In view of the increasing debate on the topic of climate change in this country, I believe that now is a good time to reflect on the official position of our nation's premier scientific organization - the National Academy of Sciences.
The Academy was established by an Act of Congress, and approved by President Abraham Lincoln, in 1863. It's charter is to "investigate, examine, experiment, and report upon any subject of science or art" whenever called upon to do so by any department of the government.
Today, the Academy includes "approximately 2,100 members and 380 foreign associates, of whom nearly 200 have won Nobel Prizes. Members and foreign associates of the Academy are elected in recognition of their distinguished and continuing achievements in original research; election to the Academy is considered one of the highest honors that can be accorded a scientist or engineer."
So when this prestigious institution took the (nearly unprecedented) step of declaring human-caused climate change 'settled fact' in 2010, it was a forceful statement which should have put our continuing debate to rest. In reality, it has done no such thing.
In my writings on NewsVine, I am often astounded by just how few people are even aware of the Academy's writings on this topic. Typical comments on my seeds and articles include statements like "How can anything in science be considered "settled fact"?", or "There is no consensus on climate change.".
In reality, science can be 'settled fact', and the consensus is very strong. So with that, I'd like to take this opportunity to post the Academy's explanation on exactly why they describe human-caused climate change 'settled fact', and exactly what that means (and doesn't mean).
The selected passage from The National Academy Press, "Advancing the Science of Climate Change(2010)", is from pages 21 - 22. To provide for easier reading, I am not using NewsVine protocol by placing this lengthy passage in block quote. The passage is fully attributed by the link above. The National Academy of Sciences writes:
"From a philosophical perspective, science never proves anything—in the manner that mathematics or other formal logical systems prove things—because science is fundamentally based on observations.
Any scientific theory is thus, in principle, subject to being refined or overturned by new observations.
In practical terms, however, scientific uncertainties are not all the same. Some scientific conclusions or theories have been so thoroughly examined and tested, and supported by so many independent observations and results, that their likelihood of subsequently being found to be wrong is vanishingly small.
Such conclusions and theories are then regarded as settled facts. This is the case for the conclusions that the Earth system is warming and that much of this warming is very likely due to human activities.
In other cases, particularly for matters that are at the leading edge of active research, uncertainties may be substantial and important. In these cases, care must be taken not to draw stronger conclusions than warranted by the available evidence.
The characterization of uncertainty is thus an important part of the scientific enterprise. In some areas of inquiry, uncertainties can be quantified through a long sequence of repeated observations, trials, or model runs.
For other areas, including many aspects of climate change research, precise quantification of uncertainty is not always possible due to the complexity or uniqueness of the system being studied. In these cases, researchers adopt various approaches to subjectively but rigorously assess their degree of confidence in particular results or theories, given available observations, analyses, and model results.
These approaches include estimated uncertainty ranges (or error bars) for measured quantities and the estimated likelihood of a particular result having arisen by chance rather than as a result of the theory or phenomenon being tested.
These scientific characterizations of uncertainty can be misunderstood, however, because for many people “uncertainty” means that little or nothing is known, whereas in scientific parlance uncertainty is a way of describing how precisely or how confidently something is known.
To reduce such misunderstandings, scientists have developed explicit techniques for conveying the precision in a particular result or the confidence in a particular theory or conclusion to policy makers."