In the global warming debate, a widely employed argument is that climate change is a complex issue, that
there are still many variables and unknowns here. But why is this an argument to be skeptical about global warming? What we do not know might be an even more alarming picture...
OK, the issue is whether we have to force ourselves and all civilization to change policies and habits. Hence the standard is not of scientific curiosity, but of lawyers' scrutiny. Yet, concerned people have the right to insist that the "everything-will-be-all-right-at-the-end" hypotheses deserve just as much scrutiny.
What is most striking in the current "rational" debate, is that warming skeptics tend to present their arguments and hypothesis by completely ignoring the most basic facts of the "consensus" theory. Yeah, you can build rudimental theories about alternative influences (and this is very welcome). But you must acknowledge how strong the alternative theories are in objective comparison with the consensus theory. The scientific comparison starts with acknowledging the basic facts of competing theories. But skeptics seem to be just glad to skip the basic alarming facts.
In my opinion, everyone must know the following two basic facts:
- In the last 150 years, the CO2 concentration rose from 280ppm to 380ppm.
- In the preceding 400 millenia (at least), the maximum CO2 concentration was about 300pm.
The numbers have certain margin of error, but they are widely accepted (or ignored). The chance is really negligible that the following pictures are fundamentally wrong:
Of course, I implicitly suggest the following two facts as well:
- The recent increase of CO2 concentration is due to the industrial human activity.
- Variations in CO2 concentration and climate change are closely related.
There is basically no controversy about these facts. For instance, the long-term graphs as above [obtained from ice cores or ocean sediments] show that large scale temperature variations go remarkably much in synch with CO2 (and methane!) concentration variations.
The precise casual link between CO2 concentration and climate is disputable. But available data strongly suggests that there exist runaway effects when increased temperature causes larger CO2/methane concentrations and vice versa. With runaway scenarios, it hardly matters which parameter increased first. It is better to stay away.
For example, two graphs above show that the global temperature and CO2 concentration typically decrease slowly, whereas their increases can be very steep. This observation has only pessimistic interpretations so far. In particular, massive forest fires and methane instability in oceans are suspected.
Compared with the above facts and interpretations, the skeptical theories are based on must shaker or less impressive grounds. For example, you can only "hopefully" suspect that the medieval warmings and "mini ice ages" were as substantial as the current climate change. Regarding the Sun spot activity, essentially we have no historical data to conclude anything; neither suspicions of its relative significance are strongly based. And by the way, the Sun activity is very low at the moment. Last month I visited an observatory for a couple of days, and there was nothing to observe on the Sun - it was just a homogeneous disk.
In this climate debate, one cannot ignore the strongest facts. Somehow, such facts are always on the warming side. One more fact to consider:
- The CO2 concentration is still increasing.
It is a safe guess that even the rate of CO2 buildup is increasing, just as human activity. We may argue which CO2 concentrations we may comfortably allow, but sooner or later we
have to stabilize CO2 concentration. And we must learn how to reach agreement throughout the globe, and how to change the behavior. We better start learning now.