I realize most readers of Our Gallant Ship may not want to read all of the following scientific paper, but they may want to read the introduction and conclusion. I offer three quotes from Trajectories of the Earth System in the Anthropocene, PNAS, 2018, Will Steffen, Johan Rockström, Katherine Richardson, Timothy M. Lenton, et al:
“We explore the risk that self-reinforcing feedbacks could push the Earth System toward a planetary threshold that, if crossed, could prevent stabilization of the climate at intermediate temperature rises and cause continued warming on a “Hothouse Earth” pathway even as human emissions are reduced. Crossing the threshold would lead to a much higher global average temperature than any interglacial in the past 1.2 million years and to sea levels significantly higher than at any time in the Holocene.”
“This suggests that the risk of tipping cascades could be significant at a 2 °C temperature rise and could increase sharply beyond that point. We argue that a planetary threshold in the Earth System could exist at a temperature rise as low as 2 °C above preindustrial.” (my emphasis)
“We suggest that a deep transformation based on a fundamental reorientation of human values, equity, behavior, institutions, economies, and technologies is required. Even so, the pathway toward Stabilized Earth will involve considerable changes to the structure and functioning of the Earth System, suggesting that resilience-building strategies be given much higher priority than at present in decision making.”
paper was published by PNAS, the Proceedings of the National Academy
of Sciences, USA. PNAS strives to publish only the highest quality
scientific research, and papers undergo rigorous peer review and
approval by an NAS member before publication.
to Nick Garland for pointing me to this paper.
Properties will not be the only things to flood. Roads, bridges, power plants, airports, ports, public buildings, military bases, and other critical infrastructure along the coast also face the risk of chronic inundation. The direct costs of replacing, repairing, strengthening, or relocating infrastructure are not captured in our analysis, nor do we account for the indirect costs of flooded infrastructure, including disruptions to commerce and daily life (Neumann, Price, and Chinowsky 2015; NCA 2014; Ayyub and Kearney 2012). Taken together, these costs of chronic flooding of our coastal built environment—both property and infrastructure—could have staggering economic impacts.
According to an article in the Guardian, “Global temperatures in 2018 were the fourth warmest on record, US government scientists have confirmed, adding to a stretch of five years that are now collectively the hottest period since modern measurements began.”
“The Earth has taken a walloping since 2014,” said Brenda Ekwurzel, director of climate science at the Union of Concerned Scientists. “Eighteen of the 19 warmest years since record keeping began have occurred since 2001. That means kids graduating from high school have only known a world of record-breaking temperatures.”
“…it is a cliff that once you cross, you trigger a rockslide or an avalanche that brings ruin quickly.”
We are pushing the planet toward an irreversible “Hothouse Earth” — catastrophic warming of 9°F (5°C) or more with sea level rise of up to 200 feet — the study warns. And we may be much closer to the “point of no return” than most people realize. Read more…