A new study and a new book claim that the worst global warming scenario will literally make the planet unsuitable for habitation.
The book is titled "The Unusual Land: Life After Warming" and is written by New York Journal Editor David Wallace-Wales; this is an extension of his controversial viral article, published in July 2017, with the same title. From February 26th, this is number 11 in Amazon's bestselling list, rare for any climate, but perhaps another sign of increasing interest in strong climate action.
The book published last week makes a drastic warming of 7 ° F (4 ° C) above pre-industrial temperatures to 2100 years, without dramatic climatic events, a world of ever-worsening meadows and an endless shortage of food.
Meanwhile, a new study, published Monday Tapios Schneider examines one of the ways that the worst case scenario could get worse.
The study looks at what happens if we triple atmospheric concentrations of CO2 to 1200 parts per million (ppm) from their current level of 410 ppm. This is unlikely, but it is still possible given the current emissions, especially if we trigger key feedback, such as the release of huge amounts of CO2 from the melting eternal frost in the Arctic.
In such a world, it can be expected to warm up to 11 ° F (6 ° C) or even 14.4 ° F (8 ° C). The new study found that, at 1,200 ppm, cloud-like cloud compartment clouds that help cool the planet "become unstable and disappear, triggering a global warming spike," which would add even more stunning 14.4 ° F 8 ° C) of global warming.
The study explains that cloud cover clouds "cover about 20% of the subtropical oceans," especially the eastern shores of California or Peru. These clouds "cool and overshadow the earth as they reflect the sunlight that brings them back into space."
Their loss is likely to cause total warming after 14 ° C, a truly uninhabitable land.
scenario may seem impossible, but it is worth noting that in the early Eocene, 52-56 million years ago, the Earth's temperature was in this range – both Arctic and Antarctic were free of ice – and the levels of CO2 in the air was only in fact, the study itself refers to the so-called "Orange Earth" millions of years ago, perhaps caused partly by the loss of layers of clouds – and that it can be repeated again. " in the future if CO2 levels continue to rise.
Study findings are only a glance at this dangerous feedback cycle, and some scientists say there is still work to be done to investigate the likelihood of this scenario. This is because climate models are complex, especially when it comes to clouds.
Commenting on the study, leading climate expert Michael Mann tells ThinkProgress in an e-mail that: "The findings are plausible. Tapio Schneider is not a scientist to be fired lightly. "But he noted that" Even if the findings are true (and this will require replication from several independent research teams), this threshold only hit 1,200 ppm CO2 in the atmosphere.
Finally, Mann warned (an initial accent): "We can not afford to get anywhere near 1200 ppm CO2."
And reaching levels of carbon dioxide far below this would have catastrophic consequences. He explained that only 7 ° F (4 ° C) of warming "would represent the end of civilization as we know it."
However, it may be difficult to fully understand the scale of warming when dealing with what it feels like abstract numbers. In fact, one of the Wallace-Wales points is that "because the numbers are so small, we tend to trivialize the differences between one degree of warming and two, two and four degrees." [Tttodowhatseemstrivialandabstractasconcreteandvisceralaspossiblesuchasheadlinessuchas"deathofheat""hunger""drowning""mildfire""airless""warmingulcers"collapse"and"Climateconflict"
And in the middle of the book, he says in all the plaques: "If you have come here, you are a brave reader." He admits that one of these chapters contains "enough." horror to trigger panic attack even in the most optimistic of those who are considering it. "
But, he adds, science makes it clear that" you're not just thinking about it; you are about to experience it. We are in many places. "
In recent years, science has highlighted two key facts that further support this point. Firstly, climate impacts that come from another Celsius degree of warming – for a total warming of 3.6 ° F (2 ° C) – will be catastrophic.
Second, the climate system has many feedback loops that threaten to accelerate warming if we trigger them.
A major 2018 survey by 16 top climate scientists, for example, concluded that if we warm the planet 2 ° C, it may be enough to trigger backward links that push the planet to the irreversible "Earth-conservatory ". This would mean a catastrophic warming of 5 ° C or more, with widespread dust bowls and a rapid rise in sea level.
As you describe it, science makes it increasingly clear that there are no rational species that will allow us to reach the level of warming. And that's what makes strong action over the next decade, as envisaged in proposals like the Green New Course, a moral imperative.