The National Wildlife Federation released a report last week that began:
Overwhelming scientific evidence supports reducing carbon pollution* that causes global warming as much as possible and as quickly as possible.
Why such a stark verdict? Because…
Global warming is happening faster than predicted even several years ago, with many natural systems already seriously impacted.
This is an odd contention given that we are now in a multi-year period (12 years and counting) period during which time the global warming has been preceding much more slowly than the climate-model mean projections of the expected rate of temperature rise. And, what’s even worse (for the models anyway), is that the rate has now dipped near the lower bound of the 95% confidence range of model projections. If the slowdown continues much longer, it will be a clear indication that something is amiss with the temperature projections—and thus with alarming claims that depend upon them.
But the NWF is apparently undaunted by the temperature behavior (and its implications) in the real world and goes on to provide a litany of woe:
Sea-level rise by the end of the century may be two to three times previous projections. Arctic sea ice is melting faster than anticipated even a few years ago. Northern forests are under attack from heat, drought, insects, and fires. And, many of the changes in our climate may be with us for hundreds and thousands of years.
Which inevitably leads into a call for drastic and dramatic actions to restrict greenhouse gas emissions:
Congress must heed the scientific evidence of global warming and take effective action to minimize its extent and impacts as soon as possible. With emissions of CO2 continuing to rapidly increase, and the consequences of warming adding up, action is needed now. Scientific information should play a prominent and explicit role in the design of global warming legislation, especially in determining the caps for CO<sub>2</sub> emissions.
And finally, the NWF concludes its scare-and-regulate diatribe with the following proposal:
An explicit process for periodically reviewing the science and adjusting emission caps as needed is essential. As we learn more about how the climate system is responding to added carbon dioxide and other greenhouse gases in the atmosphere, and possibly confront unanticipated abrupt climate changes, it will be critical to have the ability to adjust the caps accordingly. Scientific reviews should be mandated about every 5-10 years and the Administration should be required to respond with revised emissions reduction targets or a clear rationale for keeping the existing caps.
An interesting idea: A periodic review of the evolution of the earth’s climate and a revisitation of greenhouse gas emissions caps.
This is precisely the type of thing that my colleague Ross McKitrick at the University of Guelph (Ontario) has been floating for a while now to anyone who will listen.
Ross’s idea is to establish an agreed upon metric that climate models identify as reflecting the strength of greenhouse gas-induced warming (such as the mean temperature of the tropical troposphere). Then use some multi-year average of that index to control emissions policies accordingly. The most direct version, which he calls the ‘T3? tax (for temperature of the tropical troposphere) involves tying a carbon tax to the satellite-measured average temperature of the area of the troposphere models point to as especially sensitive to changing greenhouse gas levels. In a variation proposed in House testimony last summer, he suggested that the emissions limit in a cap-and-trade system be similarly calibrated. If rapid warming occurs, the cap tightens relatively faster; if no warming is observed, the cap stays loose and the permits stay cheap or even free.
A third, and even simpler, option is what Ross calls the “self-destruct clause.” Agree on some minimum objective measure of warming that would have to be observed by 2015 and/or 2020 to confirm global warming as a tangible problem worth addressing. Write into the legislation a provision that if that threshold isn’t met, the entire policy is revoked. Of course the indicator would have to be based on a transparent, valid, and meaningful data set, and agreement would have to be reached on the threshold. Even putting such matters onto the table would spark some revealing discussions about how complex and uncertain the issue remains. One can anticipate the difficulty of alarmists like the NWF once they see that endorsing their own rhetoric implies supporting a high threshold.
If such basic questions of measurement and minimum thresholds cannot be answered, then it would be hard to argue there has been enough resolution of uncertainty to justify any policy. If the basic questions can be answered, then as Ross puts it, there is no reason why any regulating body should object to a self-destruct clause being added to any legislation aimed at climate change mitigation. If the regulators (and their supporters) understand and believe their own global warming rhetoric, all sides should welcome it equally.
Clearly, there are still some details that would have to be worked out—the impact of natural variability on the index values, assurances that the periodic reviews weren’t later amended once the initial regulations were passed, etc. But at the very least, Ross should be glad to see that his idea is gaining traction—even among the alarmists (although I doubt this is what the NWF had in mind).
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* This usage of “carbon pollution” is quite puzzling. Carbon dioxide doesn’t become directly harmful to humans until a concentration of somewhere above about 10,000 ppm (currently we are at 385 ppm), so this is not the problem. Instead, it is the indirect (climate) impacts of enhancing CO<sub>2</sub> concentrations that have some folks (like the NWF and the EPA) worried. But, ironically, too little CO<sub>2</sub> in the atmosphere is far worse than increasing CO<sub>2</sub> amounts. If carbon dioxide levels in the atmosphere get too low, the earth would start to cool towards another ice age—a climate change with far more detrimental impact than a warming. So it takes a twisted definition of “pollutant” to describe a substance that is worse in its absence than in its presence. Imagine if the shoe were on the other foot and human activities were removing CO<sub>2</sub> from the atmosphere and the specter of an ice age loomed. Would the Clean Air Act apply then? Or would it be redrafted into the Too-Clean Air Act?