Dr. Richard Milne

that that bring a sense of security to our society. Dr. Milne examines four of these global-scale threats and asks the question of whether we will be remembered by generations to come for our willingness to stand together to combat these threats, or for our ‘business as usual’ response, ignoring all of the warning signs.

The mythical four horsemen of the apocalypse were Death, Famine, War and Pestilence.  Death of course is ever present, but the other three struck fear into human hearts because they could ride in swiftly and take thousands of lives.  Yet society always survived these visits, because the horsemen always ride off again.  Wars end, famines recede, and epidemics run their course.  In the modern world, not much has changed.  War is country-hopping in the middle east, Pestilence whispers “bird flu” into the ears of bored journalists, and Famine has reinvented himself as “Economic Crisis”, because money seems to have replaced food as our basic need.  They may take some of us, but they will never take us all. Indomitable humans!

The real threats to human society are long-term.  They arrive not on a charging steed, but at snail’s pace, like lumbering but unstoppable zombies.  They are discussed, yet never seen as urgent.  However their threat is ultimately far greater than that of the original horsemen, because the damage they do is likely to be permanent, or at least far harder (and slower) to reverse.  When the history of the current century is written, the main story of the early years will not be wars, terrorism and credit crunch.  It will be about whether or not we dealt with these threats.  Meet the Four Tortoisemen of the Apocalypse.

Tortoise 1: Climate Change

Forget polar bears!  If climate change is allowed to run unchecked, the conditions that allowed civilisation to form will disappear, to be replaced by a far more unstable planet.  Humans may survive, but the comfortable lifestyle of today will be a distant memory.  Man-made climate change is accepted by all competent scientists, but doubted by the public for two reasons.  One is that incredibly sophisticated and well-funded propaganda campaign called “climate skepticism”.  The other is that no sane person wants climate change to be real, and certain types of people form their beliefs based on what they want to be true, rather than what the evidence says.  This makes them willing to accept, uncritically, even the most idiotic arguments of climate “skeptics” while rejecting the clear and obvious evidence that climate change is already happening.

Tortoiseman 2: Overpopulation.  

The same sort of people are therefore likely to reject other inconvenient threats like overpopulation.  The facts are undeniable:  Earth’s population is growing exponentially, doubling every 40 years. Agricultural innovation tries to keep pace by increasing food production, but the increase is at best linear, and hence starting to fall behind.  If you keep adding people to a finite planet, then sooner or later large numbers of them will starve, even if no floods or famines occur; the only argument to be had is how soon.  Overpopulation deniers, however, insist that we can grow our population forever. Some of the deniers are those with devout religious beliefs about procreation, but perhaps more dangerous are the right-wingers, whose credo is that all human needs can be met by economic growth. This is an illusion, created by uneven wealth distribution and the fact that lack of money is the only cause of hunger here.  In reality, economic growth moves resources around and can create jobs, but can’t magically grow a finite resource like farmable land area.    The solution to overpopulation is to educate young women and give them control over their family sizes, but most of the public, just seem to view overpopulation as unimportant.  Like climate change, it is seen as happening elsewhere, if at all.  No-one links it to immigration; if they did, opinions might change.

Projected World Population 1800 to 2100 (Source: Dr. Alex McCalla & UN FAO)

Tortoiseman 3: Ecosystem Destruction.  

This is a problem everyone knows about, but most people either don’t care, or perceive it with sadness rather than fear.  A forest lost here, a species lost there, it’s a shame but why worry when there’s a war going on and people dying?  Occasionally the link is visible – for example most people are aware that the loss of bees will impact heavily on food production, yet food production relies in subtler ways on innumerable biological relationships.  Wasps pollinate some flowers like raspberries, and can pick off pest species too.   In a functioning ecosystem, food webs create checks and balances: when one species becomes more common, its predators and parasites follow suit and reduce their numbers again.  These processes can control pests of agriculture without recourse to insecticide sprays; modern monocultures do still allow booms of pest species but it would be far worse if their natural predators disappeared.  This is an example of what are termed “ecosystem services”.  Plants purify groundwater.  Fungi and other soil organisms recycle nutrients.  Forests and bogs trap rainfall and reduce the flooding from sudden heavy rainfall events.  The fish we eat from oceans sit near the top of marine food webs which could collapse due to overfishing, ocean acidification or other pollution.  We rely on a functioning ecosystem, both locally and globally, to meet our food and other needs.  Too few people realise that to grow food you need soil, and that modern agricultural methods are eroding soil all over the planet.  Yet those who speak out against continuing ecosystem destruction are labelled as sentimental, treehuggers, enemies of progress, the list goes on.  Any one of these alone would be threat enough, yet each makes the others worse.  More people means more carbon emissions.  More warming means more farmland lost to deserts and rising sea levels.  Lost farmland and growing population forces people to cut down forests, realising more carbon and degrading stressed ecosystems still further. Meanwhile a growing population forces us to flog more food out of existing land, pouring on fertilisers and pesticides because our natural allies in soils and pest predators have been reduced or removed.  Yet these chemicals come with their own carbon footprints, and damage the ecosystem still further. Climate change creates extreme weather, destabilised ecosystems remove biological defences from floods and plagues of pests.  It’s a vicious circle and brings us to the fourth Tortoiseman, riding shotgun for the others.

