Protecting the Planet

(a WEA course)



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Week 2

Week 4

Week 5

Imagining Other Index Page  


Week 3 – Global Warming

1. Summary/overview:


Many observers believe that the most serious threat facing the earth today is climate change as a result of global warming.  The aspect of air pollution that is involved here is “the greenhouse effect”. When sunlight warms the earth, some of that heat is lost through radiation (bouncing off the earth) back into space. But there are some gases in the atmosphere that retain or reflect the heat back to earth – like the glass in a greenhouse. The effect, as noted below, was first discovered in the late 19th century.


Here we have another example of the precise balancing phenomenon at work in the ecosphere, since we are kept at just the right temperature for life to exist! (See the Gaia hypothesis). The most notable of these ‘greenhouse gases’ is carbon dioxide. In itself this is a harmless gas: we breathe it out all the time, when the oxygen we breathe in has been used in the lungs. (We could not live in an atmosphere of pure carbon dioxide, however). The balance of oxygen, nitrogen, carbon dioxide and other gases is just right for life.


However, human industrial activity - especially the burning of fossil fuels - including cars, has resulted in an increase in the amount of carbon dioxide, which has been carried up into the atmosphere and now keeps in some of the sun’s heat. Other contributing gases are CFCs (see notes on the ozone layer...) and methane: the latter is naturally produced by rotting vegetation, in ponds etc, but the amount of methane produced by human activity has actually increased with the industrialisation of farming, since cows’ flatulence contains the gas!  With regard to carbon dioxide emissions in the UK, levels are likely to be higher than government statistics suggest, and everyone agrees they are going to keep on rising so long as we continue to burn fossil fuel (especially coal and oil, but also gas). 


There are a few people who say there is a correlation but not cause and effect – but given some of the changes to weather etc, and the measured warming of the globe, something is causing the temperature to rise, and the vast majority of climate scientists are convinced it is due to the greenhouse effect. (See the section on ‘sceptics’ below).


2. Brief History of Climate Change (from Earthmatters, published by Friends of the Earth, Summer 2009, extra notes from Wikipedia):


1750 – 1800 start of industrial revolution – rises in average global temperatures are measured as from pre-industrial level.

1896 Swedish Chemist Svente Arrenhuis describes how greenhouse gases work and predicts a doubling of carbon dioxide in the atmosphere could increase global temperatures by 5 degrees.

1979 first World Climate Conference highlights CO2 levels.

1990 IPCC: Intergovernmental Panel on Climate Change (established by United Nations Environment Programme, and World Meteorological Organisation) 1st Report says human activity likely to be contributing to climate change. Details of working methods etc. of IPCC at: http://www.ipcc.ch/index.htm

1992 Rio Earth Summit or UN Conference on Environment and Development. 172 governments participate (2,400 representatives of NGOs, and 17,000 attended a parallel NGO Global Forum which had ‘consultative status’. Issues addressed included: patterns of production (toxic components such as lead in petrol, poisonous waste, radioactive chemicals), transport, air pollution, water, protection of land of indigenous peoples.  à Framework Convention on Climate Change (UNFCC). US had reservations about the Convention. Also: Convention on Biological Diversity (US did not sign), and other statements. Criticised for not recognizing need to fight poverty.


1995 2nd IPCC Report.


1997 Kyoto Protocol (building on the Framework Convention) signed by 192 parties (Canada withdrew in 2012 and US has not ratified it), to reduce greenhouse gas emissions ‘to a level that would prevent dangerous anthropogenic interference with the climate system.’ To come into force in 2005, and expire 2012.


2001 3rd IPCC Report.

2001 George W Bush opposes Kyoto ‘because it exempts 80% of the world from compliance and because it would cause serious harm to the US economy’.

2002 Larsen B ice shelf breaks up – a piece of ice a quarter the size of Northern Ireland falls into the Antarctic Sea.

2003 estimated 35,000 Europeans die in extreme summer temperatures.

2004 sudden cold temperatures cause cracks in Empire State Building.

2005 Hurricane Katrina hits New Orleans.


2007 IPCC Fourth Report says there is a 90% chance that human activity is warming the planet, and that global average temperatures will rise by another 1.5 to 5.8C this century, depending on emissions.”

