How do we Predict the Future of the Environoment?

Climate science, particularly in relation to global warming is a predictive science, so it is important that we know our predictions are accurate. The simplest way to ensure that models are accurate is to test their predictive ability on climate records that we already know. The data is inputted into a computer for a certain date, and then the simulation is run. By the end of the time period, the results of the model and the actual recorded results from around the world are compared. If the results are very similar, then the model is proven to be reliable.

Often, sceptics note the discrepancy between different climate predictions. The IPCC, for example, notes that within one hundred years the temperature of our planet will have increased between 2ºC and 6ºC, depending on which model is used. While sceptics suggest that this indicates doubt, in fact, the opposite is true - all tested and approved models that look forward demonstrate that increased greenhouse gas emissions lead to global warming and that we are experiencing (and will continue to experience to a greater degree) climactic changes that are beyond natural variation.1

What few people know is that "as early as 1975, Syukuro Manabe, who was then working at the U.S. Weather Bureau, and his collaborator Richard Weatherald used computer models to investigate the consequences of a doubling of CO2 in the atmosphere. They found that it would cause a rise in the average surface temperature of the earth by 4.3oF. By 1979, more technologically advanced models had been employed, and these suggested that the rise was more likely to be 6.3 to 7oF, give or take a couple of degrees. Astonishingly, for over twenty years this prediction and its degree of uncertainty hardly changed..."2 In other words, with increased computer power and new modelling techniques, we are consistently finding the same result - that increased carbon dioxide in the atmosphere leads to global warming.

What Does the Future Hold?

We have to be very careful with the notion of scientific prediction. The word "prediction" sounds like something unscientific, like Nostradamus. However, scientific predictions on climate change are, as we have seen, based on models that we know work. There are parameters which help create differing models which lead to differing results, but it is essential to note that all the results point in a very similar direction. We know that the world is heating, and that human carbon emissions have caused it. We don’t know the exact temperature by which the Earth’s atmosphere will rise - 1°C or 5°C - but we do know that it is heating and will continue to heat. So while scientific predictions vary, it is important to note that they all point in the same general direction.

We know now that the tropics are expanding in a way that was not predicted to happen until the next of this century. This is likely to turn dry, subtropical regions even more arid, threatening the lives of the millions of people who live in these areas. The study, published in Nature Geoscience, indicated that the expansion of the width of the tropics "could also bring an increase in the area affected by tropical storms, or could change climatologically tropical cyclone development regions and tracks."3

We know that small, island countries are going to disappear, particularly those countries in the Pacific, and that this will create around 100 000 environmental refugees.4 We don’t know exactly when these countries will be inundated, but we do know that it will happen.

We know that CFCs - chlorofluorocarbons - damaged the ozone layer and that as a result of the Montreal Convention this damage is slowly being repaired. However, it is now known that CFCs brought about Global Dimming, which meant that they helped block out some of the Sun’s radiation. Great volcanic eruptions, which produce very similar emissions, have a measured effect on the Earth’s temperature, which means that we can measure the exact effect of our own similar emissions. As the CFCs leave our atmosphere, the effects of global warming will become more evident.

We know that the Poles will warm more rapidly than the rest of the earth, that rainfall will be increased but more localised, and that there will be more extreme and more intense weather events.5

We know that through any reasonable scenario, by 2050 human influences on the climate will have surpassed all natural influences. That means that there will be no more "acts of God." British snow cover will decrease by up to 80% near the coast, and 60% in the Scottish highlands. Winter rainfall will increase by up to 35%, and the record-breaking summer temperatures of 1999 will become the average minimum temperature.6 "Records kept by the International Disaster Database indicate that the incidence of flood and windstorm disasters has not only increased markedly since the 1960s, but the events themselves are more intensive, last longer and affect more people."7 Indeed, so many were the climate-change related disasters in 2007 that the UN’s emergency relief co-ordinator Sir John Holmes has 2007 was a year of climate-change "mega-disaster."8 The 12 climate-related disasters were floods in lowland and drought in highland Bolivia (February) affecting 300,000 people, a cyclone in Mozambique (March 12th) affecting 285,000 people, six storms and cyclones in three months in Madagascar (March) affecting 500,000 people, torrential rain in Zambia (March) affecting 1.4 million people, storm flooding in Pakistan (July) affecting 2.5 million people, severe drought in Swaziland (July) affecting 500,000 people, intense drought in Lesotho (July) affecting 553,000 people, floods in Sudan (August) affecting 400,000 people, heavy rains and flooding in Uganda (August) affecting 300,000 people, torrential rain in North Korea (August) destroying or damaging 240,000 homes and affecting 1 million people, Hurricane Felix (category 5) in Nicaragua (September 14th) making 100,000 people homeless, severe flooding across Ghana and west Africa (October) making 700,000 people homeless.9

