There have been many attempts to measure the ‘state of the world's environment’ and to show the scale of human impacts.17 The changes are complex, and statistics on global change suffer from problems of quality and completeness. There is no lack of conservative sceptics claiming that environmentalists exaggerate.18 In response there have been efforts to define ‘headline’ statistics, such as the World Wide Fund for Nature's ‘Living Planet Index’ (LPI), first calculated in 1998.19
The remarkable extent of human impacts on the biosphere (in terms of the expansion of industrial capacity, and the urbanisation and socio-cultural changes that accompany it) is beyond doubt. Indeed, the unprecedented scale of human modification of geological and ecological processes is so great that it is now proposed that they be marked by a new geological epoch, the Anthropocene.20
The capacity of human society to influence biological and geological processes has accelerated rapidly over the twentieth century (Table 3.1). These changes were particularly sharp in the ‘great acceleration’ in industrialisation and energy use that followed the Second World War (Figure 3.1).21 Graphs of global population, urban population, and consumption (for example of fertiliser, paper or fresh water, the level of international telecommunications, the number of motor vehicles or the magnitude of international tourism) all show steep rises in the second half of the twentieth century. In the last five decades, humans have begun to change the earth at a rate and on a scale and through a combination of human activities that was fundamentally different from anything that had gone before in human history. Science has barely been able to keep up with our influence: as Peter Vitousek and colleagues observed in 1997, ‘we are changing the earth more rapidly than we are understanding it’.22
Figure 3.1 The change in human enterprise from 1750 to 2000
The ‘great acceleration’ is clear: every component was either not present before 1950 or accelerated sharply after 1950
Source: Steffen et al. (see note 20)
Table 3.1 Human impacts on the biosphere
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At the start of the twenty-first century, there is no doubt that we are ‘in the midst of one of the great extinction spasms of geological history’.36 Global consumption munches through species and habitats like Pac-Man,37 consuming, displacing and converting them to human use, exchanging living diversity for industrial monocultures, species-poor built environments and degraded barren lands and seas.
However, the most significant features of the Anthropocene may yet prove to be biogeochemical, and their impacts directly material to the quality of human lives across the globe: a 16-fold growth in energy use in the twentieth century including a sixfold increase in coal extraction; association sulphur dioxide emissions twice natural emissions; nitric oxide, carbon dioxide, and methane emissions all far above background levels; the release of manufactured chemicals such as chlorofluorocarbons.38 The Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report (2007) found that the globe is likely to see a rise in temperature by about 3°C over the next century. Eleven of the twelve years 1996–2006 were among the twelve warmest years in the instrumental record, which began in 1850.39
‘global consumption munches through species and habitats like Pac-Man’
These human signals in the wider geological and biological systems of the planet earth are not simply of scientific interest. They have a much more obvious practical and material importance in terms of human futures. The Stern Review on The Economics of Climate Change in 2006 provided a detailed warning that, if unabated, climate change could cause environmental costs equivalent to 5–20% of global GDP.40 The kinds of climatic tipping points being discussed by scientists (Table 3.2) are replete with hazards for humankind.
Table 3.2 Tipping elements in the earth's climate system
| Tipping element | Global warming parameter | Key impacts |
| Disappearance of Arctic summer sea ice | 0.5–2°C | Amplified warming, ecosystem change |
| Greenland ice-sheet meltdown | 1–2°C | 2–7m rise in sea level |
| West Antarctic ice-sheet collapse | 3–5°C | 5m sea-level rise |
| Reorganization of the Atlantic thermohaline circulation impacts on inter-tropical convergence | 3–5°C | Regional cooling, sea-level effects, |
| El Niño Southern Oscillation (ENSO): increased amplitude elsewhere | 3–6°C | Drought in South-east Asia and |
| Indian summer monsoon: change in variability | Temperature not concerned | Drought |
| Sahara/Sahel and West African monsoon: collapse | 3–5°C | Increased rainfall in the Sahel |
| Amazon rainforest: dieback | 3–4°C | Biodiversity loss, decreased rainfall |
| Boreal forest: dieback | 3–5°C | Biome switch |
Source: Lenton et al. (see note 13).
