The argument that a CO2 alarmer can always fall back upon when pushed about this, that, or the other flaw in dire prognostications about our impact on the climate system is that there might, there just might possibly might, be a risk that rising CO2 will be dangerous. This is a big climb down from the heady days of hockey sticks and ’10 months to save the world’ and so on, when some assured us that the science was settled, that temperature rise would be inexorable, and that crippling our economy, our way of life, and the material aspirations of most of the world’s people, was mandatory, and should have been done yesterday. That led to legislation like the UK’s notorious Climate Change Act, and to children being scared deliberately in classrooms by teachers, on the TV by the government, and anywhere else that zealous campaigners might reach them. It has led to massive, market-distorting subsidies for unreliable, expensive, and environmentally damaging technologies such as wind and solar farms for mass energy production. And who can put a price on the depression of spirit that the widespread propaganda of doom must have produced?
But is this fallback adequate to support the massive interventions already done, and those that some would wish for the future? I think not. Not nearly good enough.
The data on the ground is consistent with the rising CO2 having a such a modest impact on the climate that it has proven impossible to reliably extract it. Lamb long argued that we needed a far better grasp of the history of climate variation and its causes t before we might hope to identify human impacts with confidence on a global scale (we know we can have an impact on local scales – growing a hedge, for example, can reduce average windspeed in your garden, building a city can increase average temperature, removing a forest, building a dam, planting a field, … and so on, and on). Here are some recent papers supporting the notion that natural, i.e. pre-existing sources of variation can account for most of recent climate variation: http://notrickszone.com/2017/02/27/20-new-papers-affirm-modern-climate-is-in-phase-with-natural-variability/
Other faults with CO2 alarm-driven science have been highlighted in the extensive series of papers and reports from the NIPCC (Non-governmental International Panel on Climate Change): http://climatechangereconsidered.org/
Economic analyses favouring drastic intervention in society now, most notably the Stern report, have been exposed as relying on implausibly high discount rates – contrived presumably to provide the results required. Contrivances such as the ‘Social Cost of Carbon’ (SCC) have also suffered for concentrating on projected harmful effects of increased CO2 levels, and neglecting the far more clearly established benefits. For example, here is recent testimony from a statistician who points out the utter unsuitability of SCC claims being used as guidance for policymakers: http://www.climatedepot.com/2017/03/03/statistician-trashes-obama-cost-estimates-of-climate-manipulated-by-regulators-bureaucrats/
Even when the IPCC computations are taken at face value, and the economics of mitigation versus adaptation are considered, the case for radical intervention now is undermined. The former finance minister (Chancellor of the Exchequer) of the UK, Nigel Lawson, in a temperate and carefully argued book makes this clear: https://www.amazon.co.uk/Appeal-Reason-Cool-Global-Warming/dp/0715638416
So what are we left with? It would be grand if a reset button could be pressed to take us back say 50 years, and the genie of CO2 scaremongering be left inside the walls of the academy, never to be let out as a serious matter for policy makers unless a far stronger, evidence-based case could be made for it. Calm and erudite professors would readily appear on TV to ridicule any attempts by agitators to scare us into precipitate policv making. These are notions for academics to juggle with, like to what extent should we move all our cities deep underground to protect ourselves from a massive strike of meteors? How many angels can dance at the same time on the head of pin? What would happen if all water on the planet went saline? Or if the speed of light suddenly changed to 20mph? And so on. Lots of interest. Little use for policy.
But we are where we are, and the Genie of CO2 Fearfulness is out and about, wreaking harm all over the place. It will never disappear, but it can surely become less respectable. And , can we please have the ‘this might just possibly be dangerous’ discussions confined to bars and seminar rooms where much enjoyment can be had all round? But not in the public square accompanied by trumpeters, wailers, gnashers of teeth, doomsayers, snake-oil salesmen, and sundry shallow opportunists. We’ve had all that, and it has been wretched. We all have better things to worry about.