Tortoiseman 4: Food Security

Of all of these, this is the one likely to impact first, and most, on our comfortable lives in the developed world.  Overpopulation would mean a progressively smaller share of global food production if things are divided equally, and as they are not, it will instead mean more rapidly shrinking shares for the poorest.  Yet the developed world is not immune.  Bouts of extreme weather have destroyed wheat crops in sufficient quantities to push up the price of bread, yet climate change has barely shown its teeth in the past ten years.  Far worse is to come.  All it will take is a coincidence of several major extreme events, causing crop losses all over the world, to bring us to a point where suddenly we can’t guarantee enough food for everyone in (say) Britain.  It may only last a week or two, but a crisis like this will change forever how we see our lives and what threatens them.   Finally we will start to realise, as a wise man once said, that you can’t eat money.  Yet once again, the real problem lies further ahead, not with the unpredictable present but in a future where we know food production will get more and more challenging while the number of mouths to feed increases.  This is a problem that won’t go away, unless we deal with all these problems now.  We cannot leave our descendants to face the horrors of mass starvation.

We all want to think that human civilisation is indestructible, and that the way things are now is how they will always be.  It is human nature.  Yet great civilisations have fallen throughout human history, very often because of environmental change that they themselves had caused.  Today mankind will stand or fall as a single species, because we are all now interconnected and what we are doing to the environment affects everyone.  We are also perhaps unique in that we understand completely the things that we are doing and how they threaten are future.  The challenge, therefore, is whether we can come together to turn back the Four Tortoisemen of the Apocalypse.

Dr Dave Reay

I like gas. Each morning it is the source of instant heat for making my coffee. Each winter’s evening it is the roar in the boiler that spreads warmth through the house. At work too, this energy-packed gas is a daily focus of our climate change research, but it’s there that its darker side often comes to the fore. Natural gas consists almost entirely of ‘methane’ and, as methane is a greenhouse gas 25 times more powerful than carbon dioxide, it presents both problems and opportunities in the fight to limit anthropogenic climate change.

With a fossil-fuel heavy global energy system, methane looked like a 20^th century success story in terms of tackling climate change. In the UK, the ‘Dash for Gas’ helped to nudge out carbon-intensive coal-burning power stations for more efficient, lower-emitting gas-fired versions. Per unit of electricity produced, gas power stations were emitting less than half the carbon dioxide of their coal-powered predecessors.

Since those heady days of North Sea exploitation that poured oil, gas and money into the UK, getting enough methane to keep the powerstations, cookers and boilers going has become increasingly difficult. National and global demand for gas has rocketed and easily-exploited supplies have dwindled. Imports of gas from Russia have risen, and with them the volatility of price and supply.

Now, the global expansion of a new extraction technology called ‘fracking’ heralds a new ‘Dash for Gas’ that could serve to provide energy security and carbon emission cuts which dwarf those of the last gas boom.  Unfortunately, this new process, and the vast reserves of gas it makes available, pose a major threat to avoiding dangerous climate change.

Fracking is a process whereby water, chemicals and sand are injected at high pressure into methane-bearing rock and shale deposits. The high pressure water opens up fissures in the rock and the sand particles (called proppants) then keep them open to allow the methane to flow. Once’ fracked’ the methane in the rocks can then be drawn out and used. The process is already used widely in the US, with huge extractions from the methane-rich Marcellus shale in the east of the country underway.

The huge volumes of ‘fracked’ methane have allowed the US to radically reduce its domestic use of coal and to close in on full energy security. So far, so good. However, coal production in the US has continued unabated, with the bargain-price coal now being shipped overseas (much of it to Europe) and burnt for energy generation there. In effect, methane fracking in the US has meant a reduction in US carbon dioxide emissions, but an increase globally. Add to that the great uncertainty over the amount of methane that is leaked from fracking sites and this new ‘Dash for Gas’ begins to look like a major problem for climate change mitigation.

To our atmosphere, exactly where greenhouse gases come from does not matter, it is the amount emitted globally that counts. ‘Dangerous’ climate change is commonly cited as being a post-industrial increase in the global average temperature of 2^oC. We have already seen warming of 0.75^oC and, on our current course, we are likely to well exceed the 2^oC level during this century. Global expansion of methane fracking helps to lock us into this high emissions trajectory. It means a new generation of gas-fired power plants that will go on emitting CO₂ for decades to come, while renewable generation struggles to compete with the low-cost, short-term gas bonanza.

For the jobs and growth agenda of most governments though, methane fracking is inevitably seen as a boon. In the UK it could help buffer energy prices and create new income streams as North Sea wells run dry. Globally it can help power economic development and temporarily bridge gaps between supply and demand.  Methane fracking exemplifies the kind of tradeoffs that have to be made between energy security and climate security, but there is little evidence that such tradeoffs have been properly assessed by the governments backing the fracking boom.

They like gas and so do I, but methane is a fossil fuel. As such our reliance on it has to wane rather than wax in the face of accelerating anthropogenic climate change. It is time that policies on fracking and similarly Janus-faced pillars of ‘sustainable growth’ began to encompass the time-span of human lives instead of parliaments.

Prof. Dave Reay is Chair in Carbon Management & Education at the University of Edinburgh’s School of Geosciences. Dave is Assistant Principal Environment & Society and the Director of the Global Environment and Society Academy, he is the designer and editor of the climate change science website Greenhouse Gas Online and of the Southern Ocean: Antarctic Seas and Wildlife website and has authored a number of books on climate change, including children’s book, ‘ Your Planet Needs You! A Kid’s Guide to Going Green’.  For more information about Dave and his work visit the GESA website