2007 IPCC and Al Gore share Nobel Peace prize. Gore’s film/powerpoint presentation An Inconvenient Truth wins an Oscar. ‘Washington Declaration’ initiates a ‘cap-and-trade’ system to apply to industrialised and developing countries.

2008 Ed Miliband climate change minister, UK passes Climate Change Act (world first).

2009 Barack Obama becomes president and puts billions into renewables.


2009 ‘Climategate’ – e-mails hacked from Climatic Research Unit at University of East Anglia – scientists accused of distorting evidence and suppressing opposing data.

2010 Reports by Lord Oxburgh, Sir Muir Russell and Commons Science and Technology Committee find no malpractice, no withholding of evidence and no suppressing of dissenting views. Public trust in climate scientists drops from 60% to 40%.


2009, 2010: Conferences in Copenhagen Cancun


2012 Doha extension of (1997) Kyoto Protocol: 37 countries adopt binding targets (of which 7 have ratified), by July 2016 the number of countries adopting it rose to 66, but 144 are required for it to enter into legal force. EU and others agree to extend treaty to 2020.

2015 Paris Conference (UN Climate Change Conference – COP21: 21st annual session of the Conference Of the Parties to the 1992 Framework Convention). 196 parties attended. Agreement will enter into force when joined by at least 55 countries representing at least 55% of global greenhouse emissions.


2016 Earth Day – 22nd April: 174 countries sign in New York. Goal: to limit global warming to less than 2 degrees Celsius compared to pre-industrial levels. Parties will also ‘pursue efforts to’ limit the increase to 1.5 degrees. This will require zero emissions between 2030 and 2050. 


3. Response to a sceptic’s points on Global Warming as a ‘disaster myth’ (notes written in response to a paper by a student on one of my WEA courses):



It seems to me that a small group of ‘sceptics’ manage to have an influence that outweighs their number and their importance. It may be a bit odd to arrange these notes in the form of a ‘reply to sceptics’, but I was prompted to do so, a few years ago, by a detailed paper prepared by a student – until then perhaps I had been guilty of assuming that everyone knew how global warming worked!


I have also recently (2016) had cause to write to a local paper, because they have printed at least two letters from a local councillor who is a climate sceptic! The councillor’s argument was (in part) that changes in CO2 occur after changes in temperature, not before.

I wrote two replies, and the second (which they published) points out that no sources were given for this claim, while:


- ‘97% of climate scientists agree the world is warming as a result of our activities,

      mainly through carbon dioxide production.

- the Intergovernmental Panel on climate Change (IPPC) agrees, having scrutinised

            thousands of peer-reviewed studies.

- the Academies of Science of 34 different countries all signed the IPCC statement.

- the recent Paris agreement on climate change was signed by 194 countries.’


I added that ‘It is just nonsense to talk of a 'scam' perpetrated by mysterious 'interests' (which is what climate sceptics often say) - as it is no-one's interests to deny that global warming/climate change is happening. The World Health Organisation has said that 'climatic changes already are estimated to cause over 150,000 deaths annually.' 


My letter ended: ‘In my view it is irresponsible of a local paper to keep printing these false claims when across the globe people are already suffering from the effects of climate change.’ However, this sentence was not printed!


I hope this explains my concerns over ‘climate scepticism’!


I replied to various points made (i – viii) in the student’s paper as follows:


(i) There is not agreement among scientists that global warming is happening:


NASA has a graph on their website: http://climate.nasa.gov/keyIndicators/  which takes a mean temperature between 1951 and 1980 and plots the changes since 1880. It shows that around 1880 the temperature was 0.4 (degrees Celsius) below the mean, and now it is approaching 0.6 above. You can either say this is a 0.6 rise or I guess you could say it is 1 degree. I have seen other figures of 0.8 (Robin McKie – science editor of the Observer newspaper) or even more... and if, as many argue, the warming is a trend, then mean temperatures are likely to carry on increasing. There is a great danger if the upwards curve is, as Al Gore and others argue, exponential.


