“The difference between weather and climate is a measure of time. Weather is what conditions of the atmosphere are over a short period of time, and climate is how the atmosphere “behaves” over relatively long periods of time”
“Climate is what you expect – weather is what you get”
Robert Heinlein (via Dame Julia Slingo)
Piers Sellars, who agreed to launch the Priestley International Centre for Climate (within which the research charity I work for, UBoC, is embedded) for us, but was, sadly, not well enough to attend, likened the Earth’s atmosphere to a Thin Blue Ribbon. All the greenhouse gases that are doing all the damage lie within that narrow strip.
Most diagrams designed to show how global warming works are misleading because they suggest a very deep atmosphere, but this is how big the gases around Earth would be if you scraped them all into a ball (the one on the right).
The size of all the water on the left is even more surprising – and we’ve been chucking crap and plastic into both for centuries.
Meanwhile, this is how much carbon-absorbing forest we’ve lost since humans first resorted to slash and burn agriculture. (A 2015 report estimates that the number of trees – not just forest trees – has fallen by approx 46% since the start of human civilization).
And we all know all about the extent of urbanisation and consequent pollution today.
Seen in these terms, it’s much easier to understand how humans could be damaging our seas and atmosphere to a point where they might no longer be capable of supporting civilisation as we know it.
Just in case this concept is new to you (can there still be anyone?) here is a short film which explains how man-made Co2 is rapidly warming the earth (on top of the very slow natural warming and cooling):
So – ultra simple summary (it’s actually fiendishly complicated):
ME: Practically all the earth’s heat comes from the sun. Small amounts of water vapour, plus minuscule quantities of carbon dioxide (and methane, actually, which is much worse though the effects of this are shorter-lived) in the Earth’s atmosphere trap this heat by reflecting it back to the surface.
YOU: Minuscule amounts of CO2? That doesn’t sound likely…
YOU: So CO2 is a good thing?
ME: The right amount is, yes. Without it, Earth would be a frozen desert.
YOU: But surely it’s been much hotter and cooler in the past?
ME: It has. The sun’s heat varies very slowly over aeons, because either the Sun is a teeny bit closer or further away (our orbit wobbles), or it’s a bit hotter or cooler itself thanks to long and short solar cycles, and that affects the heat reaching Earth.
YOU: So it’s true – the climate HAS always changed.
ME: It has, but very VERY slowly. Slow enough for life to adapt by moving to a new location or evolving.
YOU: Well, if Earth has been hotter in the past, what’s the problem?
ME: Two problems actually. The first is that today’s complex human society evolved in a period of calm, benign climate. So even if we had all the time in the world to adapt, we’d be looking at changes beyond contemplation today. We grow the wrong crops, rely on the wrong medicines. Our cities are in the wrong places. Our technology is wrong. We eat the wrong species. And there are probably too many people for a hotter, more turbulent planet too.
YOU: But we can adapt…
Me: No we can’t. Because of the second problem; speed of change. Last time anything like this happened it was due to a meteor. Ok, it happened much faster than what’s happening today, but in geological time-frames they both count as very rapid. The meteor wiped out most of life on Earth because only a few species were suited to the new conditions – the rest failed. Actually, this is already happening again today. Life on Earth is not at risk, but most current species are. And humans, with our fragile and fractious society, are the most vulnerable of all.
YOU: And we know all this for sure?
ME: Yes. The graphs of solar activity, and Earth’s temperature back since mankind evolved match pretty closely. (The story for CO2 is more complex – sometimes it increases due to solar warming, sometimes, as now, it causes warming).
YOU: Is this reliable science?
ME: Absolutely. But about 50 years ago these cause-and-effect graphs began to diverge.
YOU: How can that be?
ME: Well, the outside of the atmosphere is cooling, as expected. So we know the heating must be happening inside it somehow. But the Earth’s core is not warming and our physical heating activities are not sufficient to explain the anomaly. So it must be the atmosphere itself that’s trapping more of the sun’s heat.