We know that as the seas and the troposphere warm, not only will the frequency and intensity of hurricanes increase, causing overwhelming human misery because of fatalities and the overwhelming number of people made homeless, but also the increase in water vapour will lead to floods which are already wrecking economies across the world. For example, "in the summer of 2002, two fifths of the Republic of Korea’s annual rainfall fell in a week, wreaking such destruction that the nation had to mobilize its troops to help flood victims. At the same time, China suffered floods of historic magnitude, with 100 million people affected."10 In 2007, hundreds of thousands of people were made homeless in floods that stretched across Africa, particularly in Sudan where 250,000 people were made homeless from the capital city, Khartoum, alone.11 The stagnant water from the floods in turn leads to plague, such as cholera, malaria, dengue fever, and encephalitis. It should be noted that in recent years "the world has seen the most powerful El Nino event ever recorded (1997-98), the most devastating hurricane in 200 years (Mitch, 1998), the hottest European summer on record (2003), the first South Atlantic hurricane ever (2002), and one of the worst storm seasons ever experienced in Florida (2004)."12 We now know that these are connected, and that there is worse to come.

We now know that there are "tipping-points" beyond which certain processes become "runaway processes," that is, we cannot stop them. "The palaeoclimate record shouts out to us that, far from being self-stabilizing, the Earth’s climactic system is an ornery beast which overreacts even to small nudges."13 There is already much concern that the North Pole has entered a runaway melting, or a "positive feedback process," by which more sunlight is absorbed into the oceans, which then heat more, causing more sunlight to be absorbed and so on. As more forests are cleared, it is established that we are near another tipping point in which our land "carbon sinks" may start to become "carbon sources," after which time reducing our emissions will only minimise the global warming effect. In 2007, a study in Nature said that the amount of carbon dioxide absorbed by the world’s forests has declined, and that they may be shifting towards becoming carbon sources.14 Another "tipping point" of real concern is the amount of greenhouse gases locked in the permafrost, which is now beginning to melt. Should it do so, the quantities of greenhouse gases that will be released will be catastrophic. There is also concern that with the oceans being heated, more water vapour, itself a greenhouse gas, will be released, further increasing the temperature.15

We know that droughts and heat-waves are set to increase in frequency and intensity. In 2003, Europe experienced its most devastating heat-wave on record, the final death-count being around 50 000 people. The average temperature in some countries is set to rise significantly higher than the global average - "by 2030 most of Australia is expected to experience between 10 and 50 percent more days over 35ºC."16

We know that malaria, which already infects half a billion people each year (or, put another way, one in twelve people on the planet) is set to continue to rise. Already three million people die each year of Malaria - one million children below the age of five in Africa die each year from Malaria - that is, one every 30 seconds.17 "Indeed, when World Health Organisation (WHO) scientists estimated that 160,000 people already die each year from the indirect effects of climate change, malaria was one of the main factors they pointed to."18 Part of the reason that we know malaria will increase is not only because of the increased stagnant water ponds, but because the North American mosquito is already showing signs of adapting to climate change, entering it’s winter dormancy later than it used to, and thereby increasing the time it has to infect human beings.19

We know that species are moving poleward by around 4 miles per decade, up mountains by about 20 foot per decade, and that spring is advancing around 2.3 days per decade. (Incidentally, these trends accord so strongly with the scale and direction of temperature increases brought about by greenhouse gas emissions that Parmesan and Yohe’s findings have been hailed as constituting a globally coherent "fingerprint of climate change.")20 We now that with these migrations, human changes to the environment will cause large-scale extinctions.

We know that biased sex ratios are being formed in reptiles and amphibians because of the increased global heat, and that this is likely to be the cause of the extinction or near-extinction of a number of such creatures.21

We know that around 20 million people are likely to have their lives affected by flooding by the year 205022 because so many people live so close to the coast. For example, "in Bangladesh alone, more than 10 million people live within three feet of sea level."23

We know that the last time the Earth’s greenhouse gases were at 500 ppm (around 20-40 million years ago), the seas were 300ft or 90m higher than they are today. This does not necessarily mean that the same sea rise is inevitable at that figure today24 (partly because of the aforementioned Global Dimming), but we do know it is possible.

