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More on the Regulation (or Not) of Expression and Emissions

Here’s the second of my two-part series at AIER comparing the classical-liberal case for freedom of expression with the widely accepted case for government regulation of physical emissions (i.e., of physical pollutants). Two slices:

In my previous column, I argued that liberals’ confidence in freedom of expression is perhaps inconsistent with ready acceptance of the case for using the government to ‘control’ air pollution and other negative externalities. Ideas are emitted and spread from human minds and mouths just as greenhouse gasses are emitted and spread from automobiles and factories. And like greenhouse gasses, ideas can be harmful. Yet government officials whom liberals distrust to police the emission of ideas are trusted by those same liberals to police the emission of physical elements, such as greenhouse gasses.

There might be a sound explanation for this apparent inconsistency and, hence, good reasons to accept government intervention to control physical pollution. But if so, these reasons aren’t immediately obvious.

Our wise awareness that we can never be sure just which ideas are right and which are wrong should apply to physical emissions. Take what is today the big bad monstrous emission: CO2. Very many people believe as a matter of indisputable fact that in an ideal world the amount of CO2 emissions would be zero. Perhaps this belief is true, but perhaps not. Consider this recent observation from the science writer Matt Ridley: “Given that roughly ten times as many people die of cold as die of heat globally, and that this is true even of countries like India and Italy, warming has meant fewer people dying.” Because CO2 emissions do likely raise the earth’s average temperature, perhaps these emissions produce, on net, positive benefits.

I write “perhaps” because I don’t know. But because human life is valuable, the above claim isn’t ludicrous. Indeed, I believe it to be plausible. The larger point, however, is that no one knows.

While science can tell us much about relatively simple relationships – for example, the extent to which CO2 emissions do in fact warm the earth, the various available technological means for reducing the amount of CO2 in the atmosphere, and whether more people really do die from cold rather than from heat – we can never be certain that such pieces of scientific information are correct. A more foundational problem, however, is that science becomes ever more error-prone the greater is the number of detailed variables across space and time that it is asked to account for and predict. Science cannot tell us today how human ingenuity will tomorrow respond to climate change – how an agronomist might innovatively change farming practices to turn rising temperatures from a danger into a boon, how a civil engineer might redesign dikes to protect coastal communities from rising sea levels, or how individuals will change their locational preferences to reduce their exposure to climate change.


The above ruminations, standing alone, clearly don’t amount to a credible case against emissions taxes and other government interventions meant to control pollution. But by contrasting the accepted – and, I believe, successful – laissez-faire approach to dealing with peaceful expression with the highly interventionist approach to dealing with industrial and commercial activities that emit physical substances into the atmosphere, relevant questions are raised that prod us to think more carefully about widely accepted justifications for government interventions.

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