It’s easy to visualize a world with 7.5 billion people – that’s the world we live in today. It’s also easy to visualize a world that has become completely hostile to human life with no possible survivors due to anthropogenic warming. Think “Venus.” Most climate models suggest plausible scenarios that eventually lead to conditions that will not support human life on earth.
But what’s much more difficult to visualize is the progression, the process, the day-by-day timeline, that takes us from 7.5 billion people to zero. Climate experts David Spratt and Ian Dunlop have laid out one gruesome but not unlikely scenario that goes there if we continue on our current path. And within the lifetime of most people alive today.
The authors describe a decade by decade timeline that relates one plausible scenario of our continued greenhouse gas generation and concomitant temperature rise to changes in conditions on earth. Assuming the current inadequate response to the climate crisis, they describe an earth characterized by severe weather events, floods, fires, species extinctions, droughts, sea-level rise, plagues, agricultural failures, and related disasters by the year 2050, which would result in irreversible changes in earth’s ecosystems, billions of displaced climate refugees, resource wars, and even a potentially uninhabitable planet.
Thirty-five percent of the global land area, and 55 percent of the global population, are subject to more than 20 days a year of lethal heat conditions, beyond the threshold of human survivability. . . Aridification emerges over more than 30 percent of the world’s land surface. Desertification is severe in southern Africa, the southern Mediterranean, west Asia, the Middle East, inland Australia and across the south-western United States.
And the 3 decades in between will be no walk in the park either.
The report points out that climate projections have consistently underestimated the speed of climate change over the past 40 years. While the scenario they describe is severe, it is not implausible, they claim,
due to the activation of a number of carbon-cycle feedbacks and higher levels of ice albedo and cloud feedbacks than current models assume.
Is there hope? Some impacts are unavoidable.
By 2050, there is broad scientific acceptance that system tipping-points for the West Antarctic Ice Sheet and a sea-ice-free Arctic summer were passed well before 1.5°C of warming, for the Greenland Ice Sheet well before 2°C, and for widespread permafrost loss and large-scale Amazon drought and dieback by 2.5°C.
Perhaps, if our collective behavior changes abruptly, the impacts of the coming crisis can be mitigated and possibly even managed. But to avoid the doomsday scenario, we must take drastic and immediate steps.
The entire report is short (less than 12 pages) and is available to download at the above link. It’s a horrifying but essential read.