Weather School: A climate discussion.

It's easy to think that the global warming isn't happening when it gets colder where you live, but we need to remember it's global so even if it gets colder at your place the global temperature can still increase.

Global warming can be divided in two categories; man made and naturally global warming. Many global warming skeptics are using the fact that the sun has different kind of cycles and that for example they say its due to solar spots. Of course solar variability are affecting the climate, but the changes of the temperature can't be fully correlated with the warming. We also has volcano eruptions, but none of the latest volcano did affect the global temperature.

Some of the skeptics even doesn't fully understand the greenhouse effect, and mostly of the scientist that doesn't believe in that the anthropogenic emissions is the cause of the global warming is in a minority. This article (http://www.pnas.org/content/early/2010/06/22/1003187107.abstract) found out that most of the scientist that isn't a 'believer' doesn't actively publishing in this field. I think that's interesting, wonder why? I won't answer that and instead let my readers think about that.

In spirit of the climate discussion I will try to explain the greenhouse effect in several simple ways. I start with the easy and probably the most used way:

We can compare the greenhouse gases with a coat, it works the same way holding the heat inside, making the temperature increasing. This might easily explain the effect, but it can be harder to explain why increased anthropogenic gases would make the temperature increase. The easiest way is to think about it like you another coat on earth. More greenhouse gases means more 'coats'. Pretty simple and explains the essence of the greenhouse effect.

But my favourite explanation is one I learned from one of my teachers. It is still very easy to understand but you can explain a lot more than with the 'coat' explanation. We start with imagining a pub and a little cabin, between the cabin and the pub is a thick forest. If we imagine the forest as the greenhouse gases and the cabin as the open space. The heat or infra-red radiation can then be a drunk person leaving the pub, heading for the cabin. What happens when he walks through the forest? He will have trouble walking in a straight line and 'bounce' between the trees, if the forest is thicker he will have a lot harder to walk through the forest. This is how the greenhouse effect works, with more gases the heat will stay inside the atmosphere longer and heating up it more.

A more scientific explanation talks about 'windows' of radiation that depends on the structure of a molecule. A greenhouse gases has a specific structure that makes it absorb long-wave radiation (heat).

I hope you think this was an interesting reading, please comment and tell me what you thought about it or if you have a question.

//Osced