Peter Gallagher

Bat­tles between ortho­doxy and non-conformity are never won or lost. Only a naïve empiri­cist, or a reli­gion­ist who con­fi­dently expects all to be made clear at the final trump—when the prizes are handed out, truth is con­soled and error con­sumed by shame—could sup­pose otherwise.

There will be no “killer blow” to either the alarmist or scep­ti­cal side of dis­putes over the future of the cli­mate. Nei­ther bet­ter knowl­edge of under­ly­ing mech­a­nisms, nor longer nor more sub­tle mea­sure­ment will dis­cover an Answer. Empiri­cism under­de­ter­mines the truth (I see that Sin­clair David­son agrees).

But if wran­gling over the sci­ence of future cli­mate is headed for an inde­ter­mi­nate stand-off, can we nonethe­less expect gov­ern­ments to make ratio­nal, pro­por­tion­ate pub­lic poli­cies? How?

Ulti­mately, we are “short-changed” by the acts of per­cep­tion, as well as by our epis­te­mol­ogy, such that some model of the world must stand between us and shared expe­ri­ence; form­ing and fil­ter­ing the world. So each of us is, at best, a model-dependant real­ist. Two and a half mil­len­nia since Aris­to­tle leg­is­lated the prob­lem (“Ineluctable modal­ity of the vis­i­ble”, in Stephen Deadalus’ gloss, “… thought through my eyes”) it’s finally a com­mom­place that our mod­els are incon­sis­tent and incom­plete and break down when pushed. Even the most refined cos­molo­gies now depend on five-fold mashups (M-theory), or mul­ti­ple incon­sis­tent (quan­tum the­ory, gen­eral rel­a­tiv­ity) and, unavoid­ably, incom­plete but suc­cess­ful (New­ton­ian) descriptions.

This is not evi­dence that sci­ence is “socially con­structed”, much less that its propo­si­tions should be scru­ti­nised through an obscure semi­otic lens. It’s the every­day expe­ri­ence of con­flict between care­ful argu­ments based on “hard facts” that —as Ein­stein, as much as Sam. John­son, held—are unar­guably persistent.

What chance that obser­va­tion will rec­on­cile the evan­gel­i­cal dread of the alarmists and the show-me scorn of the scep­tics? None. What can we expect, then, from pub­lic pol­icy? Con­fu­sion? “Pre­cau­tion”? A naïve insistence—in the face of daily wit­ness to the contrary—that sci­ence will ensure every gor­dian knot has one, and only one, solu­tion (Alexander’s solu­tion was tren­chant, but obtuse, uninformative)?

Taken so far, this argu­ment might seem to lead to despair; if we can’t know any­thing for sure what’s the point of debate about ratio­nal pol­icy options? But the above is merely an espe­cially hard-edged state­ment of the epis­temic prob­lem of all pub­lic pol­icy (pri­vate deci­sions are a dif­fer­ent mat­ter; le coeur a ses rasions). Any thought­ful pub­lic pol­icy decision-maker reg­u­larly faces unre­solved con­flicts, insuf­fi­cient data and good argu­ments for con­trary courses espe­cially in the face of uncer­tainty. This is the nor­mal case. Ross Gar­naut is exag­ger­at­ing if he means that cli­mate change is the only “dia­bol­i­cal problem”.

There is, in fact, plenty of need for informed debate despite the prob­a­bil­ity of un-resolved con­flict. Although we will never have a “con­sen­sus view” (it’s non­sense to speak of phys­i­cal sci­ence in this way) we cer­tainly need not despair of hav­ing bet­ter knowl­edge in the future or of hav­ing more or lower-cost options and pos­si­bly (his­tory shows us) dif­fer­ent priorities.

The rules for the best pub­lic policy-making in the face of uncer­tainty and poten­tially costly choices are well-known and apply equally to emissions-control as they do to pub­lic health or indus­try assis­tance. They do not include rush­ing into high-cost, poten­tially futile, single-option “solu­tions” intended to sig­nal bona fides to the United Nations.