In his 2006 book, An Inconvenient Truth, Al Gore points out (p65) that scientists (he quotes Dr Lonnie Thompson, School of Earth Sciences, glaciologist, Distinguished University Professor at Ohio State University, and Senior Research Scientist at the Byrd Polar Research Center at Ohio) can measure both the past temperature of the earth’s atmosphere and the amount of CO2 in it, by examining ice cores. The CO2 is present in bubbles in the ice, and the ratio of different isotopes of oxygen (Oxygen 16 and Oxygen 18) records the temperature. He prints graphs (p64) which show the changes over the past 1,000 years. These show a dramatic and steady increase of around 0.5 degrees since the mid-20th century. Andrew Simms, G2 19th Jan 2017 says ‘temperatures have risen by almost 1 degree since 1880.’


There have been other fluctuations – such as the ‘medieval warm period’ – but this can be seen to have been a small, short-lived ‘blip’.


Perhaps the most striking chart, however, shows (p66-7) measurements in Antarctica going back 650,000 years. Here it is really clear that the changes in temperature and in CO2 concentration correlate very closely. You can see ice ages with periods of warming in between. During the ice ages the concentration of CO2 was below 200ppm, and this means large parts of the earth were covered with a sheet of ice a mile thick! The ‘warm periods’ show levels of up to 260ppm. ‘At no point before the industrial era did the CO2 concentration go above 300 parts per million.’


Current levels of CO2 are around 400ppm (parts per million) (Wikipedia, quoting National Oceanic & Atmospheric Administration). Note that this is (only) 0.04% by volume... [Note also: CO2 is essential for life, as the carbohydrates in the plants we eat are our primary source of energy; carbohydrates are made by plants through photosynthesis, which uses sunlight to convert CO2 and water into carbohydrates]. There has been a 40% increase (from 280 to 400) since the start of the industrial revolution in the middle of the 18th century. The level of 280 ppm held for 10,000 years before the industrial revolution. The present concentration is the highest in at least the past 800,000 years, and likely the highest in the past 20 million years (Climate Change 2001: The Scientific Basis). It is currently rising at a rate of approximately 2ppm per year – and accelerating (Peter Tans, Trends in Carbon Dioxide, NOAA/ESRL). 

These increases may appear small, but:

(a) only a few degrees (5 – 10) drop would produce an ice age, and Robin McKie, drawing on UN sources, says that an increase of 2 degrees would lead to 3 billion people suffering water shortages, and global food production being disrupted: http://www.guardian.co.uk/commentisfree/2010/dec/26/robin-mckie-carbon-emissions-up


(b) taking a global average, the 20 warmest years have occurred since the 1970s, and the 10 warmest years have occurred in the last 12 years (NASA) – the rate of change seems to be accelerating (see the point below on exponential growth). 2016 has been the hottest year to date, and each preceding year has shown warming.


However, an increase in global temperatures does not mean that everywhere gets warmer! There is a difference between weather and climate, and the weather effects of global warming are not easy to predict. However, Al Gore (2006) - see point 9 below - lists not just glaciers melting but also some places getting more rain, some having droughts, more hurricanes and other extreme weather events; the more frequent closing of the Thames flood barrier etc. The Association of British Insurers has pointed out that claims from storm and flood damage doubled between 1998 and 2003 (to over £6 bn) (sorry, I forget my source for this!).


Already Bangladesh suffers damaging floods, and these could become worse. In Britain the Thames Barrier has been raised more often recently (19 times in 2003, as against 3 times in 1983) – there is even talk of building another flood barrier. Just as worrying is the possibility that weather conditions will change so that there are more storms, hurricanes etc. Or, temperature changes (e.g. to the Gulf Stream which warms Britain’s coast line) would affect crops and even turn some areas to desert.

We have already had freak weather conditions in Britain – the floods in Cornwall, at Boscastle in 2004 for example – and scientists such as John Schellnhuber, of the Tyndall Centre, warn that things could get worse (Observer 7/11/2004). Apart from the damage, Schellnhuber and others argue that a point will come when insurers will not be able to pay for the damage: Insurers Munich Re believe that by 2060 the “cost of our changing weather will outstrip the total value of commodities and services produced by the global economy” The United Nations reports that the number of natural disasters has doubled over the past decade, and resultant economic losses have more than trebled. (Observer loc cit)]

A piece in New York Times (Sat Apr 15th 2012) asks whether the more variable weather we now see in the northern hemisphere is a result of climate change. In March parts of the US were very cold, after a freak heat wave – in France it was the other way round...

