My friend Ian is a bright and amusing fellow, albeit that he has sometimes been a bit of a sucker for climate change alarmism. The other day, he posted a prediction by Penny Sackett that we had just 5 years to save the world from disastrous global warming. Now, Penny Sackett is not quite as well established as Tim Flannery as an object of mirth, but she has recently been the object of considerable derision, since it is now 5 years since that prediction, and of course, there has been no global warming at all during that 5 years, let alone disastrous global warming. So I thought Ian might well be having a bit of a laugh posting her 5 year old prediction as if it were recent.
But it seems not. He has asked me if really dispute the existence of global warming.
There are things that are settled and things that are not. It is settled that the world has warmed and cooled numerous times in the past, and that these changes cannot possibly have been caused by man-made CO2 emissions, because these changes occurred long before mankind was around in any numbers to make any difference. It certainly warmed during the last third of the 20th century. Equally certain is that temperatures have not continued to increase this century – all but the activists agree that there has been no material global warming for the last 15 years or so (see for example the Met Office report The recent pause in global warming: What are the potential causes?). Neither has it cooled during this period. So it has remained relatively hot, by recent standards.
Also well-settled, beyond any doubt it seems to me, is that the models used by the IPCC and others, predicated both on the greenhouse gas effect and a positive feedback effect, are fundamentally wrong. CO2 levels have continued to rise (they are now north of 400 ppm), and yet global temperatures have not. Over the last 15 years or so, global temperatures have in fact been well outside the uncertainty range of the predictions made by the IPCC models. The scientific method involves developing hypotheses, and testing them against actual data. The hypothesis that global temperatures are rising out of control has been tested by actual data over the past 15 years, and has been clearly shown to be wrong. As have numerous other predictions from the 1980s and 1990s about how the expected rise in temperatures would affect our planet. The Artic has not melted. The Antarctic has been getting icier. The Gulf Stream has not reversed. Australia has not been ravaged by drought. Polar bear populations have been getting bigger, not smaller. And so on. So, as a matter of science, the hypotheses that failed to predict the actual data should be rejected.
This is not to say that C02 is not a greenhouse gas. It plainly is. But the science is not settled as to its effect. In particular:
- Compared with H2O, the quantities of C02 in the atmosphere are tiny. Sometimes, tiny amounts of something can have a big effect. It is not settled how much greenhouse gas effect C02 has in our atmosphere.
- Some effects has positive feedback, so as to give rise to the possibility of a “tipping” point, some have no feedback effect, and some have a negative feedback. Which is this?
- Historically, there have been times in the planet’s past when there has been much more C02 in the atmosphere than now, and when it was much hotter. It is not settled whether high levels of C02are the cause or the effect of higher temperatures.
Certainly, there is a starling anomaly for the alarmists to address: the amount of C02 in the atmosphere has been rising, but temperatures have stubbornly refused to move with them since the exceptionally hot El Nino year of 1998.
The debate has been hampered by vested interest. The alarmists suspect big business of loading the dice against action on climate change. That is doubtful: the leading voices in the sceptical camp – Anthony Watts of WUWT, Jo Nova, Andrew Mountford of Bishop Hill, Matt Ridley and so forth – appear to survive on the relatively meagre resources provided by their tip jars and adverts on their websites. On the other side, the biggest business of all – government – uses huge amounts of public money to support the alarmists. As a lawyer, I ask the question, “cui bono?” – a question which was already well established by the time of Cicero. Who benefits from any particular assertion? Time after time, I have seen expert evidence in court proceedings, which is supposed to be neutral and independent, loaded in favour of whichever party would benefit from that evidence. In this case, the answer is, I fear, all too obvious. Those who benefit from climate alarmism are climate scientists whose grant money has sky-rocketed since they started on this tack, and governments, for whom alarmism always brings the opportunity for more tax. That bias has been exacerbated by Climategate – the emails disclosed by that event show that there is a coterie of climate scientists around the world who are determined to stifle any scientific opinion that runs counter to their orthodoxy. And furthermore, that the climate scientists in that coterie cooperate together to seek to hide unwelcome data, such as for example data showing that the world has previously been hotter than this (it seems pretty clear that it was much hotter than the alarmists would like us to know both at the time of the Roman Empire and during the Medieval Warming Period). It is a statement of the blindingly obvious to anyone with any scientific training that each of these approaches should be an anathema to any scientist acting bona fide.
But evidence should not be rejected merely because it is self-serving. Just looked at more critically.
Neither is Occam’s Razor an infallible guide to the truth. But again, it is right to ask the question, “Which is the simpler and more natural explanation for so many people believing in the climate change story? That the climate models which have proved to be so evidently wrong over the past 15 years are somehow right after all? Or that the populace is as much drawn to apocalypse messages as it has always been?”. Sometimes, the unlikely, complex explanation is right. But again, scepticism is called for before accepting the unlikely.
So what did cause the warming in the later part of the 20th century? The reality is that nobody knows. The sun is a candidate, although variations in sun activity cannot easily explain what has happened. CO2 might have had a role to play, even though the models (and hence the predictions of “tipping point”) are plainly wrong and that explanation does not go anywhere to explain earlier similar warming periods.
Now the whacky bit. So convinced are the alarmists by the models predicting warming that they cannot quite believe that has not in fact warming for the last 15 years. So they ask “Where has the heat gone?” This question is of course predicated on the assumption that it must have been getting hotter, even though the thermometers tell a different story. So they have theorised that the expected heat has disappeared into the Pacific Ocean. Or the Atlantic Ocean. Or that is has been reflected away. These theories do not look promising: in particular there is simply no evidence to support them.
What will happen next to global temperatures? Again, the reality is that nobody knows. It seems more or less certain that we are due for another ice age, but that might be soon, or might not happen for ages. In the meantime, it might get hotter, and it might get colder. What can be said with certainty is that the predictions of the alarmists are wholly unreliable, because they have proved to be wrong about so much in the past.
Another uncertainty: what would be the effect of warming? It is more or less universally agreed that cold periods are a bad thing (populations have historically thrived during warmer weather and suffered decline during colder periods). But what about a few degrees warmer than now? Views vary. Personally, I incline to the view that the advantages would outweigh the disadvantages. In this view, I am somewhat accompanied by the many people with the luxury of choosing where to lead their lives who have moved to warmer climates such as Florida, Queensland and the South of France.
At the very least, people who have moved to warmer climates (I am one of them) seem to me to be generally rather happier and more cheerful that those who choose to stay freezing their arses off in the sleet. So, there might be this negative feedback effect: that if it does start warming up again, there might be a lot less whingeing about it.