There are no road maps for the future that faces humankind in the twenty-first century. People have not been here before. The things that got us here are not necessarily well adapted to solving the problems that now face us. Our ideas, forms of political engagement, laws and established ways of working are the very things that created our current situation. We face a future to which the past is at best a poor guide.
Of course, changes in human economy and society offer opportunity as well as threat. The nineteenth and twentieth centuries brought numerous technologies with astonishing potential to improve the human condition. Rising energy use reflects and contributes to improved human living conditions. Thus a simple technology such as electric light can transform people's lives, not least by allowing them to read after dark. And the increasingly ubiquitous mobile phone is transforming market and social interactions in developing countries. Access to the internet offers amazing opportunities for improved lives through greater connectedness.
‘there are no road maps for the future’
The very concept of a global environmental movement was made possible by technologies like the space flight that allowed astronauts to look back on the spinning earth and give environmentalism its imagery, or the satellites whose sensors allowed the monitoring of tropical forest loss. And, arguably, the environmental movement itself depends for its success on continued technological innovation such as global citizen-to-citizen communication, and innovations such as Web 2.0.41
However, mobile phones and the internet, like so many other advances, depend on heavy investments in manufactured products that rapidly reach obsolescence and are not reused or recycled.
In the UK alone, 1700 mobile phones are thrown away every hour, 15 million every year: their heavy metals and other pollutants (mercury, lead cadmium, brominated flame retardants) almost all still left un-recycled.42 The internet makes massive energy demands through server farms to provide the computing power to run search engines, and the billions of computers that comprise the internet itself. Almost all new technological innovations brought to market depend on cheap energy and assumptions about the capacity of the biosphere to absorb wastes.
Technologies and new forms of social interaction can contribute to a transition to sustainability, but they are also products of what needs to be transformed. However great their potential, they are an inescapable part of the human transformations of the Anthropocene, not an alternative to it.
Whatever the potential of new technologies, the scale and above all the velocity of contemporary change are profound challenges. We are being presented with unprecedented rates of change in almost every metric we can devise. Technology and human ingenuity are not currently focused on human survival. How is life (human and non-human) to be sustained?
What metaphor describes modern humanity's attitude to the biosphere? Perhaps not astronauts gazing awe-struck at the earth, but the drivers of mundane SUVs, stuck in traffic on a high road to nowhere:
‘nobody seems to be in charge’
Video clip 1:
The screen fills with an aerial panorama of a vast dark dystopian cityscape. The camera zooms down and down, past beetling skyscrapers through layers of smog to a huge freeway thick with moving traffic. Panning forwards, it appears that the road leads straight off a cliff. The camera zooms closer, moving through the lines of moving cars, which are all full of people: men, women and children. Inside them all, arguments are raging. Nobody seems to be in charge. Different people grab for steering wheels, but the cars do not turn. It is clear that the people in the cars are not controlling them. Someone must have programmed the cars and set the route, but it seems nobody quite knows who. Lots of people are arguing about the route, the cars' speed and internal management. One car contains famous world leaders. They are worried about whether the car's engine is firing properly, and whether they have packed enough clothes for their next meeting. One is full of environmentalists who work in the sustainability industry; they know that the cliff is there, and they are setting up discussion groups to debate a downshift in the cruise speed and the cost effectiveness of catalytic converters. One is full of academics, trying to design a more accurate speedometer, and modelling the implications of a fuel shift to biodiesel. In another car, business executives are thinking how to increase their share of the space inside their car, and how to take over the ones next door. Every car is full, but there are also people crammed together on their roofs and hanging off the fenders. Many wear rags, and are banging on the windows and asking to get off. Nobody is listening. The cars move on. The cliff edge looms.