2. Why he wants to prevent global warming

Reintegration of Germany

In 1989, just before the age of 40, Hans got promoted to professor at the University of Oldenburg, he faced a significant turning point. It was also a turning point for the world and an unpredicted event. West and East Germany were unified.

When the Berlin Wall was torn down, Professor Schellnhuber was in England. He had not seen the news for a while and learned about the wall on the airplane flying back to Germany. The newspaper posted a picture on the front page of people dancing on the Berlin Wall. At first, he could not understand what had happened. He thought it had to be a hoax, but it was true.

The Fall of the Berlin Wall

The Fall of the Berlin Wall

The unification of East and West Germany came as a pleasant surprise to the world. After being separated for decades following the war, Germany again became one country in which people were free to come and go as they pleased, and this changed Germany in fundamental ways.
The change influenced the scientific world too. Scientific associations and institutions in former East Germany were reorganized. The German government believed that if they were going to reform the organizations, they should create utterly new research institutes, for example, an institute devoted to the study of climate change.

Global warming

Before going into the details of global warming, let's take a quick look at what global warming is in general.
In the earth's 4.6 billion-year history, there have been periods when the climate has been much warmer or colder than it is now. The earth's climate has repeatedly changed over this long span of time.
It was about 10,000 years ago when the last ice age ended, and people were thought to have started farming soon after. Without the change in climate that the end of the ice age brought, humans would not have advanced to their current level.

However, in the past 100 years, the temperature of the earth has increased at an unprecedented pace. The reason is the growing concentration of greenhouse gases, carbon dioxide, and methane, in the atmosphere. These gases absorb heat and maintain the temperature at a certain level, much like a greenhouse does; however, when the concentration of these gases increases too much, the temperature also rises.
Human activity causes this rapid increase of greenhouse gases. Since the industrial revolution in the late 18th century, industrialization has advanced globally; and this has resulted in the increasing use of coal and petroleum. The consumption of such fossil fuels creates a massive amount of carbon dioxide, and the rate has continued to increase.

Now the research efforts clarified above mentioned. , but it wasn't around 1990. In the 1980s, the world just began to recognize the issue of global warming. Even as late as the 1990's, the global warming stayed as the puzzlling problem for the scientific community. In 1988, the Intergovernmental Panel on Climate Change (IPCC) was established to gather together the knowledge gained by researchers and provide the world with a scientific view of climate change and its impact. It was immediately before the reunification of Germany.

Supporting this, the reunified Germany also agreed on the need to establish an institution to research the impact of climate change. In 1993, the Potsdam Institute of Research (PIK) was established in Potsdam, which was in former East Germany.

The PIK seen from the air

The PIK seen from the air

Professor Schellnhuber assumed the position of Director of the PIK.
Around that time, he was conducting research on ecosystems in tidelands and the rise in sea level utilizing chaos theory. People said that Professor Schellnhuber paid attention as a young researcher to working on nature employing an entirely new method, and believed that he would be able to take initiative in promoting research on climate change. He attracted attention as a young researcher working on nature employing an entirely new method. People believed that Professor Schellnhuber would be able to take the initiative in promoting research on climate change.
Professor Schellnhuber decided to become the Director of the PIK because he knew the potential of climate change research.

What to consider first

When the PIK was established, they were investigating what would happen to the earth by the year 2100 if the temperature increases by 4 degrees C, what the impact on forests, agriculture, and water sources would be. They thought it would change wheat production by xx%, or that the spread of malaria would expand by xx%. They focused on predicting the impact of climate change.
For Professor Schellnhuber, such research was tedious, and he even thought that such research was not leading them in the right direction. He thought there were more important things to consider.

Why do we focus on preventing global warming? We do so because it is vital for life, and we want to avoid things that threaten our safety.
He thought we needed first to consider the risks we might encounter and that it was necessary to clarify the threats to human life.

To restrain global warming, we need to minimize greenhouse gas emissions, and we have to reduce our use of fossil fuels as much as possible. However, it is difficult to reduce our dependence on fossil fuels after having grown used to their benefits. To convince people around the world to address global warming, he thought he would need to clarify precisely what we would have to avoid.

Professor Schellnhuber believed that the PIK should conduct comprehensive studies to clarify how climate change occurs, what impact climate change would have, and what people should do about it.

The earth has a system with mutual interactions among the subatmosphere, ocean, crust, biological spheres (ecosystems) and the anthropogenic society, which is called the Earth System. Professor Schellnhuber attempted to clarify the mechanisms of climate change by analyzing the Earth System.
Since natural phenomena follow the laws of physics, Professor Schellnhuber used the computer to create simulations of these phenomena. Using these, he could reproduce climate change that had occurred in the past and simulate future temperature increase and its impact based on the assumption that carbon dioxide would continue increasing at the current rate.

For years, Professor Schellnhuber worked to clarify complex and unpredictable natural phenomena. While he was uniquely qualified to take the lead in this, such research required knowledge from a variety of fields such as the natural and social sciences as well as physics. Professor Schellnhuber approached his work by gathering researchers at the PIK specializing in these wide-ranging fields.

A computer simulation created at the PIK.

A computer simulation created at the PIK. Reproducing the oceanic currents is possible.

3. What we must avoid


Prof. Hans J. Schellnhuber