YOU: Is it the water vapour perhaps?
ME: No, that hasn’t changed, and we can see it’s not to blame.
YOU: So it must be the CO2?
ME: Yes. CO2 enters the atmosphere naturally either very slowly due to weathering, or very rapidly due to a volcanic eruption or meteor strike.
YOU: Does that explain it then?
ME: No. The heat gain is much too great to be explained by weathering. (Actually, weathering can reduce greenhouse gas).
YOU: But you said volcanoes and meteors too…
YOU: You sure?
ME: Yes. But we have, however, been pulling carbon out of the ground, burning it, and releasing the gasses into the atmosphere on a grand scale for about, oooh, 150 years.
YOU: And this explains the warming?
ME: Yes, the sums match very well. The natural cycles are actually more complicated than I’ve implied – but it’s close enough for pretty much everyone who understands the process to agree that man-made emissions really ARE the problem.
YOU: So we need to stop leaking CO2 into the atmosphere right now?
ME: Yup, We have about a decade to halve emissions if we are to avoid a catastrophe.
YOU: Catastrophe. That’s a strong word.
ME: It is, but I don’t know how else you describe the loss of billions of lives, squillions of species and the collapse of society as we know it.
ME: Well, if you’re not convinced, please read on.
So how is this panning out today? Well, some people call this film below ‘alarmism’ – or even ‘warmism’:
If you think that’s ‘hysterical’ by both meanings of the word, and are not convinced that climate change (the direct consequence of global warming – both terms having been used since the phenomenon was first observed) is happening, that it’s serious, and that humans are largely to blame, may I humbly suggest that you ask yourself these four questions, which I’ve had to ask myself:
1) Do I really know enough about climate science to make an informed judgement?
Most people, even scientists who are not climate specialists, actually don’t (though many think they do), because, although simple in principle, this is a highly specialised discipline; an ‘A’ level or even an MSc in chemistry or physics may not be enough. If your answer is ‘yes’, then I’d love to hear your hypotheses, theories and evidence, so they can be tested – as all science should be. There are always minority views which eventually prove to be game-changers, but they do have to stand up to expert investigation, and until they do, science treats them with caution. (Would you like to be treated for a fractured skull with a homeopathic remedy?) So far most maverick theories in this field simply have not panned out as reliable, but the scientists’ door is always open.
If, however, the answer to the question above is ‘no’ then, like me, you will have to decide who to trust. So the next question has to be:
2) Who provided the evidence that convinced me?
Where did their evidence originate, and how reliable was it? Did it come from a qualified team whose work was tested by qualified peers, or did it come from semi-qualified ‘experts’ or, worse, from unqualified people perhaps with a political axe to grind?
If the former, fair enough – contrary to popular opinion, good scientists are (mostly) alert to new ideas, and would be delighted to be proved wrong in this case. They really would – believe me. But if the latter, then the third question has to be:
3) Did I simply choose, or accept, the theory which made most sense to me?
If so, this would have been entirely reasonable – it’s what all sensible people do – but it doesn’t follow that your ‘logical’ theory is in fact correct. Counter-intuitive science often proves to be reliable – as in heavier-than-air flight. Or the earth going round the sun. Or even evolution – in fact pretty much everything we found out using science not storytelling. Each was discovered thanks to someone getting curious, doing some experiments and, crucially, waiting until there was enough evidence pointing in the same direction before starting to decide what they might be looking at.
This article explains beautifully: “science always has to ask open-ended questions, because science is not a method for trying to prove something. Rather, science is a method for trying to learn what is true. It is a method for setting aside your biases, testing possibilities, and discerning objective reality. Thus, science must always go from evidence to a conclusion. It can never go from a conclusion to evidence. Indeed, if you start with a conclusion, then look for evidence to support that conclusion, you are, by definition, doing pseudoscience. This fraudulent strategy of trying to prove a belief while operating under the guise of science is extremely common among science deniers.”
