According to a new study, man is not only warming the Earth but also making the climate chaotic.
A new study paints a comprehensive and general picture of the full potential impact of human activity on the climate. And the picture is not very beautiful. Although the study does not present a complete simulation of a climate model, the authors of the study, according to scientists from the Department of Physics and Astronomy at the University of Porto in Portugal, outline where we are going if we do not limit climate change and uncontrolled use of fossil fuels. The Earth is periodically undergoing massive changes in climate patterns, moving from one steady state to another. These shifts are usually caused by external factors, such as changes in the Earth’s orbit or huge waves of volcanic activity.
However, previous research suggests that we are now entering a new phase driven by human activity. As people pump more and more coal into the atmosphere, we are creating a new anthropocene era, a period of man-made climate systems that our planet has never experienced before. In the new study, the researchers modeled the introduction of anthropocene as a phase transition. Most people know the phase transitions of materials, such as when an ice cube changes from a solid to a liquid, when it melts into water, or when water evaporates into a gas. However, phase transitions also occur in other systems. In this case, the system is the Earth’s climate. A given climate provides regular and predictable seasons and weather, and a phase shift in the climate results in a new pattern of seasons and weather.
When the climate goes through a phase transition, it means that there is a sudden and rapid change in patterns on Earth. If human activity causes a phase transition in the Earth’s climate, it means that we are causing a new series of weather patterns to form on the planet. How these patterns will look is one of the most pressing problems in climate science. Where is the Earth’s climate heading? It depends significantly on what exactly we do in the coming decades. A drastic reduction in CO2 emissions, for example, would lead to a different result than if we didn’t change anything, the researchers write in the study. To take into account the different trajectories and decisions that humanity can make, the researchers used a mathematical tool called a logistic map.
A logistic map is great for describing situations where some variable, such as the amount of carbon in the atmosphere, may increase but naturally reach a limit. Scientists, for example, often use a logistic map to describe animal populations. Animals can give birth continuously, increasing their numbers, but they reach a limit when they consume all the food in their environment (or their predators become too hungry and consume them). Our impact on the environment is clearly increasing, and this has been the case for more than a century. But researchers say it will reach the limit, of course. The human population, for example, can only grow to this size and engage in so many carbon-emitting activities, and pollution will sooner or later degrade the environment. At some point in the future, CO2 emissions will reach their maximum limit, and researchers have found that a logistics map can very well capture the future trajectory of CO2 emissions.
The researchers looked at how the human logistics map could evolve depending on various factors, such as our population, the introduction of low-carbon strategies, and better, more efficient technologies. Once they found out how human carbon emissions would evolve over time, this was used to study how the Earth’s climate would evolve during a man-controlled phase transition. At best, as soon as humanity reaches the limit of carbon emissions, the Earth’s climate will stabilize at a new, higher average temperature. This higher temperature is bad for humans overall because it continues to lead to higher sea levels and more extreme weather events. But at least it’s stable. The anthropocene is like previous climates, only warmer and will continue to have regular and repeatable weather patterns.
In the worst case, however, the researchers found that the Earth’s climate leads to chaos. To real, mathematical chaos. In a chaotic system, there is no equilibrium and no repeatable patterns. A chaotic climate would have wildly changing seasons from decade to decade (or even year to year). In some years we would experience sudden extreme weather events, while in other years the weather would be completely calm. Even the average temperature on Earth could fluctuate wildly, alternating between cooler and warmer periods in a relatively short period of time. It would be completely impossible to determine the direction in which the Earth’s climate is heading. Most worryingly, the researchers found that above a certain critical threshold temperature of the Earth’s atmosphere, a feedback cycle could begin where a chaotic outcome becomes inevitable. There are indications that we may have already crossed this turning point, but it is not too late to avert a climate catastrophe.