What do we mean by climate change?
Climate change is frequently in the news these days, but what does it mean?
To address this question we need to understand what climate is. Briefly climate is a short hand way of summarizing the weather observed over a particular period of time at a particular location. Mostly we are familiar with climate averages such as average temperature or rainfall experienced at a location. But other weather factors are also part of climate such as wind, sunshine, and cloud. Furthermore although averages are useful they don’t tell the whole story. We also need to summarise how much these elements might vary during the same period. This might include their range and information about the size of extreme events and how often they occur. Internationally local climate standards are assessed over thirty year periods though for some applications shorter or longer periods are useful.
What do we mean by climate change? In general terms climate change relates to shifts in climate between different periods of time, long enough to minimize the effects of short terms variations, both locally and globally. However current interest has focused on an observed warming of the global climate over the past 150 years.