A distressing Australian climate change analysis has some bad news: human civilization is set out to collapse by 2050 if don’t grapple with the imminent threat of climate change.
The new report, co-written by a former executive in the fossil fuel industry, is a harrowing follow-up to the Breakthrough National Centre for Climate Restoration’s 2018 paper, which found that climate models often underestimate the most extreme scenarios.
The authors argue we are now in a unique situation with no precise historical equivalent, with temperatures unlike anything humanity has ever experienced, and a population of nearly 8 billion people. This requires us to work towards avoiding catastrophic possibilities rather than looking at probabilities, as learning from mistakes is not an option when it comes to existential risks.
Under this scenario, the authors explain, the world will be locked into a “hothouse Earth” scenario, where 35 percent of the global land area, and 55 percent of the global population, will be subject to more than 20 days a year of “lethal heat conditions, beyond the threshold of human survivability.”
Governments fail to act on the evidence that the Paris Agreement isn’t enough to keep Earth’s temperature from rising, and will “lock in at least 3°C of warming”. As projected by previous studies, carbon dioxide levels have reached 437 parts per million, which hasn’t been seen in the last 20 million years. The planet warms by 1.6°C (2.8°F).
Emissions peak in 2030 and are reduced. However, carbon cycle feedbacks and the continued use of fossil fuels see temperatures rise by 3°C (5.4°F) by 2050.
By 2050 there’s a scientific consensus that we reached the tipping point for ice sheets in Greenland and the West Antarctic well before 2°C (3.6°F) of warming, and for widespread permafrost at 2.5°C (4.5°F).
This might sound overly dramatic or alarmist, but the probability of this happening is likely higher than we think.
Most climate models today are conservative and do not take into account tipping points and positive feedback loops that could amplify warming, like the release of greenhouse gases from thawing permafrost, the loss of West Antarctic glaciers, and reduced ocean and terrestrial CO2 removal from the atmosphere.
With a runaway event like this, climate change will not present as a normal distribution, but instead will be skewed by a fat tail – indicating a greater likelihood of warming that is well in excess of average climate models.
The policy paper is published by the Breakthrough National Centre for Climate Restoration.