3.1 Who will make the decisions?
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.
2.2 Vibrant civil societies and a networked globe
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.
2.1 Political responses to climate change and the environment
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.
1.2 Globalisation is about networks
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.
1.1 What is 'globalisation'?
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.
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Summary In this part I have presented evidence showing that even apparently remote regions of our planet are intimately connected through physical processes. For example, once an organic POP is transported to the poles, then biological processes can take over and through bioaccumulation perhaps cause harm. But this physical connection has allowed the ice to preserve unique proxy records of the past climate of our planet. Directly measuring the gases trapped in the ice has enabled histories of past at
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 fall in flow until November, when it freezes. 4 The end of the last ice age: the Holocene I have already noted that the great ice sheets took about 100,000 years to form and only about 10,000 years to decay. So what happened at the end of the last ice age? Figure 15 shows the EPICA ice core CO2 concentration and air temperature for the most recent 20 000 years, which is within the last ice age. The temperature scale shows the difference from the average temperature of the last 1000 years, so 0 °C is no 3.3 The Keeling curve The Keeling curve is the plot showing the trend in rising atmospheric CO2 concentrations since 1958 recorded at Mauna Loa in Hawaii. The story of atmospheric CO2 in the last 50 years is a relentless rise derived from human use of hydrocarbons and, as I write this in 2008, the annual mean concentration is 383 parts per million (ppm). When Keeling first collected his CO2 data he travelled around making the measurements at widely spaced locations – but he saw t 3.2 The past temperature of the planet Measuring the concentration of lead in the ice is called a direct measurement: the ice sample is melted and the water produced contains a very small but readily measured quantity of lead dust. A very accurate set of scales would be needed to measure it, but it is a directly measured quantity. There are also many indirect measurements that can be made using proxy data. The concept for using proxies is both simple and brilliant: one measured property allows inference about other states o 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 2 The atmospheric and ocean flows We now know that PBDEs end up in the Arctic through their physical transport by the winds, the ocean and the rivers of the world. All three mechanisms are important, but the most rapid carrier is the wind. The basic principle of global atmospheric circulation is simple: warm air rises and cold air sinks. The warming effect of the Sun is much greater at the equator than at higher latitudes and so the air is much warmer and it rises. At high latitudes the air cools and it sinks. This drives a h 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 fo Next steps 2.8 End of unit question 2.7 Summary 2.6.2 The role of modelling studies 2.6.1 Weighing up the evidence: the full cast of suspects 2.6 An evolving consensus on attribution
Climate change is a key issue on today’s social and political agenda. This unit explores the basic science that underpins climate change and global warming.
Climate change is a key issue on today’s social and political agenda. This unit explores the basic science that underpins climate change and global warming.
Climate change is a key issue on today’s social and political agenda. This unit explores the basic science that underpins climate change and global warming.
Climate change is a key issue on today’s social and political agenda. This unit explores the basic science that underpins climate change and global warming.
Climate change is a key issue on today’s social and political agenda. This unit explores the basic science that underpins climate change and global warming.
Climate change is a key issue on today’s social and political agenda. This unit explores the basic science that underpins climate change and global warming.
