Are We Experiencing a Climate Change Emergency?

Guest post by Ian Aitken

Some scientists (epitomized by Dr. Michael Mann) and environmentalists (epitomized by Sir David Attenborough) and climate change campaign groups (epitomized by Extinction Rebellion) hold the opinion that we are experiencing a global ‘climate change emergency’ (the term that seems to be supplanting the pleasingly alliterative ‘climate change crisis’), to the extent that lately cities/counties declaring a ‘climate change emergency’ has become the vogue. Indeed the British Parliament has just declared a national climate change emergency, the first country in the world to do so. However some scientists disagree, primarily arguing that whilst it is true that even modest warming creates some harm (such as coral bleaching) the 10C of post-industrial warming that has occurred has in all probability been net-beneficial for humans and the environment as a whole. So where does the truth lie? Are we really experiencing a climate change emergency?

In my Climate Change Misconceived earlier essay, that explored the dissonance in public understanding of the climate change issue, I contended that based on the best available science and empirical evidence post-industrial climate change (whether it be man-made or natural) apparently has not caused exceptional or accelerating rises in sea levels, has not caused an increase in the frequency or intensity of extreme weather events and has not caused accelerating global species extinctions. Similarly, whilst heat-related deaths have increased with the warming, cold-related deaths have fallen even more – so net-mortality has improved. Furthermore according to Dr. Indur Goklanky, science analyst for the US Department of the Interior, ‘Carbon dioxide fertilises plants, and emissions from fossil fuels have already had a hugely beneficial effect on crops, increasing yields by at least 10-15%.’ So it has apparently been net-beneficial for agriculture. Professor Richard Tol of Sussex University (after reviewing 14 different studies of the effects of future climate trends) concluded that global warming would likely be economically net-beneficial for the world up to 30C. So with only 10C of warming it certainly appears to have been economically net-beneficial to date. Against all this we have to set the effects of ocean warming and reduced alkalinity that have probably been net-harmful for marine life. Taken as a whole, the positive changes from post-industrial climate change appear to have outweighed the negative changes – and the negative changes (in particular rising sea levels) are apparently currently happening sufficiently slowly for us to adapt to them.

Now I’m profoundly conscious of the fact that the above ‘weighing of the scales’ is trite – and I’ve deliberately omitted referencing the dozens of studies that I could have supplied to support my contentions (because that would not be appropriate in a short essay). Nevertheless I think most scientists would agree that climate change results in both harms and benefits and with modest warming the latter may prevail. Perhaps if you only consider the harms, believe them to be potentially dangerous and to require urgent attention, then you can convince yourself that we are experiencing a climate change ‘emergency’. The syllogism of the climate change alarmists appears to be: climate change has potential dangers; climate change is happening now; therefore the climate change potential dangers require urgent (decarbonization) action. This isn’t the most convincing of logic because (quite apart from ignoring the benefits of climate change) the conclusion requires that we ignore the probabilities of the potential dangers coming to fruition. Furthermore even if the potential dangers did come to fruition it may not be socially, environmentally or economically sensible to take urgent (decarbonization) action to mitigate those dangers.

There is no doubt that the Industrial Revolution has had some seriously adverse effects on humanity and the environment, primarily through ocean, land and atmospheric pollution, deforestation, land degradation, urbanization and intensive farming (coupled with over-hunting and over-fishing); the point is that climate change, whilst a very convenient ‘universal scapegoat’, has not (certainly to date) been the prime culprit for all the negative ramifications of industrialization. Consequently looking at the evidence as a whole it is hard to see how climate change that so far has probably been net-beneficial for humans and the environment, that has lifted us out of the misery of the Little Ice Age that preceded it, with its droughts, crop failures, famines and epidemics, and has (not coincidentally) been accompanied by soaring wealth and life expectancy (according to the World Bank – World Development Indicators 2014) could reasonably, in the round, be described as an ‘emergency’; indeed quite the opposite. Conversely we know that fighting climate change has had seriously adverse consequences to date. As Matt Ridley puts it, ‘Building wind turbines, growing biofuels and substituting wood for coal in power stations — all policies designed explicitly to fight climate change — have had negligible effects on carbon dioxide emissions. But they have driven people into fuel poverty, made industries uncompetitive, driven up food prices, accelerated the destruction of forests, killed rare birds of prey, and divided communities… globally nearly 200,000 people are dying every year, because we are turning 5 per cent of the world’s grain crop into motor fuel instead of food: that pushes people into malnutrition and death’. So so far we have been effecting climate policies that have probably been net-harmful to humans and the environment in order to mitigate climate change effects that have probably been net-beneficial for humans and the environment (just in case they become net-harmful many decades in the future).

