(ABC NEWS) — Climate change represents “a near-to midterm existential threat to human civilization,according to an analysis by the Breakthrough National Centre for Climate Restoration.
The paper, published by the Australian think tank last week, gives one scenario in which by 2050 “accelerating climate-change impacts pose large negative consequences which might not be undone for centuries.”
If policymakers fail to act on evidence presented in the current Paris Agreement, in which global human-caused greenhouse emissions will not peak until 2030, this will lock in about 3 degrees Celsius of warming, according to the scenario presented in the report.
There is “broad scientific acceptance” that tipping points for the West Antarctic Ice Sheet and the seat-ice-free Arctic summer will pass well before 1.5 degrees Celsius of warming, according to the report. The Greenland Ice Sheet will melt well before 2 degrees Celsius of warming, and a widespread permafrost loss and large-scale drought in the Amazon will occur by 2.5 degrees of warming.
Even with 2 degrees Celsius of warming, there is a “high likelihood of human civilization coming to an end,” according to the report.
The continued warming trend will have adverse effects on the environment. While sea levels are expected to rise .5 meters, or more than 1.5 feet, by 2050, they will continue to rise another 2 to 3 meters by 2100.
The warming will also bring more than 20 days annually of “lethal heat conditions, beyond the threshold of human survivability, scientists report. Deadly heat conditions will persist for more than 100 days a year in west Africa, tropical South America, the Middle East and southeast Asia, which will displace more than a billion people from those areas.
The destabilization of the jet stream will significantly affect the intensity and geographical distribution of monsoons in Asia and west Africa and bring more extreme devastating weather, including wildfires, heatwaves, drought and inundation, to North America.
A number of ecosystems will collapse as well, including coral reef systems and the Amazon rain forest, and water supplies will sharply decrease in the most affected regions at lower latitudes, including the dry tropics and subtropics. This will make agriculture nominal in those areas, affecting 2 billion people worldwide.
Most regions in the world will see a significant drop in food production due to the adverse environmental effects, causing prices to skyrocket and leaving an inadequate amount of food to feed the global population.
“Massive nonlinear events in the global environment give rise to massive linear societal events,” the report states. “In this scenario, nations around the world will be overwhelmed by the scale of change and pandemic disease.”
The only way to avoid these results and restore the world to a safe climate would be “akin in scale to the World War II emergency mobilization” that would include implementing a zero-emissions industrial system “very quickly,” according to the analysis.
“Climate change now represents a near- to mid-term existential threat to human civilization,” the report states.