Climate Change - Whatever happened to the Next Ice-Age ?

 Amidst all the discussion about the perils of global warming, there has been no mention recently of when we might expect the start of the next Ice-Age....

This was a topic that hit the headlines some years ago and was all the rage for a year or two before fading into obscurity. It is probably no coincidence that this media fade-out coincided with the increased coverage in the media about global warming and its wider implications for our future well-being.

There is now no doubt that our climate is warming – and doing so quite rapidly. There is also little doubt that our large-scale release of greenhouse gases since the dawn of the industrial era in the early 1800s will have contributed significantly to this process.

However, despite the views of some environmentalists, our planet and its atmosphere are chaotic and unpredictable beasts, and the jury is still out on whether ‘man-made’ climate warming is the principal, let alone the only, contributor. 

We need to look at past climate history to get a fuller picture before we jump to conclusions about how we should manage our long-term future (I’m assuming of course that we still have one - this may be somewhat presumptuous, now that the threat of nuclear war familiar to those of us old enough to remember the 'halcyon' days of the 1970s and 80s has resurfaced)…..

Climatology is a well-established field of study, and uses a wide range of tools to establish how our climate has developed over past epochs. We have established that our planet was largely covered with water-ice until relatively recently in geological terms (The most recent inter-glacial period started ca 30,000 years ago, reaching a peak ca 20,000 years ago and ending with the start of the Pleistocene epoch ca 12,000 years ago). 

Although there is, of course, a degree of variability in the timing, glacial- and inter-glacial periods are known to alternate in a complex climactic cycle, and some authorities still believe that the next glacial period could start at any time now. This was the prime concern of pundits during the last ‘phase of interest’ in the media, before all talk of climate cooling was eclipsed by the focus on the global warming debate.

Why is this a concern, and what would be the consequences of a new Ice Age for our modern society ?

In a word.….Disastrous.

Although there would be a lead-in period, and this could be quite protracted (of the order of 50-100 years), even during the early part of the transition large parts of the northern hemisphere would quickly become too cold for crops to grow. The bitter winters that ensued would be barely survivable for many northern hemisphere cities, given their relatively high latitudes. The UK would be particularly badly affected, dependent as we are on a particularly favourable combination of warm ocean currents and prevailing south-westerly winds for our survival. You have only to look at the climate of Northern Canada between 50^o and 60^oN latitude in the winter months (to say nothing of the same latitude range in Siberia!) to see how favoured we actually are in the UK as a result of our prime location at the eastern edge of the north Atlantic, with the added advantage of a warm Gulf stream lapping our shores.  

A new Ice-Age would be likely to slow or even stop the Gulf Stream in its tracks quite rapidly, resulting in a northern Scandinavian-style climate or worse within a few decades. 

There is a school of thought that suggests the current bout of global warming may of itself give rise to a ‘mini ice-age’ similar to that seen in Western Europe between 1600 and 1800 AD. This more localised phenomenon could result from the progressive freshening of the cold salty surface ocean waters that is already known to be occurring around Greenland. 

Salt water normally sinks rapidly to the ocean floor and this process is required to drive the so-called 'great ocean circulation' in the North Atlantic which maintains the Gulf Stream. Fresh water is less dense, and sinks less readily. The freshening process is already occurring quite rapidly due to the more extensive and rapid melting of northern polar ice cap, which now dwindles to virtually nothing by the start of  the Northern Hemisphere autumn each year.  There is also significant evidence that the Gulf Stream itself may be weakening. The progress of this circulatory switch-off could become quite rapid once a tipping point in ocean salinity is reached (see also this link  for details). Although the evidence is more anecdotal and hence less definitive, our UK weather does already seem to have become more extreme and drier, with pronounced hot spells in summer and more cold spells in winter. This is largely due to the increased prevalence of blocking high pressure, and the resultant changes in position of the jet stream, which give rise to so-called polar incursions as the polar vortex becomes disrupted. 

What would be the implications of a rapid cooling phase for everyday life in UK ?

Sadly, our existing UK housing stock is woefully inadequate to deal with 'normal' winter weather as it is, and the current energy- and cost-of-living crises are already threatening to plunge many of us into fuel poverty and cold-related health problems next winter….we have survived this one - so far - with the help of government fuel subsidies and cost-of-living payments. These are, however, now dwindling rapidly, auguring ill for next winter even if fuel prices do start to fall. This is a more immediate risk even if we assume the recent spell of milder winters continues unabated. We are already 'due' for a bad one and if it turns out to be '23-'24, much additional hardship is on the cards...

