2. What is the theory of the nine limits of the planet and what does it have to do with the Anthropocene?
The scientists Johan Rockström of Sweden and Will Steffen of the United States grouped a series of data obtained by researchers in different countries and times. Using this material, in a joint work with scientists from the Stockholm Resilience Center, in 2009 and 2015 they drew up “a list with nine limits of the planet that would be extremely dangerous to pass, which has already occurred in the case of four of them”, according to a UNESCOs report. These four limits are: the climate, the alteration of the vegetal cover, the extinction of animal species and the alteration of the biogeochemical flows, in which the cycles of phosphorus and nitrogen play an essential role.
The other five borders of the Earth correspond to: consumption of primary resources, energy use, population growth, economic activity and deterioration of the biosphere. According to that report, since the Second World War these limits have soared that some have called it the “time of great acceleration”. Others even speak of “hyper acceleration” initiated in the 1970s. All these trends have been described as “unsustainable”.
Despite all this, and the indisputable human responsibility, as in the case of the increase in CO2, measurable in PPM, parts per million in the atmosphere, which has climbed from 300PPM to 400PPM in a few centuries, geologists think that the name Anthropocene It still does not comply with the traditional nomenclature of stratigraphy as to be defined as a new geological epoch.