Humans aren’t just warming the Earth, they’re making the climate chaotic, a stark new study suggests.
The new research, which was published on April 21 in the Preprint Database arXiv (opens in a new tab), paints a broad and general picture of the total potential impact of human activity on the climate. And the picture is not pretty.
Although the study does not present a complete simulation of a climate model, it does give a general overview of the direction we are heading if we do not restrict climate change and our uncontrolled use of fossil fuels, according to the study’s authors, scientists from the Department of Physics and Astronomy at the University of Porto in Portugal. .
“The implications of climate change are well known (droughts, heat waves, extreme events, etc.),” researcher Orfeu Bertolami told Live Science in an email. “If the Earth system enters the region of chaotic behavior, we will lose all hope of solving the problem somehow.”
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The Earth periodically experiences massive shifts in weather patterns, shifting from one stable equilibrium to another. These changes are usually driven by external factors such as changes in Earth’s orbit or a massive increase in volcanic activity. But previous research suggests that we are now entering a new phase, one driven by human activity. As humans pump more carbon into the atmosphere, we are creating a new Anthropocene Era, a period of human-influenced climate systems, something our planet has never experienced before.
In the new study, the researchers modeled the introduction of the Anthropocene as a phase transition. Most people are familiar with phase transitions in materials, such as when an ice cube changes from a solid to a liquid by melting in water, or when water evaporates into a gas. But phase transitions also occur in other systems. In this case, the system is the Earth’s climate. A given climate allows regular and predictable flows seasons and weather, and a phase transition in climate leads to a new pattern of seasons and weather. When the climate goes through a phase transition, it means the Earth is experiencing a sudden and rapid change in patterns.
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If human activity is causing a phase transition in the Earth’s climate, it means we are causing the planet to develop a new set of weather patterns. What those models will look like is one of the most pressing issues in climate science.
Where is the Earth’s climate going? Much depends on what exactly our business will be over the next few decades. Drastically reducing carbon production, for example, would lead to different results than changing nothing at all, the researchers wrote in the study.
To account for the different trajectories and choices humanity could make, the researchers used a mathematical tool called a logistics map. The logistic map is excellent for describing situations where certain variables – such as the amount of carbon in the atmosphere – may grow but naturally reach a limit. For example, scientists often use the logistic map to describe animal populations: animals may continue to give birth, increasing their numbers, but they reach a limit when they consume all the food in their environment (or their predators have too much hunger and consume them).
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Our influence on the environment is definitely growing, and has been for more than a century. But it will naturally reach a limit, according to the researchers. For example, the human population can only grow to a certain point and can only have a certain number of carbon-emitting activities; and pollution will eventually degrade the environment. At some point in the future, carbon production will reach an upper limit, and the researchers found that a logistic map can capture the future trajectory of this carbon production very well.
Everything is mess
The researchers explored different ways in which the human logistics map could evolve, depending on various factors such as our population, the introduction of carbon reduction strategies and better and more efficient technologies. Once they found how human carbon production would change over time, they used it to examine how Earth’s climate would change through the human-induced phase transition.
In the best-case scenario, once humanity reaches the carbon production limit, Earth’s climate stabilizes at a new, higher average temperature. This higher temperature is bad for humans overall, as it always leads to sea level rise and more extreme weather events. But at least it’s stable: the Anthropocene looks like previous climatic ages, only warmer, and it will still have regular, repeatable weather patterns.
But in the worst-case scenario, the researchers found that Earth’s climate led to chaos. True, mathematical chaos. In a chaotic system, there is no equilibrium and no repeatable patterns. A chaotic climate would have seasons that change wildly from decade to decade (or even year to year). Some years would experience sudden flashes of extreme weather, while others would be completely calm. Even the Earth’s average temperature can fluctuate wildly, going from colder periods to warmer periods over relatively short periods of time. It would become quite impossible to determine in which direction the Earth’s climate is heading.
“Chaotic behavior means that it will be impossible to predict how the Earth system will behave in the future, even though we know with high certainty its current state,” Bertolami said. “This will mean that any ability to control and drive the Earth system towards a state of equilibrium that promotes the habitability of the biosphere will be lost.”
More worryingly, the researchers found that above a certain critical temperature threshold for Earth’s atmosphere, a feedback cycle can kick in where a chaotic outcome would become unavoidable. There are signs that we may already be past this tipping point, but it’s not too late to avert climate catastrophe.
Originally posted on Live Science.