It is the great dilemma of the climate crisis: the earth continues to heat up.
Even if we were to take radical countermeasures now, it would take years for the efforts to have an effect.
In which the earth continues to heat up.
Scientists have therefore been playing with the idea of protecting the planet from the sun for a long time.
Solar geoengineering is the name of the discipline.
One of the ideas: using aerosols to multiply the water droplets in the clouds.
"You could do that, for example, by whirling up sea salt from ships," says Johannes Quaas, professor of theoretical meteorology at the University of Leipzig.
"The reason is that sea salt is being thrown up over the ocean anyway and that it falls back into the ocean after a week."
Many water droplets in the clouds have a cooling effect on the ground because little sun shines through, but also have a reflective effect upwards because the clouds are much brighter when viewed from above.
More sun is reflected back.
Both of these help cool the planet.
Another idea: imitate an artificial volcanic eruption. With the help of airplanes, sulfur particles are to be transported into the stratosphere, which would otherwise arise in an eruption. “These sulfur particles have the property that they scatter sunlight. This means that the particles reflect part of the incident sunlight back into space, which means that less light reaches us on the ground, ”says Ulrike Niemeier. She is a Senior Scientist at the Max Planck Institute for Meteorology and has been studying volcanoes and their effects on the climate for many years. “A volcanic eruption is something very local. But there are very strong winds at these heights that distribute these particles across the globe. "
The ideas sound tempting, but the considerations for solar geoengineering have side effects. “Because of this sulfur layer, which is there globally, the sky would no longer be blue. So you would have to reckon with the fact that you always have a slightly milky sky and that would of course also have psychological effects on people, «says Niemeier. Another disadvantage: Nobody can predict with absolute certainty what consequences solar geoengineering will have on our climate. Should we dare such expensive and far-reaching interventions in nature despite uncertainties?
Should we darken the sun to save ourselves from climate collapse?
We are discussing this this week in the »Climate Report«, our podcast on the climate crisis.
Our guests are Ulrike Niemeier from the Max Planck Institute for Meteorology and Johannes Quaas, Professor of Theoretical Meteorology at the University of Leipzig.
Then you will now hear our »Climate Report«.