1.2: Converting to geometric form You have seen how any vector given in geometric form, in
terms of magnitude and direction, can be written in component form.
You will now see how conversion in the opposite sense may be
achieved, starting from component form. In other words, given a
vector
a = a
1
i + a
2
j,
what are its magnitude |a| and direction θ? The first part of this question is dealt with using
Pythagoras’ Theorem: the magnitude of a v
Acknowledgements All materials included in this unit are derived from content originated at the Open University.
2.2 Vibrant civil societies and a networked globe One thing is common to all three attempts to find a route to a sustainable economy and society: in different ways they all assume that people will get actively involved in making human societies more sustainable. But this transformation will not take place through the corporate world's promises, by local protectionism, a return to ‘strong states’ or the publication of numerous indicators. Any of the three positions outlined above requires interactions and feedbacks created by a vibrant
Learning outcomes By the end of this unit you will: Have gained an understanding of the four dimensions of globalisation in relation to climate change; Be able to distinguish between the three approaches to achieve sustainability; Know the difference between ‘government’ and ‘governance’; Identify what makes ecological citizenship distinctive; Understand how the medium of the web can aid transitions to sustainability.
Introduction Human societies have to take urgent action to end their dependence on fossil fuels. They also have to prepare to adapt to the uncertainties inherent in global environmental changes, particularly climatic ones. 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 this might come about. The context for these changes by g
Acknowledgements The material acknowledged below is Proprietary and used under licence, see terms and conditions). This content is made available under a Creative Commons Attribution-NonCommercial-ShareAlike 2.0 Licence Grateful acknowledgement is made to the following: Figur
Figures
5 The contemporary Arctic climate There is a remarkable seasonality in the Arctic climate. For example, the flow in some of the great rivers of Russia and North America that empty into the Arctic Ocean almost stops in winter (Figure 21). During May, ice in the rivers starts to break and in June there is a rapid flood of fresh water followed by a
3.1 Greenland's snowfall Greenland snowfall differs depending on whether it falls in summer (when snow is comparatively warm and moist) or winter (when snow is cold and dry). These differences mean that as the snow is turned to ice, annual layers are formed that are in many ways similar to tree rings: thick annual layers mean high snowfall and thin annual layers low snowfall. The accumulation of snowfall on the summit of Greenland – and most importantly what is trapped within the crystals as it turns to ice – can
1 A climate change icon The polar bear has become an international climate change icon. But how much is known about this bear, its habitat and life? This unit will talk about the role of language, but by way of introduction how about the name of this bear? To me it is the polar bear; to a German it is an Eisbär (ice bear) and to a French person it is an ours blanc (white bear). In these three examples the bear is referred to as polar, white, or an ice bear – eminently sensible. The Latin name for th
Learning outcomes By the end of this unit you should be able to: appreciate how chemical processes in the rest of the world affect the Arctic environment and the species inhabiting it; recognise the physical processes that determine atmosphere and oceanic flows in the Arctic; appreciate the scientific research process and the use of scientific evidence; use quantitative scientific evidence to examine the link between atmospheric carbon dioxide levels a
Introduction The scientific theory of plate tectonics suggests that at least some of these Arctic lands were once tropical. Since then the continents have moved and ice has changed the landscape. This unit will concentrate on evidence from the last 800,000 years using information collected from ice cores from Greenland and Antarctica, and will use this evidence to discuss current and possible future climate. The cores show that there have been nine periods in the recent past when large areas of the Earth
6.1 ‘I’, ‘we’ or ‘they’? We must abandon the conceit that individual, isolated, private actions are the answer. They can and do help. But they will not take us far enough without collective action. (Al Gore, 2007) There are some things that we can do as individuals: making this an energy-efficient house and making smart transport choices. Then there a 5.3 Moving towards a sustainable carbon footprint So far, you've been considering reductions in average individual or household carbon footprints by 20% to 30% or more. But it is becoming increasingly clear that this will not be enough. As I mentioned in Section 4, developed countries, like Britain, Germany and America, will have to reduce their CO2e emissions by 60% to 80% or more by 2050 to prevent climate change running out of control, while at the same time allowing the growing populations of Africa, India and China to r 5.2 Lighter living costs and constraints The costs of ‘light living’ actions need, of course, also to be considered. Some actions involve no cost or save money, for example, less flying, shopping or meat eating, or can even make money, such as letting out a spare room to increase household occupancy. Others are low cost with a rapid payback time; for example, replacing an incandescent light bulb with a low-energy compact fluorescent lamp (CFL) should pay back the new lamp's cost in lower electricity bills in about 5.1 Actions for lighter living Nobody made a greater mistake than he who did nothing because he could only do little. (Edmund Burke, 1729–1797) If you want to consider how to further lighten your carbon footprint, you may need more detailed information on the effect of technical and behavioural actions not covered by the carbon calculator, or included only as a part of other actions. It's important to understand whic 1.1.2 The carbon footprint boundary Depending on where you draw the boundary, the carbon footprint can apply to an individual person, a household, an organisation or event, a product, a city, region or country, or the whole world. I'll mainly be considering the footprints of individuals, households and the countries they occupy. But even then the boundary needs to be defined carefully. Sometimes the carbon footprint is taken to mean the individual's or household's direct CO2 emissions, main 2.2 Records of the Earth's temperature To put the temperature records reported by the IPCC in context, we start with a longer-term geological perspective on the Earth's GMST. 1.5 ‘Radiative forcing’ as an agent of climate change Since its first major report in 1990, the IPCC has used the concept of ‘radiative forcing’ as a simple measure of the importance of a potential climate change mechanism. The basic idea is straightforward. Any factor that disturbs the radiation balance at the top of the atmosphere has the potential to ‘force’ the global climate to change: it will either warm up or cool down until a balance is restored. The perturbation to the energy balance of the whole Earth-atmosphere system i 4.1 What are renewable energy sources? Fossil and nuclear fuels are often termed non-renewable energy sources. This is because, although the quantities in which they are available may be extremely large, they are nevertheless finite and so will in principle ‘run out’ at some time in the future. By contrast, hydropower and bioenergy (from biofuels grown sustainably) are two examples of renewable energy sources – that is, sources that are continuously replenished by natural processes. Renewable energy sourc 2.2.3 Ecological economics Ecological economics, which formally came to prominence in the mid-1980s, represents a departure from reliance on the use of mainstream economic modelling. Instead, it branches out to actively engage with and incorporate the ethical, social and behavioural dimensions of environmental issues. In short, ecological economics attempts to provide an interdisciplinary approach to environmental issues, whereas environmental economics maintains the primacy of economic modelling. Mark Sag
