2.1 Introduction

In all the analysis of stellar properties discussed so far we have made an implicit assumption - that light emitted by a star is not changed between its emission and its arrival outside the Earth's atmosphere, except by the inverse square law (i.e. it is reduced by a factor of d2, where d is the distance to the star) and by the Doppler effect. However, this may not be the case.

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Bibliography

Ahmed, A. (1987) Better Mathematics, London, HMSO.

DfEE (2001) Key Stage 3 National Strategy: Framework for Teaching Mathematics: Years 7, 8 and 9, London, DfEE.

NCTM (1989) Curriculum and Evaluation Standards for School Mathematics Reston VA, National Council of Teachers of Mathematics.


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Conclusion

In this course you have been introduced to the difference between mathematical content and processes. You have worked on the do–talk–record (DTR) framework for learning mathematics.


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1.2.2 Content

School mathematics curricula often focus on lists of content objectives in areas like number, arithmetic, statistics, measurement, geometry, trigonometry, and algebra. A typical list of content objectives might contain over one hundred objectives to be introduced or revisited and learned each year. These can be seen as hierarchical in nature but many textbooks do not attempt to organise the objectives in ways that enable the bigger underpinning ideas to become apparent to the pupils. In addit
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1.6.2 Alerts

Online bookshops and some of the major search engines offer ‘Alerts’ services. These work by allowing you to set up a profile once you have registered on their site, and when there are items meeting your criteria you receive an email. The good thing about alerts is that you don’t have to do anything once you have set up your profile. The downside, particularly with alerts services from the search engines, is that given the extent to which internet traffic is on the increase whether new
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Climate change
Human societies have to take urgent action to end their dependences on fossil fuels. We have to alter the whole path of our development and decision making in order to make our societies both environmentally adaptable and sustainable. This unit takes on the task of trying to chart some of the ways in which it might be possible. First published o
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Except for third party materials and otherwise stated (see http://www.open.ac.uk/conditions terms and conditions), this content is made available under a http://creativecommons.org/licenses/by-nc-sa/2

4.2.3 Business needs sustainability

The second argument is more profound: long-term profitability, and the existence of business itself, is threatened if companies can't transform themselves. This assumes that although the costs of environmental and social impacts can be ignored for a period, in the context of globalisation of environmental, social and political processes, they will come back to haunt businesses, and ultimately threaten their survival. There are several communications and management tools that have been develop
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2.3.3 Differences between people and places

I said at the beginning of this section that the average individual and household carbon footprints for a country conceal the differences within that country. These differences in carbon footprints are related to income and can be enormous, but difficult to quantify.

For example, in India the 2004 average carbon footprint of 1.2 tonnes CO2 per person per year hides the differences between: middle-class Indian households living in air-conditioned apartments and owning a televi
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1.3.3 The role of clouds

We have already identified one role that clouds play in the Earth's climate: they are highly reflective (Section 1.2.1). At any given time, about half of our planet is covered by clouds; the sunlight they reflect back to space accounts for about 55% of the total planetary albedo. However, clouds also absorb and re-emit outgoing longwave radiatio
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1.3.2 The fate of incoming solar radiation

SAQ 9

Look back at Figure 7. In this schematic representation, what is the fate of incoming solar radiation?

Answer

It is either reflected back to spa
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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.


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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.

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2.2 Environmental pragmatism: positioning expert support

I believe that the principal task for an environmental pragmatism is not to reengage the … debates in environmental ethics but rather to impress upon environmental philosophers the need to take up the largely empirical question of what morally motivates humans to change their attitudes, behaviours, and policy preferences toward those more supportive of long-term environmental sustainability.

(Light, 2002, p. 446)


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References

Anon (2002) 'The Windicator', Windpower Monthly, January, p. 50.
Blake, William (1994) The Marriage of Heaven and Hell, Dover Publications.
Boyle, G. (1966, 2003) Renewable Energy, Oxford, Oxford University Press in association with the Open University.
BP (2002) BP Statistical Review of World Energy [online
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2.2.1 Environmental economics

Environmental economics emerged as a sub-discipline in the 1960s, following a tradition that began in the early twentieth century with ‘agricultural’ economics and continued in the 1950s with ‘resource’ economics. In each case, natural resources are treated as environmental assets in the same way as other resource inputs, using the classical mainstream supply and demand economic models. David Pearce, who at one stage was at the forefront of environmental economics and was an ac
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7.4 Closing thoughts

Of course, doing anything about this needs scientific evidence and understanding, but it also requires social, economic and technological changes, which can only be achieved through political will. If you want to explore some of the broader context, a good place to start would be the New Internationalist issue 357, ‘The Big Switch: Climate Change Solutions’ at New Internationalist.

Faced with the sort of predictions climatologists are making, is it sufficient for science teac
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7.3 Running the models forward

What happens when the models are run forward? It depends upon the models used and the scenarios they are asked to run. It seems almost certain, however, that there will be increases in the global mean surface temperature, to the order of +1.5 to +4.5 °C (– possibly more, according to some models and scenarios.

These changes are predicted to be associated with increases in sea level, changes to weather conditions (e.g. more regular and violent winter storms in the UK) and changes to t
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2 Altering the environment

Later in this unit we will be considering a number of ways in which humans alter their environment.

Question 3

In what ways do you think we are altering the environment?

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1 Why sustainable energy matters

One of the greatest challenges facing humanity during the twenty-first century must surely be that of giving everyone on the planet access to safe, clean and sustainable energy supplies.

Throughout history, the use of energy has been central to the functioning and development of human societies. But during the nineteenth and twentieth centuries, humanity learned how to harness the highly-concentrated forms of energy contained within fossil fuels. These provided the power that drove the
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4.1 Distributive and commutative justice

Justice is commonly thought to have two applications which Aristotle distinguished as ‘distributive’ and ‘commutative’ justice. The first, distributive justice, is concerned with the distributions of things (rights, goods, services and so on) among a class of individuals.