Full terraces, shorts: a summer start of darkness

The beaches are full. Hedgehogs postpone their hibernation. Leaves doubt whether they will fall. The magnolia has buds again. In the Netherlands, the average temperature these days hovers about 6 degrees Celsius above the average of the past thirty years. Friday was the warmest October 28 on record. The summer temperatures are due to a southerly current that moves from Spain across the Bay of Biscay to the Low Countries.

Meteorologists and climatologists from the KNMI are not surprised when asked, but it is of course special: since the measurements started in 1901, the temperature had risen above 20 degrees only four times in the last week of October, at least in De Bilt. . This happened twenty times in Maastricht. Especially in 2005 it was also warm. The winter time will start this Saturday night, with summer temperatures, without a bitter storm and cold rain, and without the thoughts going to gloves and skating fun. High school students celebrate Halloween.

Report marks

There is a great temptation to take the mild autumn as new evidence that humanity is helping the planet to doom – it’s climate change stupid. Then the autumn heat could be interpreted as the symbolic culmination of a week in which the bad report numbers were flying around us again; the United Nations Environment Agency notes that governments worldwide are doing far too little against climate change and that the world is heading for warming to an average of almost three degrees by the end of this century; the World Meteorological Organization reports that world record amounts of carbon dioxide, methane and nitrous oxide were measured in the air last year.

Also read: Global warming a little less disastrous

A beach day in October would fit right in with this constellation, you might think. But the meteorologists and climatologists of the KNMI are not relentless so easily. Climate researcher Peter Siegmund: “The whole world is warming up, all seasons are getting warmer, also in the Netherlands. But the current heat is mainly due to chance and to some extent on climate change.

“The current temperatures are a result of a southerly wind that arises between a low-pressure area to the west of our country and a high-pressure area to the east. Climate change has no influence on that. Climate change does increase the chance of temperature records, the chance of extremes.” The KNMI does not know how great that chance is.

It is significantly warmer than normal throughout Europe. In parts of France and Spain it is even more than ten degrees warmer than average. “Long live climate change”, cheers a friend from the beach in Barcelona.

“Nature can take a beating, but if we’re not careful, the system will go awry”

Not too far from there is Zaragoza, a city about which climatologist Siegmund looked up the statistics. The maximum temperature there is now about 27 degrees Celsius, something that has happened only five times before in the last week of October since 1951. Siegmund: “So yes, it is also very warm there for the time of year.” We hardly dare to look at the temperatures in Greenland, where it is more than 10 degrees Celsius warmer than normal. As long as the ice there doesn’t melt faster. What a comfort to learn this week that a study by Utrecht University, among others, shows that in the worst case in two hundred years a sea level rise of nine to ten meters cannot be ruled out, but that if the earth warms strongly, By the end of this century, the global sea level will not have risen by an average of 1.6 meters at most, but by ‘only’ 1.3 metres. A stroke of luck.

Shorts

In the meantime, daredevils walk in shorts in the Netherlands. Weeds creep up from the tiles again. Berms are being mowed again. Screens will be placed again because there are many more insects flying than usual in October; hoverflies and mosquitoes, bees and dragonflies, butterflies.

Ecologists and forest rangers have different opinions about how and why. Some argue that higher temperatures offer insects more chance to reproduce, others point out that the insects are then no longer eaten by the birds, hence the surplus. After all, the bird migration had already started, the swallows are gone.

Others argue that as a result of the high temperatures, other birds have arrived. “Some of the robins and great tits that we now see come from Scandinavia and Eastern Europe,” says biologist Arnold van Vliet of Wageningen University. There is also a good chance that walkers along streams and rivers will encounter many kingfishers; not only the parent pairs but also young kingfishers, which survive much easier than usual with these temperatures. “Just keep an eye on it,” says ecologist Arnout-Jan Rossenaar of Staatsbosbeheer.

It is also not clear how the heat will turn out for animals that postpone their hibernation. “Can they come out of hibernation weakened?” asks forester Mathiska Lont of Natuurmonumenten. Or are hedgehogs and mice now building up so many reserves that they will soon be able to start spring in good spirits?

Anyway, the high temperatures of the past year are not comfortable for most ecologists. “Nature can take a beating, but if we’re not careful, the system will go awry,” says forest ranger Mathiska Lont. Biologist Arnold van Vliet: “This year it was extremely hot, very dry and very sunny. It goes on and on. Nature no longer gets a breather. This is not good.”