We know that the rate of climate change currently being experienced and predicted to be experienced in the future is too fast for many species to adapt. It is not just the changes in temperature which will affect the extinction of species, but the speed of those changes, to which many animals will not be able to adapt quickly enough.25

We know that the collapse of some civilisations is now possible,26 and the collapse of some towns or cities is now likely. Cities cannot relocate and if life becomes untenable in those locations, they might need to be emptied, creating many more thousands of environmental refugees on top of those whom we already know will be created. We cannot be sure which cities will become untenable, although many are looking at cities in the American west which are intimately connected to water supplies that are decreasing.27 It is widely known that governments are working on strategies to adapt to these changes and the corresponding behaviour among the population and between countries. Our way of life has been designed around a "long summer"28 that has lasted around 8000 years, and around which our civilisation is based. By changing the temperature outside the norms of those last 8000 years, we know that some elements of our civilisation will have to give way. Since we have based our way of life, and in particular, our cities, around the ability to bring in enough food, water and power, as well as to support other institutions such as arts, as soon as the ready availability of food, water or power comes into question, the local civilisation becomes threatened. It is known that societies in the past have failed because of a lack of resources, either on Easter Island or the Mayan people.29 Because cities are based around localised networks of availability of food, water and power, when these are no longer available, the city has to be abandoned. This is not to say that civilisation as a whole will collapse, although there are some authors who hold this is very likely. What we can say with a good degree of certainty, though, is that we know that some cities are very likely to collapse.

We know that many of the plans of governments to adapt to climate change involve the assumed death of millions of people worldwide, to the point that they were described by Aubrey Meyer, creator of Contraction & Convergence, as having taken on "a genocidal meaning," in which the wealthy few survive while the poor unpolluting nations suffer from the emissions of the wealthy few. According to Meyer, this is essentially "the effective murder of members of the world’s poorest populations."30

We know that the rate of greenhouse gas emissions is increasing, not decreasing, and that the only way to reduce emissions is by making drastic and rapid cuts.31

We know, most disturbingly, that we cannot fully predict what is going to happen. This is an experiment that has never before been witnessed. "It’s clear that the greenhouse-gas content of our atmosphere has entered territory never before explored in human history. Only time will tell how quickly the climate might follow."32 In 1957, Roger Revelle and Hans Seuss explained the concerning state of affairs thus: "human beings are now carrying out a large scale geophysical experiment of a kind that could not have happened in the past not be reproduced in the future. Within a few centuries we are returning to the atmosphere and oceans the concentrated organic carbon stored in sedimentary rocks over hundreds of millions of years."33

1. Dow and Downing (2007), p. 29, 36
2. Flannery (2005), p. 154
3. The Independent newspaper, Dec 3rd 2007, p. 2
4. Ahmed Djoghlaf, Plaet Earth (2006), p. 126
5. Flannery (2005), p. 159-160
6. Flannery (2005), p. 164-5
7. Dow and Downing (2007), p. 26
8. The Guardian newspaper, Oct 5th 2007, p. 20
9. The Guardian newspaper, Oct 5th 2007, p. 20
10. Flannery (2005), p. 138
11. The Independent newspaper, Sep 18th 2007, p. 25
12. Flannery (2005), p. 136
13. Wallace Broecker, q. Flannery (2005), p.45
14. The Independent newspaper, Nov 1st 2007, p. 20
15. Henson (2006), p. 198
16. Dow and Downing (2007), p. 26
17. The Ecologist, Vol 38, Issue 3, April 2008, p. 49
18. Henson (2006), p. 147
19. Dow and Downing (2007), p. 20
20. Flannery (2005), p. 88
21. Flannery (2005), p. 90-1
22. Henson (2006), p. 131
23. Flannery (2005), p. 143
24. Robert May, Planet Earth (2006), p. 132
25. Flannery (2005), p. 59
26. Dow and Downing (2007), p. 53
27. Flannery (2005), p. 134
28. Flannery (2005), p. 63
29. Flannery (2005), p. 203-5
30. Flannery (2005), p. 207-8
31. Flannery (2005), p. 319
32. Henson (2006), p. 216
33. Henson (2006), p. 217