And people do that because they have already decided on a theory they find comfortable. So finally maybe you need to ask yourself:
4) Do I need to challenge my ‘personal paradigm’ (see below) – step away from my comfort zone and try to assess the evidence before me as a scientist would; dispassionately and honestly (as, eventually, these scientists, meteorologists and political commentators did)?
If you think you know something that mainstream science does not, or if you favour the views of maverick scientists who mainstream scientists question, first of all; beware the Galileo Gambit. This can be summarised as:
They laughed at Galileo, and he was right. They laugh at me, therefore I am right.
And also bear in mind that it was the Church who oppressed Galileo, not his peers – who largely agreed with him. It’s tempting to back the little guy just because he’s the little guy. (We all back the David against Goliath). But the little guy might just be plain wrong.
If you want to understand the science properly, please follow the links below. They challenge the more common maverick views that I list in the next section.
Google will find you many other sites which support the mainstream or ‘consensus’ view – as well as some initially convincing sites which say differently.
Unfortunately, it is often these maverick sites which are referenced by journalists from – especially – the Mail, the Express and the Telegraph in the UK, and many other ‘libertarian-minded’ media outlets around the world.
Remember, science does not care about your politics. It just is.
The sites I’ve linked to below are run by and/or monitored by professional scientists whose views are informed by sophisticated (and cross-verified) models, verified data, and peer reviewed opinion. Most of the others – including a terrifying slew of YouTube and similar sites – are run by people who do not do their own field research or publish in reputable journals, but have just enough expertise to appear to find technical fault with the mainstream view, for one reason or another – and it’s usually politics, if we are honest.
This, below, will probably have had a lot to do with it: Many people just don’t understand what the scientists are saying, and think, for example, that they are admitting to being biased (bias), or fraud when they are simply referring to the processing of data (as in ‘manipulating’):
Term | normal meaning | what scientists mean
Examined in any depth, these criticisms are usually based on what are now old chestnuts – misunderstandings or mischief which has long since been corrected by authoritative explanations (see, again, below). But it can be tricky for the lay visitor to untangle the rights and wrongs, facts, faiths and fantasies of these arguments – not least because the maverick nay-sayers always challenge every correction – and usually vehemently, and come up with impressive-sounding ‘experts’ to back their views.
Equally confusingly, proper scientists nuance their opinions, and typically use technical jargon supported by complex graphics. Maverick sites seemingly display just as impressive language and graphics as the mainstream ones, but, tellingly, they seldom display properly nuanced opinions, while frequently intermingle ideological rhetoric with their science. (Yes, I do this a bit here, but I’m not a scientist, and I’m not asking you to trust me. I’m asking you to go read the reliable science and trust that).
Each ‘side’ claims the other is doctoring the data, so you need always to follow rebuttal and counter-rebuttal, back and back, until you encounter something which is clearly reliable – i.e peer-reviewed by people who fully understand and can evaluate and replicate the experiments, and then published in an authoritative journal (not a politically-motivated blog or YouTube) – as you always will if you look hard enough.
There are those who say the peer-review process itself is flawed, but what else do we have? Religious faith? Pig ignorance? Google?
No. If you find yourself dismissing mainstream science out of hand, then you need to go somewhere quiet and have a good long think. Or go and actually meet a few climate scientists. You’ll soon see that they are genuine and very very worried people.
Society simply has to go with the best-informed opinions we have, in a spirit of productive debate – and perhaps with a bit of common sense. If that’s ok with you, please read on.
Some people fervently believe that climate science is like a balloon that can be popped by one error, disproven theory or damaged dataset. Not so. It’s actually more like a bramble thicket; rooted in the soil of basic physics, constantly growing and branching, and composed of tough, thorny, intersecting theories which all support each other. (This is called ‘concilience‘ in the trade).
You can cut out a great many stems without materially changing the thicket. But it will surely pop any maverick hot-air balloon which drifts into contact!
Meanwhile, many on the majority side love to claim that climate science is ‘settled.’ I never do because this implies that all the theories are fully proven – which they are decidedly not – though I think we can say, post Paris, that the debate is, finally, settled.
