A doomsday ending to climate change isn't inevitable, but the situation is becoming even more desperate. Without immediate and drastic action, reminiscent of efforts during World War II, a new analysis estimates that by 2050, climate change could become an "existential threat to human civilization" which can never be undone.
This 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, that found that climate models frequently underestimate the most extreme scenarios.
Endorsed by former Australian defense chief Admiral Chris Barrie, the message is simple: unless we take climate action in the next thirty years, it is entirely plausible that the planet warms by 3°C and that human civilization as we know it collapses.
Under this scenario, the world will be locked into a "hothouse Earth" scenario, where 35% of the global land area, and 55% of the global population, will be subject to over 20 days per year of "lethal heat conditions, beyond the threshold of human survivability."
Ecosystems will collapse, including the Amazon rainforest, coral reefs, and the Arctic. North America will suffer from devastating wildfires, heat waves, and drought. The great rivers of Asia will be severely reduced as will water availability right around the world, affecting roughly two billion people.
Lower likelihood events at the high end of the probability distribution have the highest risk, the authors say (RT Sutton/E Hawkins)
Rainfall in Mexico and Central America will fall by half and agriculture will be nonviable in the dry subtropics. Semi-permanent El Nino conditions will prevail, and deadly heat waves will persist in some areas for over 100 days a year. Over a billion people will be displaced.
According to the authors, the only solution is a revolutionary, global zero-carbon energy, industrial, and economic strategy, focused less on climate models and more on extreme scenario planning. As the report explains:
"To reduce this risk and protect human civilization, a massive global mobilization of resources is needed in the coming decade to build a zero-emissions industrial system and set in train the restoration of a safe climate."
Even though climate models are useful for research, the paper argues that these tools often err on the side of caution and focus on middle-of-the-road outcomes. By ignoring the high-end possibilities, we are therefore ill-prepared for an unexpected catastrophic event, one which we should have seen coming.
That may sound overly dramatic or alarmist, but the probability of that 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 which 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 that, climate change won't present as a normal distribution but instead will be skewed by a fat tail – indicating a higher likelihood of warming which is well in excess of average climate models.
As the authors explain under a business-as-usual scenario, warming is set to reach 2.4°C by 2050. However, if feedback cycles are taken into account, there might be another 0.6°C that current models do not assume.
The Breakthrough National Centre has published the policy paper for Climate Restoration.
Reference: Science Alert
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