Global warming
Global warming

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Global warming

5 Human influence?

Evidence suggests that global temperature is beginning to rise. There are several factors that could cause this. Only one is affected by human activity.

Click on the link below to view a chart showing the rates of energy gain and loss by the Earth's surface and atmosphere

Energy gain and loss [Tip: hold Ctrl and click a link to open it in a new tab. (Hide tip)]

Up to this point we have been primarily concerned with evidence and trends, with ‘what has happened’. This sort of analysis does not tell you ‘why’ something happened. To understand ‘why’, we need some sort of explanatory model that works on a global scale. The starting point of ‘why’ for climate change, is to consider energy flows in the climatic system. Click on the link above to see a chart showing the rates of energy gain and loss by the Earth's surface and atmosphere.

Note that even though the arrows starting and stopping in the atmosphere do so in small region in the centre, the atmospheric energy gains and losses that they represent take place throughout the atmosphere. 100 units represent the rate at which solar radiation is intercepted by the Earth. The width of each arrow is proportional to the rate of energy transfer.

If you would like a full explanation of the energy flows in the diagram, click on the link below to read more.

What determines the GMST

Activity 3 explores the possible causes that may be disturbing the equilibrium of such a model, and the evidence of human influence.


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