The IPCC's climate science assessment concludes that humans are causing climate change and that it’s going to get worse. If this comprehensive report is what the Wall Street Journal editors consider to be a “flimsy intellectual framework,” it is unclear what they would ever consider certain enough to act on. In reality, a demand for complete certainty is the last excuse of those who court disaster by being unwilling to act, as the military knows all too well.
The following is a guest post by Climate Nexus (text in PDF format here):
Wall Street Journal Fails to Notice We’ve Seen the Hottest Decade Ever
The world’s scientific community came together last week to issue an updated assessment of climate science and reported that the evidence is clearer than ever that human influence is driving climate change. Ninety-five percent certain, in fact. But this report by the Intergovernmental Panel on Climate Change did not satisfy the editors of the Wall Street Journal, who called for delay in acting upon this science. They justify this argument by inviting us to look at the short-term view, in particular the short-term trend in the warming of surface temperatures.
This perspective conveniently ignores several key facts:
- The last decade (2001-2010) has been the hottest ever on record for surface temperatures, overpowering natural factors exerting a cooling influence.
- Warming in the oceans hasn’t slowed, and other impacts have accelerated – including Arctic ice melt, mass loss in ice sheets and glaciers, and a dramatic increase in heat waves around the world. Climate models have proven remarkably accurate when it comes to reproducing the long-term warming we’ve observed over the last half century, and were never expected to reproduce the exact timing of natural events.
- A warming of 1.5ºC by the end of the century, the minimum projected by the IPCC, would still be quite dangerous.
- The conclusions of the IPCC are far from “flimsy.” The group’s recent report represents the largest scientific consensus ever assembled.
We’ve just experienced the hottest decade ever recorded. Each of the last three decades has been successively hotter than any decade on record, despite natural variations (including “pauses”) in the rate of surface warming throughout this period. Furthermore, this hottest decade has happened at the same time as natural events that would ordinarily produce cooling. A record low solar minimum, aerosols from volcanic eruptions, and double La Niña events have all conspired to reduce global surface temperatures. The IPCC report assigns equal weight to these factors, expressing medium confidence in this finding primarily because we are not sure about the relative balance of these natural short-term factors. But surface warming hasn’t cooled or even stopped – merely slowed. Experts predict that once those natural cycles revert, it will jump up once more, as it has in the past.
Warming is continuing. The IPCC notes that the oceans absorb over 90% of all the heat reaching the Earth, and the atmosphere absorbs only 1%. The IPCC also notes that ocean warming has continued unabated. We don’t yet have precise enough measuring data to know whether ocean warming is accelerating, but it’s possible based on the other impacts we’re observing. Arctic sea ice is in a death spiral, and the melting of ice sheets and glaciers has accelerated as well. This melt, combined with thermal expansion of the warming oceans, has produced sea level rise at the upper end of model projections. The occurrence of heat waves has increased, with severe impacts on vulnerable human populations.
Climate models work. The Wall Street Journal editors focus on an overestimation of surface warming in the past 15 years, neglecting to discuss other impacts and time periods where models significantly underestimated the effects of climate change. Over the long term, these discrepancies average out, and the models have been remarkably accurate. In fact, the current discrepancy in surface warming that the WSJ fixates on cannot be called a failure, as the models were never designed to predict the exact timing of natural events like La Niñas and volcanic eruptions. Scientists remain confident in the models’ long-term future projections, and the data show their confidence is justified.
Even the lowest likely estimates are dangerous. The Journal doesn’t consider a degree or two of global warming to be significant, but this perspective misses the forest for the trees. It’s the impact of that warming that poses the threat. Looking at heat extremes, for example, the IPCC report notes that human influence has already doubled the occurrence of heat waves in some locations. And the residents of New York City would certainly disagree that warming to date has been inconsequential, as the destruction from Superstorm Sandy was made significantly worse by the higher sea level upon which the storm surge swept across parts of the city.
The IPCC’s recent report represents the largest scientific consensus ever assembled. It’s bigger and better even than the previous IPCC report, with 600 contributing authors citing 9,200 publications. If this is what the WSJ editors consider to be a “flimsy intellectual framework,” it is unclear what they would ever consider certain enough to print.
In reality, a demand for complete certainty is the last excuse of those who court disaster by being unwilling to act, as the military knows all too well. General Gordon Sullivan has noted about climate change: “We know a great deal, and even with that, there is still uncertainty. But the trend line is very clear. We never have 100 percent certainty. We never have it. If you wait until you have 100 percent certainty, something bad is going to happen on the battlefield.”
With their “wait and see” arguments about wealth and technological growth, the editors twist their logic beyond reason. The worst-case scenarios bring on as much temperature change as we've had since the last Ice Age. The World Bank estimates a worst-case scenario would cost the world economy $1 trillion a year. There would be no wealth to pay for coping if the global economic engine has been wrecked by catastrophic climate change.
The IPCC represents the entire world’s climate scientists in concluding that humans are causing climate change and that it’s going to get worse. If we wait until the Wall Street Journal’s impossible standards are satisfied before we act, it will be too late.
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Some earlier posts by Climate Nexus: