Try to explain global warming and you necessarily come to a point where you must use terms such as carbon dioxide, methane and nitrous oxide. These are the gases that are increasing in the atmosphere due to our human activity. Molecules of three or more atoms capture the incoming energy of the sun in what is known as the greenhouse effect. That is why oxygen is not a greenhouse gas - it has only two atoms in a molecule.
Without the greenhouse effect the Earth would not be warm enough for life as we know it. But increasing the natural greenhouse effect by changing the balance of molecules in the atmosphere is the biggest global issue of our times. Capturing more of the incoming heat from the sun's rays means that the Earth is warming. A few degrees increase on averagemay not seem like much, but it will have disatrous consequences if we do not act promptly. Climates are changing all over the globe, with more extreme weather such as giant hurricanes are now occurring worldwide as predicted. This type of global temperature change has happened many times in the Earth's geological past, but today an increasing effect is racing out of control at a pace much faster than seen before.
To understand global warming, and judge the scientific evidence about it and what can be done to slow the effect, requires people to be able to think about molecules that act as greenhouse gases. Where do they come from? How do they influence temperatures?
To understand how methane captures about 25 times more heat than a carbon dioxide molecule is not hard - once you begin thinking with molecules.
Global warming is a topic that is present in most Primary school classrooms. I enjoyed finding new resources to engage students with the concept of greenhouse gases and their chemistry. There are also opportunities to integrate science and maths through the exploration of relative size on websites such as: www.powersof10.com.
ReplyDeleteTanja Novakovic - Melbourne Uni primary teaching student