Meteorological institute KNMI worried about new reality with "erratic" climate

Erratic. That is the word the KNMI used to summarise the weather in 2024. It is also the direction in which the climate is increasingly moving. The Netherlands is already experiencing more extreme precipitation than it did a few decades ago. “A more erratic climate is our new reality,” wrote director Maarten van Aalst in the annual report The State of our Climate.

The increasing weather extremes are a cause for concern for the institute’s scientists. “We must be prepared for extremes we have never seen before,” warned Van Aalst. He added that there is still a lot of work to be done to better prepare the Netherlands for the consequences of climate change, such as the increasingly rapid rise in sea levels.

The institute previously announced that 2024 was, on average, just as warm for the Netherlands as the record year 2023. The heat record was equaled without a heat wave and with only four tropical days when maximums topped 30 degrees at the national measuring station in De Bilt, which is relatively few. The explanation is that the minimum temperatures were very high. In De Bilt, there was not a single ice day when temperatures remained below zero all day.

There were no ice days in 2023 either. The fact that this happened two years in a row has never happened before since temperature measurements began in 1901. The number of frost days, when temperatures remained below zero for part of the day, was 23 fewer than even last year.

There were plenty of mild days. Wet days too. The KNMI counted 13 days with extreme precipitation with more than 50 millimeters of rain falling locally. That happens more often in the changing climate because warm air can absorb more water vapor than cold air. Between August 2023 and July 2024, the Netherlands experienced the wettest period ever measured.

The number of days with heavy precipitation almost doubled in recent decades, from an average of five to nine per year. Last year, was therefore also an outlier in this respect, although it was not a record. 2021 counted 16 days with extremely heavy rainfall.

It is clear to the KNMI that the climate is changing so strongly due to greenhouse gas emissions. “Twenty years ago, the question was: are we sure that it is due to emissions?” said director Van Aalst. Now, the big question is mainly when the tipping points in the climate will be reached, resulting in even more severe climate change. According to climate scientists, this chance increases considerably above a temperature increase of 1.5 degrees.