Global crises challenge environmental science and biotechnology

In 1960, about 3 billion people lived on Earth. Forty years later, we were 6 billion, and by 2040 we might be as many as 9 billion. We are many, indeed; some assume that we are already too many with respect to the Earth system’s capacity to supply humanity with indispensable resources, and to regenerate and absorb the wastes we are generating. By the way: What is the bearing capacity of our planet? Is it 200 million people as Lovelock (2009) suggests, or 650 million proposed by and Gorshkov et al. (2000)? According to Wackernagel (WWF 2008) humanity used in 2008 the equivalent of 1.3 planets considering the resources we need or believe to need, and considering the waste we emit. However, as everybody knows, we have only one planet at our disposal. More people require additional energy, food and water. More land is also required for people to settle, to produce agricultural products including energy crops, to operate industrial installations and airports, and to permit road traffic. Turning to the back side of the coin, more people generate more solid, liquid and gaseous wastes, which are typically sent away and out of sight causing agricultural land, water bodies and the air to deteriorate in quality. This, in turn, aggravates supply of people with the required base of life, qualitatively and quantitatively alike. There is one additional factor to be considered. Increase of population density beyond a certain threshold bears the risk of societies to destabilize because individuals lose the territorial freedom they naturally claim. Like most other species on Earth, people get aggressive when a minimum of space around them is trespassed by strangers. Maternal protectiveness, territorial defense, egoism, greed and herd instinct are genetically encoded properties of human beings—transcribed to family networks, tribes, economic institutions and political systems. In conclusion, the primary problem we are facing is the rapid increase of the population density, globally as well as locally. We have to deal with a population density crisis, and we ought to find measures to handle this crisis. Derived from the population density crisis, we face a complex of secondary, widely interwoven crises such as the climate, water, food, poverty, social inequality and economy. Because all these sub-crises are interrelated, any attempt to solve a single sub-crisis cannot lead to a sustainable solution. It only might provide us with some time to relax. What we ought to do is to take a multi-dimensional interand trans-disciplinary approach taking into account local and regional peculiarities with respect to cultural heritage, religious concerns, and tribal traditions. Starting from top to bottom, we are supposed to make any attempt to minimize the impacts originating from densely populated areas, and their effects on the life enabling function of the ecosystems. The term Earth System P. A. Wilderer (&) Schliersee, Germany e-mail: peter.wilderer@mytum.de