Climate science is actually relatively new. The basic principles have been known for centuries, but the discipline did not get going in earnest until 1984, when Farman, Gardiner and Shanklin discovered the hole in the Ozone layer and everyone started cramming on their thinking hats.
Like all science, it does and will evolve, but this is not evidence of incompetence or corruption: The evolution of ideas and theory is actually healthy and necessary. (Think of the advance of medicine – and how confident we are today when we slice open a patient).
It would be fantastic if new, robust discoveries could somehow let us off the climate hook, but, sadly, nearly all recent data has tended the other, more scary way.
And if you’d like to keep up to speed with the latest developments presented, usually, in layman’s terms and think you can deal with relentless bad news, just follow Climate Geek, (of which I am one of the admins).
Truth, Lies and Websites
In spite of the above, I am myself not professionally qualified to judge the veracity of the ‘majority view’ websites below. I have done my best to be critical, but this blog can only be my personal opinion – restricted, for sure, by my own paradigm. I will, however, gladly do my best to explain my opinion if you ask (hey – you may even change my mind!) – and I can report that climate experts who I know personally ‘tend to’ agree with me – and that caveat is the typical caution of thoroughly professional boffins!
So here are the websites I ‘largely’ trust.
*(The term skeptical, applied to science, really just means ‘thorough’ because good scientists are always sceptical of both their own and others’ work. So Climate ‘Skeptics’ might be better termed ‘Contrarians’ if they hold an evidence-based minority view, or ‘Deniers’ if they flatly refuse to accept mainstream science because they don’t like the implications. I avoid the latter term, though, because it has unfortunate connotations, and favour maverick here).
Here are some of the common objections to the mainstream expert view – there are scores more which you’ll find on the maverick links, very few of them even slightly convincing – to me, anyway:
MYTH: “There’s been no warming since 1998.“ This is akin to seeing a wave falling back down a beach and concluding that the tide is therefore not rising. Also, the readings which suggested no surface warming, as measured by satellites (whose data is generally considered to be none too robust) on which this view was based, take no account of deep water heating. New evidence suggests major heat (denser water / more energy / heat) has been building up in the ocean depths throughout this period. 2015 was the hottest since records began, and the years since have been increasingly chaotic and alarmingly warm. More
MYTH: “The climate has always changed.“ Yes it has, but much much much much much much (is that enough muches?) slower than we’ve seen in the last 150 years (the only rapid changes we know of were from asteriod strikes, and there ain’t been none of them recently. More
MYTH: “It’s Volcanoes.” According to the US Geological Survey, human activity produces as much CO2 in a few days as all the Earth’s volcanoes produce in a year. Also annual human production of CO2 is roughly the same as one or two supervolcanoes. The last supervolcano eruption was about 70,000 years ago.
MYTH: “It’s the sun.” No it’s not – we can track solar activity and wobbles in the earth’s distance from it (which are the two main variants) and the climate on Earth back many thousands of years, and the graphs match pretty well – until the Industrial Revolution, when they begin to diverge strongly. The sun is actually in a very slightly cooler phase at the moment, and the upper troposphere (beyond the greenhouse gases) is, as we’d expect, cooling. Yet inside the ‘greenhouse’, the temperature is rising. More
Here is a beautifully animated graph which explains all the ‘forcings’ very nicely indeed.
