It may be generations before the true impact of climate change is felt. But some major, devastating changes may occur within decades -- and we're not prepared to deal with the fallout.
A rapid decline in Arctic sea ice and the extinction of plant and animal species are some of the "abrupt" changes we may say within our lifetimes, according to a new paper from the National Academy of Sciences. The Huffington Post reports:
Many such changes, according to Tony Barnosky, a professor in the Department of Integrative Biology at the University of California, Berkeley, are "things that people in this room will be around to see." He emphasized that scientists are "really worried about what's going to happen in the next several years or decades."
..Other, more gradually occurring changes can still have abrupt impacts on the ecosystem and human systems, such as the loss of fisheries or shifts in where certain crops can be cultivated. Rapid loss of ice, for example, would mean that sea levels rise at a much faster rate than the current trend, which would have a significant effect on coastal regions. A 3-foot rise in the seas is easier to prepare for if it happens on a 100-year horizon than if it happens within 30 years.
"If you think about gradual change, you can see where the road is and where you're going," said Barnosky. "With abrupt changes and effects, the road suddenly drops out from under you."
As Richard Alley of Pennsylvania State University, another of the report's authors, put it to The New York Times' Andrew Revkin, "Katrina’s high waters just made it over the levee, and the difference between 'just over' and 'not quite over' proved to be a lot of billions of dollars and human disruption."
The good news, on the other hand, is that some of the loudly touted risks of climate change are still far off in the future. Revkin sums up the effects that we're no longer likely to see before the end of this century:
- Disruption to Atlantic Meridional Overturning Circulation (the ocean current shifts that were caricatured in “The Day After Tomorrow“)
- Changes to patterns of climate variability (such as the Pacific temperature shifts (such as El Niño La Niña)
- Increasing release of carbon stored in soils and permafrost and methane from seabed methane hydrates
- Sea level rise from ice sheet destabilization
There's still a chance, then, that meaningful change, made now, can help mitigate those risks, or at least help us prepare for them. For the effects that can occur sooner, the researchers argue, an early warning system is needed -- lest we end up caught entirely off our guard.
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