An IPCC report issued in late March (2012) suggested there is a link, and that climate change is leading to increased frequency of heat waves, and of heavy rainfall, and coastal flooding. The most likely explanation is that this is connected to the melting of Arctic ice, which has shrunk 40% since the early ‘80s – an area the size of Europe is now water, which does not reflect heat away from the surface as ice does. Dr Jennifer Francis of Rutgers University (quoted in the NYT article) says the question is ‘how can it not be’ (how can the loss of sea ice not be affecting atmospheric circulation). In particular, the heat is probably affecting the jet stream, producing ‘kinks’ which disrupt the normal temperatures.


Andrew Simms (loc cit) points out that in the Arctic in Nov 2016 the temperature was 20 degrees C above normal! Giant icebergs are breaking off in Antarctica.

However, some scientists dispute the link between extreme weather and climate change (loc cit): John R. Christy, University of Alabama, says it is simply down to the very dynamic nature of weather. Martin P. Hoerling, National Oceanic and Atmospheric Administration analyst, says what is happening in the Arctic is mostly staying in the Arctic, and some researchers are in too much of a hurry to establish a link between weather and human causes. But please note: these are arguments about the exact effects of climate change/global warming, not about the underlying trends. The same point needs to be made with reference to the criticisms of the IPCC report which claimed glaciers would melt quickly: this section was written by a separate group to the scientists who measured temperature change etc, and whose task was to speculate about the impact. No errors have been pointed out in the scientific summaries.

(c) the crucial point is that previous rises/falls (going back 600,000 years) have correlated very clearly with the amount of CO2 in the atmosphere, and the vast majority of scientists believe the major cause of the increased global temperature is increased CO2, not other factors such as: 

(ii) Other things, specifically sun spots are the cause of any ‘global warming’:

There has been a low level of sunspot activity between 2005 and 2010 – the lowest levels recorded during the satellite era. This means that the earth has been absorbing less energy from this source – recent (2011/12) calculations by the Goddard laboratory for NASA (cited on the NASA website – see References below, and in Hansen’s book) show about 0.25 watts per square kilometer. But the earth’s ‘energy imbalance’ (the difference between energy absorbed by the earth and energy returned to space) is 0.45 watts per square kilometer, that is: there is more energy generated inside the system than the amount that exits (a positive imbalance). Temperatures have been going up – but solar activity cannot be a cause of this. Solar activity varies over 11 year cycles – usually pretty regularly, despite the latest dip (see the next point).

(iii) Another key factor is the orbit and tilt/wobble of the planet:

There are of course natural cycles which affect the climate (including variations in solar irradiation, La Nina etc) – and no proponents of man-made climate change would deny this! The point is that these are natural changes, and pretty much predictable (because their patterns are usually regular), which work over long  cycles – whereas the pumping of CO2 into the atmosphere through burning fossil fuels is not natural, and can be shown to have affected the composition of the atmosphere dramatically in a short time:

The increase was first measured by David Keeling in 1957 (Hansen p 116) – and he also noticed a 24 hour cycle as trees and plants absorbed CO2 during the day and gave off CO2 during the night. He also found that there were variations near to human habitation – which is why he then made more measurements at a remote spot at Mauna Loa, Hawaii.


His measurements, which have never been refuted, (Robin McKie) show that CO2 increased from around 310 ppm to over 390 between 1957 and 2010. (*) There is no doubt that the levels will continue to rise unless major changes are made in the way energy is generated. Moreover, CO2 remains in the atmosphere for some time so that there is a time-lag: even if we start reducing our output now, the results will not be noticeable immediately.

Scientists believe it is important to reduce the level to 350 ppm to restore the energy equilibrium of the planet.

(*) This is a rapid change over a short period of time – and the rate of change seems to be accelerating. This is probably what is called exponential growth – like a compound interest savings account where the amount of increase each year goes up if the interest is left in. However, in nature exponential growth is very dangerous: nothing serious seems to be happening at first, but when the change gets more rapid we get to a ‘tipping point’ beyond which it is impossible to reverse the change. (The example I usually use to illustrate this is a pond in a garden: if weeds, say, are growing exponentially this means that the time in which it takes them to double the space they take up gets shorter and shorter. It is quite possible for weeks of growth to occur before the weeds cover half the pond, but they will then fill it entirely overnight! Your fish will suffocate before you have done anything about it.)

