Twitter recently decided I needed to see an exchange between some angry greens and snide conservatives that went something like this. Snide conservative: Greens have been telling us for decades to panic about overpopulation, acid rain, pollution, the ozone layer and now climate change. Yawn. Angry greens: Yeah, but that’s because we took action and fixed all those issues, but now we’re ignoring the climate crisis because the good conservatives who used to care are all gone and now all we have are bad conservatives who hate the planet (and are stupid).

Twitter is a factory of sloganeering, insults and cheap shots, but unfortunately it also seems to be the place where a lot of journalists form their views on things, so it’s worthwhile to talk this spat through. For context, while the above exchange was happening the news from Reuters was “Global 2021 coal-fired electricity generation surges to record high.”

Is that because stupid planet-hating conservatives are in charge everywhere? Hardly.

The laws of economics are in charge everywhere, which is why political leaders of all stripes (including greens) are now ordering their coal-fired power plants to reopen and go full blast. They are desperate for the energy and the alternatives are far costlier.

Regarding the Twitter thread, there are two questions to ask. First, do environmental advocates have a history of exaggeration, and second, why aren’t we stopping climate change even though we tackled all those other issues? My answer to the first is yes: they’re engaged in political advocacy and they use fearmongering to get attention. The failed apocalyptic predictions of people such as Paul Ehrlich and Al Gore have been documented elsewhere. I have written many times on how this plays out in the climate change issue with respect to claims of things such as floods and storms, extreme weather, wildfires, economic growth, etc. The green movement got a lot of political traction over the years by announcing the end of the world, but people are tuning it out now, for valid reasons.

On the second issue, we aren’t approaching climate change the way we did for, say, acid rain because the costs and benefits of action are completely different. Simply put, for some of the earlier environmental issues there were emission-control options that yielded dramatic improvements at low cost. In the case of carbon dioxide, the control options cost a lot and accomplish little. Hence the difference.

Canada, like most industrialized countries, used to have a problem of high carbon monoxide (CO, not CO2) levels in our cities. In the mid-1970s, 84 per cent of Canadian urban air quality readings violated health standards for carbon monoxide. But technology was developed (mainly catalytic converters for automobile tailpipes) that drastically reduced the emissions at a low cost. Problem solved. As my colleague Elmira Aliakbari and I showed in a 2017 report published by the Fraser Institute, data from Environment and Climate Change Canada (ECCC) show ambient carbon monoxide levels fell by 90 per cent from 1975 to 2015, and since 2011 no monitoring sites anywhere in the country have shown carbon monoxide violations. This happened despite the economy growing 240 per cent in size and a tripling of the size of the vehicle fleet.

A similar story exists for sulphur dioxide, which is connected to acid rain, and fine particulate matter which contributes to smog. Technology in the form of smokestack scrubbers and (in the case of sulphur, processing methods that remove sulphur at the refinery stage) dramatically reduced both emission types. The removal of lead from gasoline also eliminated lead from the air.

Depletion of stratospheric ozone was tied to the use of chlorofluorocarbons (CFCs). By the time the problem was discovered there were relatively inexpensive substitutes available so CFCs were banned in 1987 under the Montreal Protocol.

Then around 1988 the conversation turned to carbon dioxide and global warming. Despite some early hope that a global treaty like the Montreal Protocol could work the same magic, it quickly became apparent that the economics were very different. Carbon dioxide is closely tied to fossil fuel use but there are no scrubbers and no catalytic converters that can capture it before release. Large-scale global emission reductions would require large-scale global cuts in fossil energy use for which no feasible alternatives exist. And even aggressive emission reductions would barely affect the global CO2 concentration for a century due to the size of the natural carbon cycle. Meanwhile, the socioeconomic costs of warming, notwithstanding green fearmongering, have turned out to be small, especially in comparison to the benefits of energy-driven economic growth. Climate models have overpredicted atmospheric warming for decades, while the IPCC (and many climate scientists) have been busted for using deliberately exaggerated emission forecast scenarios.

That’s why we haven’t yet, and likely never will, respond to the climate issue the way we did to acid rain, urban smog and other previous environmental problems. The costs and benefits of feasible policy options differ. It’s not political, it’s the economics.