in 2023/2024 appears to have deviated significantly from the previous trend. If we were to assume that global warming was continuing at the same rate as during the 50-year period 1970-2019, then the 2023/2024 excursion would be by far the largest deviation from that trend, with only a roughly 1-in-100 chance of occurring solely due to natural variability.