(iv) CO2 is a heavy gas and falls out of the atmosphere:

There is a CO2 or ‘carbon’ cycle – described by Hansen on pp 118 ff: plants, the oceans and the land act as ‘reservoirs’ for CO2 (plants/trees hold 600 billion metric tons [gigatons or GtC] primarily as wood in trees, soils contain 1,500 GtC, and the ocean holds 40,000 dissolved GtC – the atmosphere holds about 800 GtC as CO2).  Again, we know there are natural cycles such as the glacial to interglacial periods due to the movement of the earth in space. Also, when the ocean becomes colder it holds more CO2, so the atmosphere then holds less and this leads to more cooling. But when snow and ice melt, due to the earth’s changing orbit or tilt, then more CO2 is released, leading to more warming. These are examples of positive feedback – and Hansen says they account for nearly half the interglacial global temperature change.


An estimated 30-40% of the CO2 released by humans into the atmosphere dissolves into oceans, rivers and lakes which contributes to ocean acidification: we will deal with the various consequences of global warming later.

The crucial point, once again, is how human activity is interfering with these natural cycles.

(v) Other natural phenomena such as volcanoes affect the picture:

Yes Mount Pinatubo erupting in 1991 had an effect on global temperatures, by the aerosols it put into the atmosphere: it ‘reduced solar heating of Earth by almost 2%... this... however, was present only briefly – after two years most of the Pinatubo aerosols had fallen out of the atmosphere.’ (Hansen: Storms of my Grandchildren, Bloomsbury 2009, p 5). If there were a series of volcanoes continually erupting we would see a longer-term change.

Hansen in fact identifies no fewer than 9 ‘climate forcings’ – factors that affect the climate (p 6):

- CO2,

- other greenhouse gases,

- ozone,

- black carbon aerosols,

- reflective aerosols,

- aerosol cloud changes,

- land cover change,

- the sun

- and volcanoes.

Hansen gives precise quantifications for the different amount of effect each has... and concludes that CO2 is the most significant. This is neither a ‘myth’ nor what you call ‘denial’ (!) but scientific work based on real, detailed and thorough measurements.


(vi) Global warming is being unfairly used by such scientists as those at East Anglia University, to explain famines, when these are man-made:

(i) I am not aware of any environmentalists who would say climate change is the only factor in food shortages. UNEP (UN Environmental Programme) did suggest that the Darfur problem originated in climate change, and it seems to me incontrovertible that failure of rainfall causes crops to fail. Of course, civil conflict is a crucial factor as well in these crises, and in some parts of the world civil war has aggravated food shortage, (see John Vidal, Guardian 22.07.11, on the contribution of climate change + war to famine in Somalia) but would you want to rule out climate change altogether?

(ii) Please remember that ‘climategate’ originated when the computer at EAU’s Climate Research Unit was hacked into (by whom?) in order to release emails, which then were publicised by Fox News and other anti-global warming media. Eight committees have since investigated the CRU emails, and no evidence has been found of fraud or scientific misconduct. The scientific findings are not in doubt. The researchers did ‘fail to display the proper degree of openness’ in responding to queries about their data. I suspect they were bombarded with requests from would-be deniers and simply lost patience. Every time I encounter a climate-change sceptic I get the same feeling!


(vii) The film ‘An Inconvenient Truth’ was so full of errors that is was banned from being shown in schools:

The film has not been banned, and the court that was asked to ban it did not disagree with its central theme:

BBC (online) News 11th Oct 2007:  A campaign to stop the government sending DVDs to all secondary schools as part of a climate change package was started by a parent governor Stewart Dimmock (a member of the [right-of-centre] New Party). ‘The judge said he had no complaint about Gore’s central thesis that climate change was happening and was being driven my emissions from humans.’ He had reservations about 9 specific points which were not backed up by sufficient scientific agreement, including:


- the claim that polar bears have drowned because they have had to swim further (some

have died in storms);

- the claim that sea levels would rise by 6 metres in the near future (it would take

millennia said the judge);

- there was also ‘not sufficient evidence’ that global warming caused hurricane Katrina;

- ditto for the melting of snows on Mt Kilimanjaro, or evaporation of Lake Chad.


The judge said that the film should have guidance notes accompanying it to draw pupils’ attention to these points.  ‘The government has sent the film to all secondary schools in England, and the administrations in Wales and Scotland have done the same.’ A 60 page guidance document now goes with it.

