Here are some initial thoughts about how our climate works, and what it has been like in the past.
How would you define climate?
I think climate is the range of weather to expect in a particular region. For example, if we talk about the climate of the British Isles, and wanted to define how it differs from the climate of Central Europe, we would look for average temperature and the patterns of rainfall and wind across the different months of the year. I would expect those averages to be from about 50 years of data, as I know in the British Isles our weather can be very variable from year to year.
How big is the earth?
The surface of the world is 510M km2 or 196M miles2
If we could measure the temperature of every 100km2 (that’s a square 10km x 10km) we would have to measure 5.1M squares.
In miles, if we do the same for every 100 square miles (squares 10mile x 10mile) thats 1.96M squares.
That’s quite a challenge. If we go to 100km x 100km which is an area of 10,000 km2 there are 51,000 to monitor.
In miles if we go to 100mile x 100mile squares (10,000 square miles) there are 19,600 to monitor.
And what are we measuring? Air temperature. That changes a lot every day.
Now think about the oceans, which cover 2/3 of the earth’s surface. Water heats up and cools down slower than air or land (although rocks can be a store of energy which they release slowly too). There are patterns in the ocean currents that take decades or more to work themselves through.
How do we understand/find out/measure what causes changes in our weather patterns?
The main driver for weather patterns is the energy of the sun that arrives on planet earth (there is also heat energy coming from within the earth that gets to the atmosphere through volcanoes and the oceans).
The warming of the sun drives patterns of air circulation in the atmosphere, and currents in the oceans. It provides energy for rainfall. Some of the variables in these processes:
- changes in the sun’s activity and the amount of energy it emits
- changes in the atmosphere will affect how much of the sun’s energy is reflected or absorbed
- clouds, particles like ash from volcanoes, gases like CO2 and methane
- heat radiating out from the earth will affect our temperature – this depends on the different surfaces of the earth – water, rock, soil, vegetation cover.
- activity of volcanoes under the ocean
I hope these questions set the scene for us – the world is vast. The measurement and definition of global climate is a vast undertaking. Predicting how global climate may change in the future is a task of unimaginable complexity.
The factors that work together to determine the temperature of the world are many and complex.