We know that climate change is happening – but the fact that climate change is happening (as it has for billions of years) does not in itself constitute an ‘emergency’ (or even necessarily a serious problem); global warming and climate change are not intrinsically bad things – few would want to return to the pre-industrial climates of the Little Ice Age. As the IPCC stated in their last Assessment Report, ‘Climate change may be beneficial for moderate climate change’. We are experiencing moderate climate change and it has indeed apparently been net-beneficial. In as much as a ‘climate change emergency’ could be said to exist today it is only in the virtual world of the most extreme projections of the climate change computer models – and you and I do not live in the virtual world (unless you believe that we are all living in The Matrix, in which case our climate models are climate simulations of simulated climates within a world simulation). It’s perfectly reasonable to speculate about the possibility of a climate change emergency many decades in the future – but there certainly does not appear to be one now.

So what of the future? Can we at least say that there will be a climate change emergency in the future even if there has not been one so far? A basic difficulty here is establishing how much warming constitutes an ‘emergency’. There is no ‘Goldilocks’ average surface temperature that is ‘just right’ for the Earth and beyond which we face an ‘emergency’. As Dr Gavin Schmidt, Director of the Goddard Space Institute, has said, ‘No particular absolute global temperature provides a risk to society’. In fact it is impossible to specify a threshold for global warming beyond which the climatic effects become net-harmful let alone a ‘catastrophe’ so imminent that it constitutes an ‘emergency’. As the IPCC put it in their latest Assessment Report: ‘Climate impacts [from global warming]… are geographically diverse and sector specific, and no objective threshold defines when dangerous interference is reached. Some changes may be delayed or irreversible, and some impacts could be beneficial. It is thus not possible to define a single critical objective threshold without value judgements and without assumptions on how to aggregate current and future costs and benefits.’ In plain English defining when global warming becomes an ‘emergency’ is at best a matter of opinion and at worst meaningless. Perhaps to an ardent environmentalist the potential loss of a single species of Amazonian tree frog due to global warming would be a global climate change ‘emergency’ – but I don’t think most of us would agree.

So what about the maximum 20C warming (above pre-industrial levels) target in the Paris Climate Accord? If we exceed that then would that be an ‘emergency’? Professor Roger Pielke Jr. explained in 2017 that this target ‘is an arbitrary round number that was politically convenient. So it became a sort of scientific truth. However, it has little scientific basis but is a hard political reality.’ As Mark Maslin puts it in Climate Change – A Very Short Introduction, ‘It should always be remembered that this is a political number, as the definition of what is dangerous climate change is a societal rather than a scientific decision.’ Despite this, the New Scientist (in October 2015) declared that such warming would be ‘catastrophic’, which, given that we have already experienced 10C of warming, means that we only have another 10C to go before we hit ‘catastrophe’. In fact because the global average surface temperature varies dramatically throughout each year (about 3.80C) every year (around July) we already experience global average surface temperatures far in excess of the 20C goal – without apparent catastrophic (or, indeed, noticeable) effect. And (because warming varies by geographical region) Europe has actually already experienced about 20C of warming over the last 150 years, without any ‘climate change catastrophe’ happening. As Michael Hart puts it, in Hubris: The Troubling Science, Economics and Politics of Climate Change, ‘The warming of the atmosphere by a degree or two over the course of a century presents no significant direct harm and in many ways may be beneficial… historically periods of warming have been beneficial to humans, flora and fauna alike. If the GHG hypothesis [the IPCC’s theory] is correct, its principal effect will be at higher latitudes at night and in winter, i.e. in reducing heat loss to the upper atmosphere and out into space. Warmer winters and warmer nights will generally extend growing seasons and increase harvests.’ So the idea that just one further degree of global warming would be a ‘catastrophe’ or an ‘emergency’ appears to be profoundly misconceived. Yet we are now being told that just half a degree of further warming would be catastrophic, an assertion that appears ridiculous (taking any reasonable interpretation of the word ‘catastrophic’). Based on paleoclimatology estimates 50 million years ago the Earth was about 80C warmer than it is now (and 500 million years ago up to 140C warmer) and no ‘tipping point’ into ‘climate catastrophe’ occurred. Perhaps when alarmists describe even half a degree of warming as ‘catastrophic’ they are doing so primarily for rhetorical purposes in order to create an impression of urgency and alarm in policymakers and help justify the almost inevitable global recession/depression that would result from the societal-transformational policies designed to limit warming to half a degree.

