1.3 Energy flows within the Earth-atmosphere system Before we focus on the enhanced greenhouse effect, we need to refine the schematic representation in Figure 7 and draw in some of the other processes that influence the Earth's temperature – not only at the surface, but also at different levels within the atmosphere.
1.2.2 Bringing in the atmosphere: the natural greenhouse effect As a dam built across a river causes a local deepening of the stream, so our atmosphere, thrown as a barrier across the terrestrial rays, produces a local heightening of the temperature at the Earth's surface. (Tyndall, 1862, quoted in Weart, 2004) Thus, writing in 1862, John Tyndall (Figure 6) described the key to our modern understanding of why the Earth's surface is so much warmer than t
1.2.1 Heating and cooling the Earth: the overall radiation balance The Sun emits electromagnetic radiation with a range of wavelengths, but its peak emission is in the visible band – the sunlight that allows us to see. The wavelength of radiation has important climatic implications, as we shall see shortly. For now, we are mainly interested in the overall rate at which energy in the form of solar radiation reaches the Earth. 1.1 Introduction At the beginning of the 21st century, terms such as the ‘greenhouse effect’, ‘greenhouse gases’ and ‘greenhouse warming’ are printed or spoken thousands of times a week in the context of climate change caused by human activities. This section is designed to consolidate your understanding of the basic science behind these terms, and then to review what is known about the human impact on the composition of the atmosphere since the dawn of the industrial age, commonly put (in this co Learning outcomes Having studied this unit you should: understand the physical basis of the natural greenhouse effect, including the meaning of the term radiative forcing; know something of the way various human activities are increasing emmissions of the natural greenhouse gases, and are also contributing to sulphate aerosols in the troposphere; be aware of the difficulties involved in the detection of any unusual global warming ‘signal’ above the ‘background Introduction This unit explores the topic of climate change and global warming. We will begin by exploring how the Earth’s global mean surface temperature is determined through a global “balancing act” of the rate of energy that comes from the Sun and the rate at which the planet returns that energy into space. We will also discuss the natural greenhouse effect, and how this contributes to a balanced global climate. We will then go on to consider the human impact on the atmosphere, including the imp Acknowledgements Grateful acknowledgement is made to the following sources for permission to reproduce material in this unit: The content acknowledged below is Proprietary and used under licence (not subject to Creative Commons licence). See Terms and Conditions. Box 1: ‘O sweet spontaneous’. Copyright 1923. Trustees for the E E Cummings Trust. Box 5: Maugh, T H (2008) ‘The MIT Meteorologist’s theory References 2.3 Citizens in conversation with nature and experts Before leaving office in 2008, Sir David King (the ex-Chief Scientific Advisor to the UK Government) introduced an ethical code for scientists. This drew particularly on his experience in working across the scientific–political divide on issues of climate change. The code comprises three attributes of scientific endeavour: rigour, representation and responsibility (Author(s): 1.4.2 Engaging with multiple perspectives A systems approach begins when first you see the world through the eyes of another. (Churchman, 1968, p. 231) The Ulrich reading is an extract from an article written in honour of another systems philosopher, C. West Churchman. Also drawing on Churchman's influence, Jake Chapman sums up two qualities of systems thinking in terms of ‘gaining a bigger picture (going up a level of abstraction) a 1.4.1 Dealing meaningfully with holism Ulrich's primary observation is quite straightforward. Any system as a human construct is unable to capture the total complexity of interrelationships and interdependencies that make up the real world. This idea resonates with the paradox of framing referred to by Moore. It also resonates with Ilan Kapoor's reference to the work of Slavoj Žižek, quoted earlier: ‘Reality is what we (mistakenly) take to be wholeness or harmony, while the Real denotes the impossibility of wholeness’ (Kapoo 1.4 Nature matters in terms of a critical systems literacy The systems philosopher and social planner Werner Ulrich has long argued for a more ethically informed idea of systems. Before looking at Ulrich's ideas, however, it is worth returning to examine the relevance of the earlier Moore and Martell readings to this subject. One of the hallmarks of systems thinking is a recognition of the limits of holism, relating to the problem of aesthetic framing expressed by Ronald Moore (2006, p. 263): 1.3 Framing nature matters as systems Much of what is considered Nature is often codified as ‘systems’ – natural systems, ecosystems, ecological systems and/or environmental systems. Systems thinking is an active cognitive endeavour to conceptually frame reality. A key feature of framing Nature in terms of systems is the appreciation given to the multiple interrelationships and interdependencies that exist in the natural world. The Thing – that is, the repercussions of the eighteenth-century European industri 1.2 A framing paradox: experiencing nature with cognitive tools Whilst language tools are helpful in conveying meaning in conversation amongst humans, establishing what matters in ‘conversation’ between human and non-human nature, or amongst non-human living entities, requires different cognitive tools. Cognition refers to the way in which external information from the environment is processed. As sentient beings, humans and some other animals are able to experience wellbeing and suffering. In the next reading, Ronald Moore examines how we engage with 1.3.5 Corporate connections As I mentioned in Section 2, what was happening in the factories of overseas contractors was said to have appeared remote to most, if not all, the chief executive officers of the clothing multinationals in the 1980s. Overseas contractors were selected on the basis of market price, quality and reliability, not on whether forced or child labour happened to be employed to stitch the product together. However, all that changed in the early 1990s when the geographical ties between the big retailer 1.2.5 Offshore fragments of industry: a pro-market standpoint From a pro-market standpoint, global market forces and the competitive pressures that they generate leave businesses with no choice but to take advantage of lower labour costs elsewhere. In the textile business or the toy business, lower wage costs are the key to profitability; if your competitors find a cheaper labour source, you either follow their example or go out of business. It is not, so the argument runs, because managers lack integrity or compassion that there are now more manufactur 1.2.3 Activity 2 Before you read on, I would like you to dwell for just a moment on the significance of this shift from direct investment by Western firms to the establishment of subcontracting ties with overseas partners. Aside from outside firms being able to p 1.2.2 Offshore fragments of industry The rise of global factories in the 1970s owed much to the rapid improvement in transport and communications technologies which took place at that time and which made it possible to keep in touch with, and control, production processes in different parts of the world. Just as significant was the fragmentation of industrial production whereby parts of the manufacturing process could be relocated over vast distances. Sewing in garment and footwear production, for instance, was among the 1.1.2 Activity 1 You have already glanced at Figure 1 and some of the worki Acknowledgements The content acknowledged below is Proprietary (see terms and conditions) and is used under licence. Grateful acknowledgement is made to the following sources for permission to reproduce material within this unit. Box 4: Four Scenarios for 2050, Royal Commission on Environmental Pollution, 22nd
Report, Energy– The Changing Climate, June 2000. Crown copyright material is reproduced under class licence number C01W0000065 with the p
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