There is summer pain instead of summer freshness: extreme weather is scary. But we can do a lot to cool cities and landscapes.
The only clouds that form over monoculture forests are clouds of smoke Photo: Gov. of Alberta Fire Service/dpa
Italy, Spain, Greece, Algeria – around the Mediterranean, people and nature suffer from extreme heat, drought and forest fires. The feeling of life dolce vita burns. The time has passed when we could enjoy the turquoise blue Mediterranean Sea. Instead: summer pain. sadness and fear of heat. But sinking into powerlessness and depression now would be completely wrong. Around to cool cities and landscapeswe can do a great deal.
If we imagine the earth as a living planet, then rivers are its veins and trees are its sweat glands. Plants consume water and thus provide evaporative cooling, clouds and new precipitation. This cools our earth enormously and keeps its water cycles going. A single large tree evaporates around 400 liters on a summer’s day, cooling its surroundings like ten air conditioners running at the same time.
It also emits tiny bioparticles that promote rain because water molecules can attach to them. About half of the precipitation does not occur over the sea but over land – the percentage varies depending on the geographical situation. Basically, the rain does not fall from the sky, but is generated in the ground.
As microbiologist Masanobu Fukuoka put it: “Desertification is not due to the lack of rain, but rather the rain stops falling because vegetation has disappeared.”
Alternating droughts and heavy rains
However, the effects of missing green and blue have long been underestimated by climate science. Not just CO2the massive damage to the “skin of the earth” also causes alternating droughts and heavy rain because the dampening and cooling elements are missing.
Desert does not come from a lack of rain, rain stops falling because vegetation has gone
But water is still treated more as waste water than as an irreplaceable element of life: it is drained off by ditches in fields and by sewage systems in cities. It ends up in the ocean, further raising sea levels as continents slowly dry out.
In Germany, around 54 hectares of greenery disappear under new buildings and roads every day. Asphalt, however, stores heat, just like bare ground: in 2022, we measured almost 70 degrees on a harvested corn field.
Lack of evaporation creates heat islands and even more drought. Soil moisture is decreasing and groundwater is sinking – even in Germany, which is actually rainy. Even if July 2023 brought more rain than usual: According to the drought monitor of the Helmholtz Center for Environmental Research, there is still an “extraordinary drought” in large parts of Germany at a depth of 1.8 meters.
Slow water is the motto
But the literal devastation of the planet can be stopped. Countless examples around the world show the enormous potential of natural climate solutions that has not yet been remotely exploited.
This includes the renaturation from bogs, wetlands and rivers; Afforestation of climate-resistant mixed forests and the seas with algae, seaweed and mangroves; Methods of regenerative agriculture such as agroforestry (trees on the field), mobgrazing (keeping herd animals close together, moving fences every day), keyline design (water storage parallel to the height), catch crops, mixed cultures.
Sometimes it is enough to slow down watercourses with tree trunks and small mounds of earth, so that water is stored in the ground again. Slow water! is the slogan.
Studies have shown that summer precipitation in Europe, which is now lacking in the Mediterranean – individual heavy rains do not change the drama – could be increased by afforestation of semi-natural forests without loss of cultivation. According to Ronny Meier from ETH Zurich, particularly large effects can be expected in parts of Germany, western and southwestern France, on the Iberian Peninsula, in Italy and the Adriatic coast down to Greece.
The Spanish meteorologist Millán Millán believes that the Mediterranean region is drying up mainly because humid sea air no longer encounters coastal forests and can rain down there. This would change rain patterns across Europe. Ergo, the afforestation of coasts would be particularly effective.
Cities that can suck
“The main reason why the Mediterranean region dries up is because humid sea air no longer encounters coastal forests and can rain down there. This will change rain patterns across Europe”
The conversion of our cities into “sponge cities” could also have enormous effects. This means that settlements are soaked when it rains and floods and the water can slowly evaporate when it is hot. Copenhagen and other metropolises are leading the way: with green roofs, green facades, roof gardens, water retention basins under parks, fresh air corridors and more.
Almost everyone can participate in such a “greening” and “blueing”. Owners can, for example, place rain barrels under gutters or put lawns through them drought-resistant wild herbs substitute. Tenants, who often suffer particularly badly in hot inner cities, can put pressure on planted “super blocks” like in Barcelona, ??or derelict areas “Tiny Forests” rebuild. Check out our book for more ideas. All of this could be life-saving in the coming hot summers.
According to a team from ETH Zurich that studied 300 cities in Europe, places with lots of trees are up to 12 degrees cooler; they also dampen heavy rain and floods. While local groups cannot use the CO2-Decrease the content of the atmosphere, but the temperatures on site – in individual cases up to 20 degrees.
Natural climate solutions are cheap, effective and, in addition to the CO2-Saving countless win-win effects for biodiversity and human health. They only lack one thing: a strong lobby. Recently, an alliance of conservatives, farmers’ associations and the chemical industry almost killed the renaturation approaches in the EU Parliament. So we should all become their lobby. Just to be back dolce vita to experience in intact nature.
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