Take, for instance, Extinction Rebellion’s interestingly-named The Truth tab on their web site. This is devoted to the most extreme, highly improbable, projections of climate models, none of which are associated with a mere half a degree of warming. Yet here they imply that even half a degree of global warming would be ‘utterly catastrophic’, that ‘a mass extinction event… is underway’ and that we only have until 2030 to avoid such a catastrophe. In support of these claims they provide a link to the IPCC’s SR15 report; yet this report says little more than that climate risks will be higher if we experience one degree of further global warming than if we experience a half a degree of further global warming – which is not particularly contentious and obviously not remotely equivalent to any hyperbolic claim of ‘catastrophe’ or ‘mass extinction’, neither of which terms appear anywhere in the report. In fact the closest the report comes to these terms is where it states, ‘species loss and extinction are projected to be lower at 1.50C of global warming compared to 20C’. Furthermore the fact that a change has downsides does not necessarily mean that it will be net-harmful and does not necessarily mean that it makes economic sense to take action to avoid that change. Based on the climate economics Nordhaus DICE Model if we adopted a global climate policy of limiting warming to the half a degree target humanity would be $14 trillion poorer compared to doing nothing at all about climate change. To try to get $14 trillion into some kind of perspective it is about 500 times more than was spent on all the Apollo missions to the moon between 1960 and 1972 (at the time the most expensive scientific project of all time). This can reasonably be described as ‘serious money’ that might better be spent on relieving known and pressing global problems, such as poverty, hunger and disease than on decarbonization. So even if we accept that the risks of climate change are higher at a degree of warming compared with a half a degree of warming that does not necessarily mean that it would be wise (or even cost-effective) to try to avoid such warming through urgent global decarbonization. Saying (in effect) that we must urgently, radically decarbonize the world in order to reduce adverse climate impacts, however small and however easily we might adapt to them (and whatever the human and environmental costs and impacts of decarbonization) is obviously highly questionable (to put it charitably).

A key question here is how we define a ‘climate change emergency’. Clearly if ‘runaway global warming’ were about to occur then that would constitute an ‘emergency’. This is global warming sufficient to induce out-of-control amplifying feedbacks (i.e. passing a tipping point into irreversible global warming, such as is thought by some to have happened on Venus). But even the IPCC admit that ‘a runaway greenhouse effect—analogous to [that of] Venus—appears to have virtually no chance of being induced by man-made activities.’ For anything that could reasonably be called a ‘climate change emergency’ to even potentially occur (for example, the collapse of the West Antarctic Ice Sheet or the failure of the Gulf Stream or vast methane release from melting permafrost) would require the worst possible case scenarios of carbon dioxide emissions (that would be virtually impossible to occur) and worst possible case values for climate sensitivity (several times their most likely value based on the best available empirical studies to date). Even the IPCC describe such climate disruptions as ‘very unlikely’ or ‘exceptionally unlikely’. So a ‘climate change emergency’ many decades from now is not absolutely impossible – but it appears extremely improbable. Probably the greatest real risk from climate change in the foreseeable future is sea level rise and the IPCC say that sea levels could rise 10 centimeters more with one degree of further global warming compared with half a degree. But even if it happened would that really constitute a global ‘climate change emergency’? If you live on the south Florida coast and the sea was previously lapping your garden but now is lapping your front door then it might well be an ‘emergency’ for you – but not surely a global ‘emergency’. Even if we were to call this a global emergency there is very little we can do about it (other than adapt).

Climate change has been happening for the 4.5 billion years of the Earth’s life and will continue to change into the future (at least for the next 5 billion years, at which time we will experience some extreme global warming as the dying sun turns into a Red Giant and vaporises the Earth); there is nothing to be done about that (unless you want to face the huge risks of geoengineering the climate). Furthermore it is generally believed that there is about 0.60C of global warming ‘in the pipeline’ from past carbon dioxide emissions. So unless currently non-viable and unproved technologies (like Carbon Capture and Sequestration) remove these emissions a half a degree of future warming is inevitable (even if we stopped all global carbon dioxide emissions overnight). So thanks to this half degree of warming is the sixth mass extinction event now inevitable, as Extinction Rebellion claim? It would appear that the alarmists are claiming that almost any change in the Earth’s climate, even a relatively trivial half a degree of warming, constitutes an existential emergency. Here we are getting into the realms of the ridiculous, if not surreal. If by a ‘climate change emergency’ we actually mean serious climate disruption then claims that we are experiencing a climate change emergency today appear tenuous in the extreme (if not absurd). Claims that there could, possibly be a climate change emergency in the future are perfectly reasonable – but the idea that such an emergency will occur if we don’t urgently, radically globally decarbonize appear tenuous in the extreme (if not absurd).

via Watts Up With That?

http://bit.ly/2EzRDqa

May 25, 2019 at 04:26AM

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