The book has many, many examples of the effects of global warming, and it seems significant to me that the court ruled that only the specific ones cited were doubtful.

(viii) Polar ice is not melting:

You can check out details of all this on the NASA website, which has a ‘Global Ice Viewer’ that illustrates dynamically the changes that have been taking place - e.g. the annual minimum amount of Arctic ice (it shrinks in the summer and grows in the winter) has been decreasing by 11.2% per decade over the past 30 years, and in 2007 reached the lowest recorded level.

Greenland’s glaciers are losing 100 – 250 billion tons of ice each year and 400 billion tons has been lost from all glaciers per year since 1994, W. Antarctica has been losing up to 150 billion tons of ice per year). It seems to me that even if (as you claim) the ice is thickening  - which the NASA figures at http://climate.nasa.gov/evidence/ deny – still the area occupied by the ice has shrunk, and so less heat is reflected back into space and the warmer the planet gets (positive feedback).

Moreover, other changes have occurred in the oceans:

- sea levels have risen by 6.7 inches (17 centimeters) in the last century (approx 4 mm per year)– the rate of change  in the last decade has been double that of the previous century.

- the oceans’ acidity has also increased by 30% since the beginning of the industrial revolution (NASA – full references on the webpage; a change of 0.1 pH = 30% acidification)

- plankton, which control the carbon cycle, nitrogen cycle and part of the oxygen cycle (every second breath we take is of oxygen from plankton), are dying off as the oceans warm.

4. Who are the ‘Climate Sceptics’?


1. Al Gore in his book cites a study done by Dr Naomi Oreskes of University of California, which was published in Science magazine. She took a random sample (about 10%) of all the peer-reviewed science journal articles on global warming from the previous 10 years. There were 928 articles in the sample, none of which raised any doubts about the cause of global warming (though only three-quarters addressed the 'central elements of the consensus' and the rest were about specific issues not to do with CO2).  On the other hand, another study was done of all the articles in the previous 14 years from what were considered as the four most influential papers in the US (New York Times, Washington Post, LA Times and Wall Street Journal). Again a random sample was taken, amounting to almost 18% of the articles, and this time 53% gave equal weight to the 'consensus view' and to the opposition (sceptics/deniers) - thus giving the impression there was disagreement in the scientific community about the issue. (See more below).

He follows this up with points about how the tobacco industry adopted exactly the same tactics when the link with cancer was identified: a memo was uncovered from the Brown and Williamson Tobacco Company, written in 1960: "Doubt is our product, since it is the best means of competing with the 'body of fact' that exists in the mind of the general public. It is also the best means of establishing controversy." 


2. Lobbying:

The lobby group American Enterprise Institute, (AEI), an ExxonMobil-funded think-tank, has offered scientists and economists $10,000 each for articles questioning the report of the UN’s Intergovernmental Panel on Climate Change (IPCC)…. The AEI has received more than $1.6m from ExxonMobil, and more than 20 of its staff have worked as consultants to the Bush administration.

Robin McKie, Observer, 04.03.07(?), points out that those who contest the scientific consensus, e.g. Phillip Stott, Piers Corbyn, Nigel Calder, Nigel Lawson, have often got a political agenda. To deal with global warming, says McKie, quoting philosopher John Gray, will require government action and intervention in our lives – and probably bureaucracy – all of which is anathema to the sceptics, several of whom have pronounced pro-market views. (We are told, for example, that Europe will ban the inefficient fluorescent light bulb: I wonder if the Daily Mail will start a campaign to save it?!)

The names that McKie gives are of people who regularly can be heard on Today and seen on Newsnight  (so they cannot claim, as they do, that there is a conspiracy of silence over their views!).

Peter Wilby (New Statesman 16 Dec 2016 – 5 Jan 2017) says: ‘By my calculations, ten global-warming sceptics – including the Sunday Telegraph’s Christopher Booker, The Mail on Sunday’s Peter Hitchens, and the Times’s Matt Ridley – have regular columns in the main sections of national newspapers.’ According to Geoffrey Lean, environmental correspondent (formerly of Telegraph, Independent on Sunday and Observer) ‘There used to be four of us [columnists in national newspapers accepting the consensus]. But three of us have been sacked in the past 18 months.’ Only George Monbiot remains...