Confirming the obvious to anyone who’s been watching the world’s weather go haywire, Nature has published a pair of articles that link greenhouse pollution to killer weather disasters. In “Human contribution to more-intense precipitation extremes,” researchers in Canada and Scotland found that carbon pollution “contributed to the observed intensification of heavy precipitation events” in the northern hemisphere from 1950 to 1999:
Our results provide to our knowledge the first formal identification of a human contribution to the observed intensification of extreme precipitation.
The scientists — Seung-Ki Min, Xuebin Zhang, and Francis W. Zwiers of Environment Canada and Gabriele C. Hegerl of the University of Edinburgh — modeled the influence of global warming pollution on maximum one-day and five-day precipitation events, and found the strong fingerprint that the probability of intense precipitation on any given day has increased by 7 percent over the last 50 years.
The second paper, “Anthropogenic greenhouse gas contribution to flood risk in England and Wales in autumn 2000,” used a different kind of modeling to determine the influence of climate pollution on the catastrophic floods that rocked Great Britain in 2000. They relied on the distributed computing project climateprediction.net to run thousands of iterations of scenarios with and without greenhouse pollution, finding a strong influence:
Here we present a multi-step, physically based ‘probabilistic event attribution’ framework showing that it is very likely that global anthropogenic greenhouse gas emissions substantially increased the risk of flood occurrence in England and Wales in autumn 2000.
Essentially, the authors — Pardeep Pall,Tolu Aina, Dáithí A. Stone, Peter A. Stott, Toru Nozawa, Arno G. J. Hilberts, Dag Lohmann, and Myles R. Allen — found that global warming approximately doubled the risk of flooding. Expressed differently, about 70 percent of the risk of flooding was attributable to greenhouse pollution, with a high degree of confidence that at least 20 percent of the risk was attributable. In laymans’ terms, burning oil and coal caused England to flood. Finally, a decade after the $5 billion floods devastated the United Kingdom, scientists have provided the analysis that demonstrates greenhouse pollution is a cause:
By demonstrating the contribution of such emissions to the risk of a damaging event, our approach could prove a useful tool for evidence-based climate change adaptation policy.
Neither study has looked at the last decade of climate, the hottest and wettest on record — including unprecedented, catastrophic floods and storms on every continent (even Antarctica).
“This has immense importance not just as a further justification for emissions reduction, but also for adaptation planning,” says Michael Oppenheimer, a climate-policy researcher at Princeton University in New Jersey, who was not involved in the studies, told Nature.
“They should help lay to rest the myth that human-caused global warming will contribute to grievous harm only in some far-off future,” Joe Romm comments.
One also has to wonder how much longer the oil and coal companies will avoid liability for their decades-long campaign to lie about the threat of global warming and prevent action to protect humanity.