Climate in Transition – How We Become More Resilient

The heat waves that hit us every summer and the growing dryness make one thing clear: the climate is changing. What we haven’t yet taken to heart is that we must change along with it. Al Gore, the former US presidential candidate, coined the phrase back in 2007: “The Earth has a fever – and the fever is rising.” We’ve long since caught that fever ourselves.

Researchers have been pointing out for a long time that “mitigation” – limiting and softening climate change, above all through fewer CO₂ emissions – must be joined by “adaptation”: adjusting to those consequences that are already being felt.

Too hot, too dry, too extreme

Extreme weather events shouldn’t just frighten us; they must spur us into action. The 1.5-degree target at the heart of the Paris Climate Agreement has drifted far out of reach, while tipping points with irreversible consequences loom at the same time.

This development shows most clearly in the case of water. Water isn’t everything – but without water, everything is nothing. There can be too much of it, when heavy rainfall or rising sea levels threaten and destroy habitats. But too little is just as problematic, when heat and droughts threaten harvests in the Global South and deserts keep spreading.

If the distribution of water falls out of balance, the consequences are dire. According to the UN, one in four people on Earth today has no access to clean drinking water. Millions of people are being driven to flee. Wars over water are no longer just visions from apocalyptic disaster blockbusters. Humanity’s future will depend on how it manages this element.

Solutions from the laboratories of our time

Should we now give up in the face of water scarcity and global warming – with all their consequences? It would be better if politics and business responded decisively – but research, too, should offer solutions. Resignation and panic don’t help. Good approaches already exist; we simply have to put them into practice consistently. Then we can get the fever under control!

Take renewable energy, for example. Africa holds enormous potential here: around 60 percent of the world’s best solar resources are found there, yet the continent covers only about 1 percent of global solar energy output. That’s a bitter irony, because African states could export electricity and thereby generate new revenue, while at the same time becoming less dependent on increasingly shrinking development aid. What’s needed is an initiative on the same scale as the one pursued by the North Sea countries in Europe around offshore wind power, which has, quite literally, the wind at its back.

At the same time, people worldwide must adapt to the already unavoidable consequences of climate change. Investments in climate-resilient infrastructure, smart flood protection, and sustainable agriculture, along with the regeneration of our forests, are just as important as reducing emissions.

The country needs new cities

How closely climate protection, adaptation, and water are linked is shown by our own consumption. According to the WWF, producing a single fast-food meal requires 6,000 liters of water. A kilogram of avocados needs up to 2,000 liters before it can be harvested. 70 percent of the world’s freshwater consumption goes to agriculture.

And it isn’t just that area of consumption: manufacturing a single pair of standard blue jeans consumes roughly 7,500 to 10,000 liters of water. A significant share of that goes into growing the cotton, since the plants need intensive irrigation in dry regions.
We have a global transport of water from South to North – even though the Global South has long been far too dry.

What applies to water in a global context becomes very concrete in the cities of industrialized nations. They can make an important contribution by creating more green spaces, parks, and trees, and by greening roofs and façades. Sweden and Norway, for instance, have centuries of tradition with green roofs – knowledge the whole world can benefit from. If these buildings are also better insulated and heated in a resource-efficient way, a great deal is gained.
Urban planners should also implement the sponge city principle: permeable surfaces, water reservoirs, and green areas can better absorb heavy rainfall and offset flooding.

Visions for the weather – with digital twins

For such decisions to be not just well-intentioned but well-founded, we need data. One thing is beyond doubt: we will only master climate change if we base our decisions on a scientific and socio-technical foundation. This is exactly where digital twins of complex systems can be a game changer – something we are also researching at the Helmholtz-Zentrum Hereon, in cooperation with science, business, and civil society worldwide.

Digital twins make it possible to map systems such as an entire city virtually and to simulate the impact of measures before they are implemented. Cities can test where more trees would have the greatest cooling effect, which roofs are suited for solar panels or greening, and how new bike lanes would affect traffic. They can reveal which neighborhoods are most burdened during heat waves or where flooding is likely to occur during heavy rainfall.

The principle of digital twins reaches beyond the boundaries of a single city – for example, all the way to the world’s oceans. How do we understand our ocean and coastal systems? How can we map them digitally and project future developments? And how do we answer entirely different questions of resilience – for instance, how new materials can make the world fit for the climate of the future while also becoming more sustainable over their life cycle.
From climate action, through water as the basis of life, to the tools of urban planning: better decisions matter worldwide for the cities and countryside of the future. And, with them, for the people who live there.

We can bring the Earth’s fever down!