Harald Lesch acknowledges the existence of climate change

In a recently resurfaced video from 2001, astrophysicist Harald Lesch, who works at the Institute for Astronomy and Astrophysics at the Ludwig Maximilian University of Munich, issues a stark warning about the current climate crisis. The video, titled "Why do ice ages occur?" and originally broadcast on ARD Mediathek, has been making waves on YouTube, Facebook, and more recently, Instagram.

Lesch explains that we are currently living in an ice age, a geologically rare state in which ice masses persist at the poles. This definition is recognised by the European Space Agency (ESA) and the Federal Institute for Geosciences and Natural Resources. He emphasises that ice ages highlight the instability of Earth's climate and that even small changes in land distribution can trigger significant climate effects.

However, the video also contains a statement that has been misinterpreted. Lesch explains how ice ages occur and that we are currently in a warm phase within an ice age. Yet, he also warns that it should not get warmer on our planet, a statement made at 20:32 in the ZDF Terra X video. Lesch clarifies that this is not a contradiction, but rather a warning about the current temperature increase due to greenhouse gas emissions and the current climate crisis.

The alleged contradiction in the video is a misconception based on misleading edits. Astrophysicist Harald Lesch is often accused of changing his opinion on climate change, but this is not true. In the original video, Lesch explains that the climate change we are experiencing today is mainly caused by human activity, not natural factors like volcanic eruptions or changes in solar radiation.

The IPCC reports on climate change from 09 August 2021 are public sources for the article. Natural climate factors took hundreds or thousands of years for such temperature increases as we are experiencing now within a few decades, making the current climate crisis an unprecedented challenge.

In a more recent ZDF Terra X episode from 2023 about synthetic fuels (E-Fuels) and the transformation of the transport sector, Lesch warns that small changes in temperature can lead to catastrophic effects if they happened today, such as temperature changes of up to 14-15 degrees within ten years.

The video, now over two decades old, serves as a sobering reminder of the long-term consequences of climate change and the urgent need for action.