It will be settled at the end, but the trend is already clear: The winter of 2022/23 is expected to be significantly too mild again, only a historically cold February could turn the winter balance into the negative. But it does not look like that at the moment. Grim cold is not to be expected for the time being, it remains too mild for the season. Thus, the country is experiencing the twelfth too warm winter in a row, gradually the winter says goodbye to our latitudes. And with that, ice and snow disappear – the cold season loses its terror.
This is good news for heat lovers and the level of the gas storage tanks, but cold fans are experiencing hard times. And nature is facing drastic changes. This is especially true for cold-adapted animals and plants, because the warming of the past decades was just the beginning. By the end of the century, climate researchers expect even warmer winters, permanent frost and snow are becoming more and more the exception. In any case, biologists and ecologists fear the worst. Some refrigeration specialists are unlikely to survive the warming trend in the long term, at least here on land, they say, the pressure to adapt is overwhelming them. In addition, climate change is increasingly disrupting the well-established rhythm of nature.
The cold specialists of the high mountains are particularly threatened.
The alpine snaphase, for example, color its fur white in winter and camouflages itself on the snow surfaces.
However, long parts of the Alps remain brown, as this winter, the hare becomes slight prey for fox and hawk.
This danger is also exposed to the snow chicken, which changes its feather dress from brown to white in autumn.
In any case, the German Wildlife Foundation is rather pessimistic about the future of the chicken.
Because climate change increases the problem, and population density and number of offspring are low, says Klaus Hackländer, the chairman of the wildlife foundation in a press release.
The world gets out of rhythm
Fortunately, the situation with the snow sparrow, which occurs from about 1900 meters above the meter to almost the highest mountain levels, is not so bad yet. Nevertheless, the ornithologists also record decreasing stocks. In Switzerland, they have fallen by 20 to 30 percent since 1990, according to the Sempach Ornithological Institute. The big brother of the house sparrow is having a hard time coping with the strong environmental changes.
The researchers see the main reason for this in the fact that the temporal interaction between the slip time of the snowmers and the melting of snow is disturbed, since it is always caused by climate change. As a result, the well -rehearsed balance of the ecosystem gets mixed up. Because normally the sparrow boys always hatch around the time when the snow melting uses. At the edges of the snow fields, the adult animals that feed on grains will find those insects and their larvae that they feed on the offspring. But since the animals have not adapted to the now premature melt, an early spring is more and more dangerous to the breeding success of the snowmers. The timing between reproductive time and the maximum food supply simply no longer fits.
But it is precisely timing that matters if reproduction and growth of a species are to be successful. Plants and animals orient themselves on typical clocks such as temperature in order to be able to enter the next stage of the annual cycle. If they are prevented from doing so by environmental changes, ecologists speak of "ecological mismatch". The English marine biologist David Cushing described the phenomenon back in 1969, but it is only through climate change that it becomes more explosive. This is because the interaction between climate and development, which has been precisely coordinated over centuries, is getting out of sync with more and more species. The balance of the ecosystem is disturbed.
The early start of many species is evidenced by the numerous phenological observations, plants and animals react strongly to temperature in their annual development cycles. Since the 1970s, biologists have been observing a clear premature trend in Europe, flowering and leaf development have since shifted forward – depending on the species – one to four days per decade. As a result, certain pointer plants such as forsythia, which marks the first spring with its flowering, start earlier and earlier, on average about ten days earlier than 30 years ago.
Hazard blossom in January
Since autumn also begins later and later, the phenological winter, which is based on these indicator plants, has shortened from 120 days to 102 days, the German Weather Service has found. In the meantime, early spring arrives on average in mid-February with the hazel blossom, about two weeks earlier than before. This year, the first hazel flowers were even observed during the historic heat wave at the beginning of January.
This continuous premature development has consequences: biologists observe such shifts, known as asynchronous phenological phases, in numerous bird species. Migratory birds that travel long distances are particularly affected. As a result, they arrive at the wrong time in the breeding habitat – the breeding success decreases. An example of this is the pied flycatcher, which winters in West Africa and flies the 5000 kilometers back to Germany at the latest at the beginning of May. He eats mainly flying insects, for the young he needs caterpillars. But when he returns from his winter territory, the caterpillars have usually already pupated, and he also comes into conflict with great tits. As a result, the breeding success of the pied flycatcher decreases, the offspring makes its way to Africa next autumn weakened, many do not come back. As a result, its stock has already fallen by 90 percent in some regions of Europe.
Similar problems observe ornithologists in many birds that move south over long distances, such as the golden pastry or the nightingale. Since your train behavior is more genetically anchored, you can only react sluggishly to the early spring due to climate change. In any case, the ornithologists have a clear loss of many of these long -distance educators. Short -haul pullers, on the other hand, react faster to mild winter, classic migratory birds such as Kiebitz and star now stay here all year round.
Late frost becomes a problem
In principle, less susceptible to mild winter are many mammals that hibernate. They react primarily to daily lengths that are controlled via the internal clock, but their activity increases with longer mild weather phases. However, if hibernation is disturbed, the animals consume important energy reserves. For example, hedgehogs are dependent on such reserves in order to wake up from hibernation in spring and to be able to start the summer half year. To do this, burn the brown adipose tissue to let your body temperature rise quickly. And even with amphibians, the air temperature alone is not decisive for the beginning of their spring hike. Their behavior is also largely determined by the length of the day, and in addition to the temperature, they also react to a certain humidity before venturing out of their hiding places.
A phenomenon that is becoming more and more of a problem in a warmer climate then becomes really dangerous for the animals: late frosts. For amphibians and mammals, late frosts are life-threatening because they cannot simply return to their winter quarters. But agriculture is also threatened by climate change by more frequent flower massacres, as Berlin researchers have shown in a study for the apple blossom. The earlier the trees sprout, the more vulnerable they become.
And the timing of the flowering development of fruit trees has become significantly premature in Germany. However, the relationships between crops are much more complex than they appear, says agricultural meteorologist Bianca Plückhahn from the German Weather Service in Offenbach. After all, woody plants need not only warm temperatures to knock out early, but also a certain cold stimulus in the form of frost. In principle, mild winters had a negative effect on flowering and fruit set, says the expert, but this trend does not have to remain that way. Breeding also has a say in the future, she says. In any case, the pressure to adapt is growing.
Warm winter also damage agriculture
A similar balance can also be drawn for cereals, warmer temperatures accelerate the development of plants and reduce yield. Bianca Plückhahn notes that grain also depends on the date of sowing. The first farmers in the warm regions of the country have already started to sow spring barley in autumn or winter, and winter barley is increasingly affected by climate change. "It's worth rethinking the classic cultivation method," says Plückhahn.
Warmer winter temperatures also have consequences for the soil. Without cold air breaks, it freezes less and less often, the so-called frostgare, in which freezing water pushes the crumb apart, does not occur. As a result, the soil is loosened and ventilated less often. To make matters worse, in large parts of Germany the spring is getting drier and drier. Especially this trend is fatal: because in the growth phase, the cultivated plants need above all water and the nutrients dissolved in it. However, if the soils fall dry more and more often, this not only has a negative effect on yields, but on all living things in the soil as well as on the soil structure – dry soils are more susceptible to erosion. In addition, such plants and animals that are not welcome in the field, including weeds or even harmful insects such as corn borer and Colorado beetle, also benefit from the increasing warming.
In the end, a warm winter doesn't just do more work, it prevents the farmers from it. Because with the higher temperatures, the climate researchers expect more rain: the floors are more often in winter. So that the soil does not be slapped or compacted, it is better not to drive the tractor onto the field. Field work with climate change will certainly not be easier.
