A report this week from the prestigious journal Nature
What does a “state shift” mean? Why is this relevant to the future? One reason is that the inability to conceive of a state shift resembles the inability to understand the kinds of exponential process happening today. A state shift is the point at which something – a material, a nation, the earth – reaches a tipping point and flips over into something radically different. Water turns into ice; peasants turn on the king; a protein folds.
State shifts in complex systems are difficult to predict, because the stages leading up to them are incremental. Until the last snowflake triggers it, nobody expects the avalanche. So, for example, watching water turn colder and colder isn’t going to give you an intuition about water turning into ice; or watching a person get old and wrinkly won’t teach you about death. There are transition points where an entity undergoes a radical shift; the caterpillar becomes a butterfly; the permafrost melts and releases huge amounts of carbon; or the French Revolution convulses a country and the world.
Such transitions have been studied in small settings – a meadow, lake, forest. The science of looking at critical transitions for the planet is in its infancy – the tools for studying systems of such complexity are still developing – but the authors here conclude that there is a very real urgency to the problem. Once a system tips, it may be difficult for it to return to its previous state, or in the case of the ecosystem, take thousands or millions of years. This is another reason that we have trouble conceiving of these phenomena: the human mind isn’t well suited to thinking in such long time spans.
Their conclusion is sobering: the world we know – the forests, tundra, all the things great and small that grow and crawl – may within a few decades, the lifetime of every one of us, change dramatically. The term “anthropocene” is used more and more; it means a period when the main factor changing the earth is humanity – not volcanoes, or ice sheets, or asteroids. Through our use of land, energy, and other species we are already “geoengineering” the world – only not deliberately, and definitely not beneficially.
“Comparison of the present extent of planetary change with that characterizing past global-scale state shifts, and the enormous global forcings we continue to exert, suggests that another global-scale state shift is highly plausible within decades to centuries, if it has not already been initiated. As a result, the biological resources we take for granted at present may be subject to rapid and unpredictable transformations within a few human generations.”