Continued world over-population and the consequent resource-depletion is already driving friction between nation states in many areas of the world. We have already seen the results of this on our own doorstep in the form of the Russia-Ukraine conflict, and this leaves us with an uncertain future even without any adverse climatological change. The additional burden of any significant rapid climate cooling could simply push our society over the edge.

Based on the real possibility of the above scenario, one has to ask the question: Is a moderate amount global warming really such a bad thing ?

One viewpoint worth considering in answer to this question suggests that we may actually be helping to ‘stave off’ the start of the next glacial period by our contribution to climate-warming. Although currently difficult to prove definitively, this idea does have some validity.

Given the disastrous potential consequences of a new full blown Ice-Age for our species (or even another 'mini' cooling event), which would far exceed anything even the worst-scenario global warming predictions have to offer, we might do well to temper our urge to reach ‘net zero’ by 2040 or before, given the drastic modification of our lifestyles which will undoubtedly be needed to achieve it.

We should, of course, continue our efforts to moderate our consumption of natural resources and limit our population growth – for our own and our children's sakes, if not for the health and well-being of the biosphere as a whole. My recent blog entitled “Are we alone in the universe” should put the need for this in context and help explain why we will probably only get one chance at making a success of it. Leaving global warming considerations aside, if we do not husband our fossil fuels more effectively we will simply run out. This would not only make air and road travel much more difficult, and severely challenge our ability to 'keep the lights on', but would deprive us of the essential feedstocks required by the chemical and pharmaceutical industries. 

There are good practical reasons for being flexible in our medium term strategy for reducing global warming:

1) Our society is already in a fragile and unstable state – to avoid ‘pushing it over the edge’, any changes should therefore be gradual, well thought out….and properly funded. Governments and the Energy Industry both need to ‘step up to the plate’ and be prepared to help consumers with the costs of the transitions, particularly the key task of retro-fitting of new heating systems and domestic power generation installations to existing properties. Our housing stock is after all a key national resource, of which we are all merely temporary caretakers, and the majority of individuals won’t be able to afford these costly upgrades on their own.

2) Many of the UK government's recently proposed energy supply solutions are by their nature longer term and won’t come on-stream until the late 2020s at the earliest. Nuclear Power installation in particular has an abysmal record of delays and cost-overruns, and should not be relied on to take up the slack much before the early to mid-2030s. The 'Holy Grail' of commercial fusion reactors is still decades away and may never happen at all. We urgently need rapid implementation of additional unused energy-generating resource to supplement our power grid, and domestic solar electricity generation is one which is still largely untapped (you can confirm this for yourself by looking at the house roofs in your own area). We must also be prepared to bolster our existing local gas and oil supplies through further development of these fossil fuels to help tide us over until the end of the decade. This will need to be done in a way that enables these reserves to be preferentially used locally in UK, rather than just sold away on the open market to the benefit of oil and gas producer's profit margins (see my blog entitled ‘The Energy Crisis – How do we Solve It ?’ for a fuller discussion of the possibilities).

3) We are currently experiencing a ‘perfect storm’ of adverse events which have all conspired to hit us simultaneously.  I would anticipate that the next 2-3 years will need to be spent ‘fire-fighting’ the worst consequences of these, in order to preserve our way of life as far as possible. This applies especially to the existential threats facing us in the West, particularly any fallout from Putin’s current so called 'special operation’ in Ukraine, which will require substantial ramping up of ordnance production if Ukraine is not to be eclipsed.

What conclusions can we come to from all this ? 

The principal message is perhaps best summed up as follows: 

Our climate is a capricious and unpredictable beast - we cannot accurately predict what it will do more than 2 or 3 days ahead, let alone decades or even centuries in the future. We should perhaps keep an open mind on the causes and progress of global climate change and, to coin a phrase, 'neither deniers nor acceptors be'. 

By all means let's do whatever we can as individuals and nation states to preserve precious natural resources and limit our demands on them, but let's not advocate massive and ill-thought out changes to the way we all live, just for the sake of the arbitrary 'line in the sand' of net zero by 2050. This target was, after all, created under very different circumstances to the ones we currently find ourselves in....

Pragmatism is the key - let's hope it wins out.

Viv

Revised 2/3/23