MYTH: “It’s water vapour” Nope
MYTH: “Antarctica (and/or the Arctic) are gaining sea ice.” No they are not. There are some small regional or seasonal gains, but these can be explained by melting land ice causing changes in salinity, currents which isolate Antarctica from the warming oceans, and the hole in the ozone layer (which is still there). Like a pot on a stove, global warming increases the energy in the system, which then presents as increased turbulence in both sea and air flows, exacerbated by temperature differentials between air and water at different latitudes (the poles are warming faster than the equator) – see below. More
MYTH: “We had more snow/rain/wind here than usual etc.“ See above. For example the Jet Streams (there are four) are slowing and meandering more because the poles are getting warmer compared with the equator. This can cause unseasonally long periods of unexpected weather – so basically the local weather being worse (or better) does not mean the average temperature of the planet is not increasing. More
MYTH: “We’re approaching a mini Ice Age /Scientists told us in the 70s the world was going to cool.“ Before the full effect of manmade Co2 was properly understood, a few scientists did predict cooling due to solar dimming. In fact we are indeed approaching a Solar Minimum caused by reduced sun spot activity, and without human emissions we should be in very slow cooling phase – circa 0.2 deg C per 1000 years. This cyclical phenomenon was indeed associated with the last mini ice age, from about 1645 to 1715, but other factors were also in play then, and thanks to global warming no cooling is predicted inside the greenhouse gas layer this time. (Beyond the layer, the troposphere is, as predicted, cooling).
MYTH: “Sea levels are not rising.” Yes they are, and the latest data suggests a much faster rise then previously predicted. More.
MYTH: “CO2 is not a pollutant.” In this case it is. Just as the definition of a weed is a plant in the wrong place, so the definition of a pollutant is a chemical (or noise, or light or anything), in the wrong place. And though we do need a balanced amount of CO2 for plants to grow, too much is certainly pollution. More
MYTH: “CO2 is a only trace element – at 400ppm it can’t be causing a problem.“ A very reasonable assumption. But wrong. More. And here is a very good 24 minute lecture by Richard Alley if you want chapter and verse (and do check out his others on youtube too).
MYTH: “CO2 rise follows temperature rise, rather than causing it.“ Yes, in the past this has happened, but now there’s so much CO2 in the system it is actually trapping heat. Last time there was this much CO2 it was indeed caused by warming, but very very slow warming, ‘forced’ by very very long solar cycles. More
MYTH: “Manmade emissions are dwarfed by natural emissions.” True, but natural CO2 is reabsorbed by planetary cycles at the same rate it’s released, so is not increasing overall. The only change is the arrival of man-made CO2, which plants and the sea can’t absorb fast enough. (And meanwhile, sea life is in major trouble because of the build up in carbonic acid). More
MYTH: “CO2 is good for plants, and animals can adapt.” Not in the time available they can’t. Very small changes in temperature and moisture can have huge effects on microbes, soils, roots, pollinators, pests and diseases. Our ecosystem services (oxygen, clean water, plants etc.) are vulnerable, and the consequences are severe for bugs – and therefore us. More
MYTH: “Temperature measurements are unreliable” (sometimes expressed as “scientists are fiddling the measurements”). Almost anywhere you choose to put a thermometer on the surface of the Earth, there’s going to be local factors that need to be taken into account – such as the heat from a city or ships’ engines. Adjusting for this is not cheating, it’s good science. See here. Satellite data is more problematic, which helps to explain how ‘the pause’ obtained traction, but once properly processed, this data largely supports the surface evidence. See here.
MYTH: “It’s actually atmospheric pressure that’s causing the warming.” Absolutely not.
MYTH: “You can’t take the average temperature of a system as complex as the biosphere” Well, it’s not easy, but thanks to modern computer modelling we think we can. More.
MYTH: “Climate models are unreliable.” They may not be perfect, but they’re as good as the millions of other models on which most of modern life depends today. There were some minor discrepancies between projections (they are not predictions) made by early climate models and real world observations, which some view as a smoking gun, but in fact this was just normal developmental science in progress. Today the models largely agree with each other and are considered to be robust (and this is not because they’re all based on the same, flawed, data). Bear in mind that any lack of accuracy could just as easily be masking even worse trends (as recent observations do suggest). “Uncertainty is not a weakness. Understanding uncertainty is a strength, and a key part of using any model, including climate models.” – http://www.demystifyingclimate.org/ More
MYTH: “One degree of warming means nothing when temperatures vary by tens of degrees every season.” It is not one degree in any given place that’s the issue. It’s one degree added to the temperature of ALL the water and gas in the biosphere. That’s a LOT of warm (8 zetajules-worth?) – creating a more energetic, turbulent and chaotic system which holds a lot more moisture to fall as precipitation when the conditions dictate. More
MYTH: “The Hockey Stick was a fraud.” No. It was a best attempt, and it’s stood up very well to scrutiny. More
MYTH: “It’s a political plot (or the UN are promoting Communism).“ The IPCC volunteers (there are thousands) merely sum up a vast quantity of authentic science, and offer a range of scenarios for others to base decisions upon. If anything, political pressure and the need for agreement would tend to make IPCC reports more conservative than alarmist. It actually does turn out (see below) that the solutions to climate change can look at first glance more like socialism than neoliberalism, which annoys the right and makes them attack the scientists, but it’s not communism, or even conventional egalitarian socialism, and remember that science is not politics. Don’t shoot the messenger. More
MYTH: “There is no consensus / There are many thousands of ‘contrary’ scientists.“ Not properly qualified climate scientists, whose work is tested by equally well-qualified scientists, there aren’t. More
Boffins in the Back Room
It’s crazy to suggest that climate scientists are somehow too dumb to have thought of these objections, which tabloid writers and bloggers love to claim a child could explain to them. But some of the other ‘ad hominem‘ attacks need a bit more investigation:
MYTHS: “Scientists are only in it for the money / It’s just a kind of academic ‘group-think’ / Warmist ‘experts’ need to shut down the debate, so they attack anyone who questions them.“
Let’s take these one by one.
Obviously, if you were only in it for the money, there would be FAR more reward in researching (and/or promoting) ‘business as usual’ than climate change, as many journalists and politicians (and even a few scientists) have found. The bottom line is that for the ‘contrarian/refusenik’ position to hold water, thousands of senior scientists around the world would have to be either stupid, or corrupt, or both.
There is just too much data and expert interpretation (imbued with a healthy level of internal argument I’m glad to say) for the consensus to be explained as mere fund-wrangling. And as for being agents of government – most western governments would greatly prefer easy ‘business as usual’ to difficult decarbonisation, so there’s no incentive for money chasing there either.
As we saw above, the consensus really does exist. Ask any scientist who spends his or her time at conferences, emailing and skyping other experts around the world, reading and reviewing papers, hunting for data and querying those who’ve published it – as happens every day in my own department. (We have 5 IPCC lead authors at Leeds – one of them is my boss – along with various other contributors, and they are all decent, honest, sceptical – yes – that’s in the very nature of scientific enquiry, and also very worried people. And no, I don’t speak for them).
The second is sometimes termed the ‘Galileo Gambit.’ To expand on the above, it goes something like this: Because Galileo railed a lone voice against the consensus view, and was proved to be correct, we should champion lone voices over majority opinion. This is plainly stupid. If taken seriously, we’d have to champion the likes of Andrew Wakefield, David Ike and many other dangerous Pseudoscientists, alongside the infamous classicist and journalist (not scientist, note) Christopher Lord Monckton. More importantly, Galileo was defended, and eventually vindicated, by scientists against a religious political power base: The Catholic Church. Nuff said?
No. The scientific method is designed precisely to prevent group-think – and it does. The whole idea is to find fault with each other’s theories – it’s how the system works.
The last is the most silly. There is a big difference between pointing out that someone’s theory is bad science and shutting down the debate (though no doubt it does feel like you’re being shut down when you find your cherished theory does not stand up to expert scrutiny). Science IS debate, by definition. A few scientists are now speaking out (Michael E Mann most notably – and he has good reason), because they know that the consequences of their work not being taken seriously will be horrendous for mankind. And various writers close to scientists are working hard to explain the science and its consequences, and to explore potential solutions. But that’s NOT shutting down the debate, it’s promoting it.
To be clear, the basic science is accepted by the vast majority: Greenhouse gases cause global warming, and global warming drives climate change. CO2 is a greenhouse gas, and humans are emitting it on an unprecedented scale. And this is making a contribution to the measured warming. There is, it’s true, a range of opinion about how much of a contribution humans are making – so the degree of risk is not universally agreed. The IPCC position, expressed by a range of projections (not predictions, note), is roughly in the middle of this opinion – obviously – because it’s a summary of that opinion. And that’s as good a definition of consensus as anyone should need.
So. At a risk of being overly simplistic perhaps we can identify four basic positions:
A (for Antis?) There are a tiny handful of qualified scientists (I don’t include among these all the chemistry teachers and mining engineers and tv weathermen who believe they are experts on climate, but are more obsessed about the size of government or something – and who happen to be good at making YouTube videos), with honestly-held maverick views, which the majority are currently not impressed by but which could change the consensus one day. But only IF they can produce evidence / data which can be independently replicated, as all science must be, by definition.
B (for Blasés?) Then there are a few more relatively relaxed climate scientists who are not expecting an apocalypse tomorrow, but who still believe we should decarbonise. These are sometimes called ‘Lukewarmers.’
C (for Conservatives?) The IPCC ‘position’ (endorsed by all major scientific institutions, nearly 200 governments in Paris, and, now, a huge number of corporations – including fossil fuel companies) comes somewhere here. This group is known by the ‘Antis’ as ‘Warmists.’
D (for Doomers?) And finally there are the many deeply worried scientists at the other extreme, who think the situation is already very serious, and that the IPCC position is a dangerous compromise. Now, I can’t give you a percentage, but my genuine feeling is that this is by far the largest group. And that it’s growing – as researchers increasingly find that climate change is happening now, and even faster than the last IPCC summary, AR5, anticipated.
Given that we know that there’s about a 30 year lag in the climate system (so CO2 emitted today will continue to warm the Earth for three decades even if all further emissions were stopped tonight), the precautionary position has to be the only responsible one. (I should mention here that a collegue recently explained that there would in fact be a significant drop in temperature if we did suddenly stop all emissions, but the lag effect would still be significant and persistent).
So given that the IPCC is the only official summary of the science we have, it has to be on IPCC projections that policy must be based.
Arguing against this makes no sense. Decarbonisation is almost certainly a good idea for any number of reasons other than the climate, and if creatively pursued can also give us a healthier economy – as we shall see below.
Global Warming (and Tipping Points)
Some say that the near 1o rise measured since the beginning of the Industrial Revolution is trivial, but actually 1o (which translates to much bigger rises and reductions locally due to the changes it causes in air and sea currents, see above) can mean the difference between water or ice in one place or another. The presence or lack of ice is one of the key factors in the climate system, so this small change can have major impacts not only on local weather, but also on the rate of climate change – especially in terms of potential tipping points (see the ‘albedo effect‘, for example). Remember that it’s the local rate of change that puts pressure on local ecology (small creatures can be very moisture and temperature sensitive when breeding, especially microbes), and therefore on us, as much as the global average change, which affects things like sea level rise. (Melting water ice is not a massive problem of itself because ice displaces water – it’s the land ice that’s the worry – along with the greater bulk of a warmer ocean).
Various projections have been made for the future.
Many believe that 2o (the unofficial target throughout the period between the Copenhagen and Paris talks) is already too hot, risking further damage to ecosystems, limiting agriculture and so causing migration, increasing extreme weather, raising sea levels dangerously, disrupting and even reversing sea and air currents, and possibly even increasing seismic activity due to the release of continents from the weight of ice sheets. All these have happened before, of course (there used to be crocodiles swimming at the North Pole) but then we did not have a complex global infrastructure depending on no change.
The commitments made just before the Paris talks are estimated to deliver about 2.7o of warming, which is certainly too hot for comfort. Of course, at the last minute, the Paris accord did do its best to commit the world to 2o, and even added an aspiration towards 1.5o, which would still be too hot to avoid major problems, but is perhaps achievable – if radical action is taken by every government in the world over the next couple of years. And here is my boss Professor Piers Forster on what 1.5 needs to look like here.
But what happens if the world fails to act?
Here again is the scary map published by New Scientist in 2008 which I used in The Urbal Fix, with its prediction of what 4o could look like by 2050: Much of the middle band of the planet has become inhospitable, so humans are having to migrate north or south. Nothing has come along since seriously to dispute this scenario.
But, as we heard in The Urbal Fix, many now believe that the rise (if no action is taken) could be as much as 6o , and as Jonathan Porritt says in the film; “6o would be a death sentence for human civilisation. That doesn’t mean to say there won’t be lots of human beings left over after a 6o rise, but I assure you, they won’t be having much of a time.”
And, of course, if certain tipping points are exceeded, it could be even worse than that. Much, much worse:
“ A [small] rise in ocean temperature would melt the ice caps, and cause the release of large amounts of carbon dioxide from the ocean floor. Both effects could make our climate like that of Venus, with a temperature of 250 degrees.” Professor Stephen Hawking
Now, I blame no-one for starting with an opinion that this simply can’t be happening – I thought the same myself for many years. It is just so counter-intuitive that suspicion must be the default position.
But the truth is that major disasters do occur, and they can be huge – witness the poor old dinosaurs. Science is now largely in agreement with Walt Disney – it was indeed an asteroid, and the CO2-induced warming caused by that impact – (the dust did cause an initial global winter, but did not remain in the atmosphere for long), was about the same as is associated with a doubling of energy use from 2009 levels.
IE: Roughly what happens if we fail to implement the Paris Accord, and continue with ‘business as usual.’
IE: Jonathan Porritt’s 6o scenario.
So, frankly, it’s not surprising that so many people are fighting tooth and nail to deny this is happening – after all, as TS Elliott wrote to Tennessee Williams; “Humankind simply can’t bear too much reality.”
But evidence is evidence, and we have plenty.
I’d love to report that my detailed and pretty much constant enquiry into this topic over the past 6 years had reassured me. But it hasn’t. Unfortunately it really does seem we are at the lip of a crisis, and, worrying though that is, climate change is not the only challenge we’re facing.
There are in fact three problems caused by the way we’ve been consuming our home planet. Chief Scientific Adviser to the UK Government, Professor Sir John Beddington, called them The Perfect Storm – a veritable dangling trident of threats; climate change, economic debt-rooted chaos, and rapidly dwindling resources (especially oil, key minerals like phosphorus, clean water, healthy soils) – losses exacerbated by the pollution of what remains. This diagram shows the extent of the problem:
(The green disc is the ‘safe area’ – the red shows how far we have moved outside it)
Now. We need to be clear, the major threat from climate change is not extreme weather or sea level rise per se, (these could in theory be resisted with existing, if massive, engineering technology) – it is food security, because in spite of all the carbon-emitting, oil and chemical-consuming, polluting new technology, the global food system remains as always totally dependent on a healthy ecological system, something that engineering, even GM, can only hope to tinker with.
These are the countries whose food is most at risk from climate change:
And these are the countries whose emissions are causing the problem – almost a mirror image (and if that doesn’t ask a moral question I don’t know what would):
(Note that India and China, whose emissions are often cited as being a reason why the west should not bother to decarbonise, are shown white. This is per capita emissions – surely the only fair bench-mark, so even with recent new coal-fired power stations, they’re not even on the scale).
Given that there’s a direct link between climate change, food prices and conflict – (there is increasing evidence that the current turmoil in the Middle East has its roots in climate change – also here – as much as in religion, colonialism, corruption and the rest),
(from Prof Tim Benton)
we seem to be looking at a causal chain which goes something like this:
Neoliberalism (the ideology of unregulated markets) > market failures (aka ‘externalities’) > environmental degradation and collapse > food scarcity > starvation > local social unrest > local war > migration > non-local unrest > regional war > further pressure on remaining ecology > etc.
Which is why the New Scientist map above is so scary.
Now, let me say again in big letters, in case you are feeling a little queasy just now;
WE CAN AND WILL FIX THIS!!
But to know what to do, we have first to go back to the beginning, to understand how we got here.