02082011

What is climate change?

Climate change simply put is a natural process where the climate changes over time. This change is caused by one of three classes of 'variable' on the climate:

1. The Climate itself

The actions of the climate itself causes change, this perhaps is easiest to observe in a short time frame, as aspects of climate like wind and rain regularly change on a small scale. These aspects then in turn can, under the right conditions, group together to contribute to larger weather events, such as cyclones, droughts and floods.

2. The Planet

Lets not forget that the planet we are one is not a static object, over longer times frames (such as thousands to millions of years) the global topology changes - this effects the flow of the seas and also where on the global the land 'sits' - this in part determines if a land is to be wet and fertile or dry and desolate. Also the weather itself through weathering changes the very land profile.

3. The Solar System

The Solar system, and in particular the Sun, plays a very big part in our climate. We live in a distance band from the Sun called the 'Goldilocks zone' - not too hot and not too cold. That 'zone' shifts back and forth slightly over time as the Sun ages. This combined with our elliptic orbit that changes shape over time, means we slightly shift back and forth within that zone. The net effect of this is over a long time period is the Sun slightly heats the Earth, then slightly cools the Earth. Also the 'tilt' of the Earth with respect to the Sun shifts slightly over time as well, this causes the range of temperature experienced in a year over the globe to expand or contract depending on the size of the tilt...

Also there is evidence that the short solar cycles, called sunspot cycles, could have a short lived impact on the climate through variable solar energy intensity.

What about the human impact?

Yes, we do have some impact, but I think this has mostly being through land use change rather than through Co2. Basically in the last 10 years we have emitted a quarter of all Co2 emitted by man since 1751 - yet there has being no increase in global temperatures across those 10 years.

Also it has been shown that Co2's effect on global temperature is logarithmic in nature, i.e. every doubling in Co2 results in roughly a 1 degree increase in global temperatures. So to get 1 degree of warming now, global Co2 needs to go from around 400ppm to 800ppm, given that it took 40 years to go by only 80ppm, it would take 200 years to get that to happen at current rates of Co2 production.

There is also the question of whether we are measuring the right Co2 anyway...

Personally I think pinning the tail on Co2 is the totally wrong thing to be doing, which is one of many reasons why I'm against the Carbon Tax in Australia