Scottish Sceptic

Over the years I have seen many people arguing about how the Greenhouse effect works and from these discussions it is clear that most people misunderstand it. That is not to say that adding a greenhouse gas like CO2 to a typical atmosphere like the earth’s should not cause warming. Instead, whilst this “greenhouse” warming is a nice & simple way to explain to an average person on street how increasing CO2 would cause warming it is not true any other sense than it is what tends to happen and is certainly not a “law” of nature.
Yes it works to indicate what is happening, unfortunately as soon as people start talking about the detailed mechanisms behind it or worse using it to predict behaviour, this simple explanation fails and cause a lot of senseless argument because it does not and cannot encompass the true complexity of the situation.
So, this guide is intended to go one step beyond the simple “man on the street” explanation.

Greenhouse gases are not really “greenhouses”

It’s indicative that this “greenhouse gas theory” is not the best science when I have to start by saying that the mechanism by which greenhouse warm plants is not at all the same physical mechanism as we are discussing here. The reality is that whilst the sun both warms a greenhouse like the earth, the greenhouse works by physically restraining the gases so that the hot gases are kept within the confines of the greenhouse.

Greenhouse Gas “theory”

Typically websites will show diagrams like the one below labelling this mechanism as a “theory” as if it were based on some fundamental law of nature. So let’s just recap this “theory”.

Typical outline of the “greenhouse gas theory”.