This morning I awoke to the joyous tones of BBC Environment Correspondent Roger Harrabin on BBC Radio 4, expounding the new consensus on climate change. At last (he told us) the alarmists and the sceptics are edging to the middle ground, very nearly singing off the same hymn-sheet. The Climate Wars are almost over.
We all agree that CO2 is a greenhouse gas. We all agree that human activity is affecting the climate. We are converging on a figure for climate sensitivity of around 1.7oC (Climate Sensitivity is the theoretical warming associated with a doubling of the atmospheric CO2 level, on an “other things being equal” basis. Note that a fixed warming per doubling amounts to a law of diminishing returns).
So the good news is that warming will be slower than the IPCC’s worst alarmist forecasts, which tended to use a sensitivity figure of around 3.5o. We have more time to prepare. But the bad news is that climate change is real, is man-made, and will sooner or later do huge damage unless we radically change our ways, and (as I would argue) do vast damage to our economies.
Thank heaven that we have the BBC fulfilling its mandate and presenting us with such wise and balanced advice! Thanks heaven that the arguments are over, and we all know where we stand!
But before you break open the champagne to celebrate the outbreak of peace and the cessation of hostilities, there are several elephants in the room. Several massive but critical implicit assumptions that Mr. Harrabin has failed to resolve, or even to raise.
Is mankind responsible for the recorded increase in atmospheric CO2 levels? Certainly there is a (fairly) good correlation between the rise in CO2 since say 1950, and the global temperature trend (though the CO2 trend is much more linear, while temperature has ups and down, and in fact declined from 1950 to 1975). But temperature has been on a broadly upward trend since the early 19th Century, long before the increase in CO2. That upward trend is exactly comparable to the increase before the Mediæval Warm Period 1000 years ago, before the Roman Optimum 2000 years ago, and indeed before cyclical up-turns on a roughly 1000 year timescale throughout the current Interglacial. This seems much more like astronomical cycles that a CO2-driven effect.
In any case, anthropogenic CO2 emissions are estimated to be only around 3% of the total CO2 cycle, which is largely driven by natural phenomena — volcanoes (both on land and under-sea) and biological processes. A few weeks of Icelandic volcanic eruptions can negate years of desperate attempts to reduce man-made emissions.
And the evidence over hundreds of thousands of years is that the CO2 cycle follows the temperature cycle after 800-1000 years, and therefore cannot be the cause of it. The mechanism is clear: as oceans warm, they are able to contain less dissolved CO2, which ends up in the atmosphere. (There is fifty times as much CO2 in the oceans as in the atmosphere). It is much more likely that the recent increase in atmospheric CO2 is primarily driven by rising temperatures, not human activity. So action we take to reduce emissions will have no effect at all (apart from bankrupting us).
Is CO2 the only factor driving the terrestrial climate? Indeed, is it a significant factor at all? It beggars belief that a colourless, odourless, non-toxic trace gas in the atmosphere, currently at only 0.04%, can be the primary driver of terrestrial temperature — especially since on a geo-historical perspective, the CO2 level has been much higher in the past, perhaps twenty times higher. And those periods were not associated with Warming — indeed they partly coincided with an Ice Age.
CO2 is just one minor factor amongst many in a vast and chaotic climate system which is poorly understood and very difficult to model. CO2 is not even the most serious greenhouse gas. Both water vapour and methane have a bigger effect — and we can do nothing about water vapour until we can stop the winds blowing over the ocean.
In any case, there’s that big hot ball in the sky which largely drives the earth’s energy economy. The Sun. And over the last 1000 years, there’s a very good correlation between solar activity and sunspots, on the one hand, and global temperatures on the other. But a rather poor correlation between CO2 and temperature.
The IPCC dismisses the effect of the Sun, because its luminosity is remarkably constant. However its magnetic field is not. Linked to sunspot cycles, it is very variable, and there is increasing evidence of a causal link between sunspots, the Sun’s magnetic field, the incidence of cosmic rays on the earth, terrestrial cloud formation, and albedo (the earth’s reflectivity, largely driven by cloud cover). The difference is this: that there are hard data to confirm the link between solar activity and temperature, whereas predictions based on the IPCC’s CO2 theory have failed again and again.
Will the activity we are taking to mitigate climate change actually have any effect? If man-made CO2 is not a significant driver of climate, then No. But even if it is, I have argued elsewhere that (A) Intermittent renewables do not achieve major reductions in emissions; (B) But they do drive up energy prices, causing energy intensive businesses to move to jurisdictions with lower energy prices and laxer emissions rules — arguably increasing emissions; (C) with 1200 new coal-fired power stations in the global pipeline, covering the UK with wind turbines is simply whistling in the wind (literally and figuratively).
So I’m sorry, Roger, but the battle isn’t over (and the alarmists are losing it!). But right now, until the final collapse of the orthodoxy, we are investing massive, front-loaded sums of money in mitigation measures which can never achieve their aims — even if the IPCC were right. And its not. We are mortgaging our children and bankrupting our grandchildren with bizarre policies based on highly suspect science, with technologies that cannot deliver even in their own terms.
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