Given the extra-ordinarily powerful role that numbers play in our lives, it is surprising how few people are really comfortable with them or can readily absorb what they mean.
Let's start by considering "scale" and "growth".
"Scale" is simply what happens when you keep adding numbers together.
Each unit adds the same amount to the total, so it appears to be a linear process: that is it keeps progressing in a straight line.
This is true, but what really is the effect of adding zeros to the end of a number? Just how much bigger than a million is a billion? The obvious answer is that it is 1,000 time bigger but what does that actually mean? Consider for a moment seconds as a unit of adding up.
Each second last the same amount of time but what is the difference between 100,000 seconds, 1 million and 1 billion of them? If we convert the seconds into the bigger units of days and weeks, 100,000 seconds is just over a day in length at 27 hours 47 minutes, 1 million seconds is just over a week at 11 and a half days but 1 billion is nearly 32 years! Yet each time the units were adding up one second at a time! Now let's look at what happens when thing grow in percentage terms.
There is an old story about a Chinese merchant who did a big favour for the Emperor who was extremely grateful and offered the merchant whatever riches he wanted in return.
The merchant, not wanting to appear greedy said that he was concerned about the future for his family and, while he was making a reasonable living today, he wanted to preserve the future.
The Emperor thought this to be a magnificent display of selflessness and said he would agree to whatever request, so long as it was reasonable.
The merchant then asked that the Emperor simply provide him with a growing amount of rice as dictated by a chess board.
In the first year he simply wanted one grain then in the second year and each subsequent year double the quantity that had been given in the previous year (so 2 grains in year two, 4 in year three, 8 in year four and so on).
Again the Emperor thought the man was being reasonable and agreed.
The first few years were ok, but then the size of the debt really started to mount up.
Remember that there are 64 squares on a chess board.
A grain of rice weighs a fraction of a gram: in fact, you need about 25 grains just to make up one gram.
But small things add up: by the time 35 years had passed, the amount of rice required to pay the debt would be greater than all the rice grown in the modern world.
Even if the Emperor had had an inkling that he was being tricked and ordered that the first grains of rice be cut in half, he would only have delayed the outcome by 1 year.
When you consider that the Earth is a finite place and then think about the impact of percentage growth, it is easy to see where the fundamental problem lies with our current economic system: it simply cannot be sustained.
Bringing about change in a system as complex as the modern economy requires many thinks to come together to act in a concerted way so that some form of "tipping point" can be reached.
A "tipping point" can be thought of a bit like a watershed, when the water stops flowing, say, west towards the sea and starts to flow east.
Spotting tipping point is really quite difficult but for those who like to play with numbers, October 2010 has a few claims to have been one.
October 2010 was an unusual month in that it had 5 Fridays, Saturdays and Sundays something that only happens every 823 years.
It also had a date when the time, day and year become synchronised regardless of how you write your calendar so for the UK, 8:10 pm on October 20th became 20:10 on 20/10 in 2010: The US version occurred earlier in the day when 10:20 am became 10:20 on 10/20 in 2010.
The 10th of October was another notable day with 10/10/10 being celebrated as the "Meaning of Life" day, a reference to the fact that 101010 in binary notation equals 42, which readers of the Douglas Adams sci-fi fantasy recognise as the answer to the ultimate question of life, the universe and everything (which, in turn required the ultimate question to be discovered as "What do you get when you multiply 9 by 6?").
10/10/10 was also a day a mass mobilisation on climate change when 7,347 events took place in 188 countries as ordinary people the world over worked on projects to reduce their carbon emissions and to call on politicians to get to work on the issue.
The day was organised by 350.
org and the number 350 has real significance.
Global warming is driven by greenhouse gases present in the atmosphere and whose concentrations are being increased rapidly by human activity, mainly the burning of fossil fuels but also by cutting down forests for grazing and crop land.
Over almost the entire period that humans have been alive on the planet, the concentration level of CO2, the main greenhouse gas, has been relatively constant around a level of 275 parts per million (ppm).
This has been a useful amount and has allowed us to enjoy a relatively benign climate.
Since we started using fossil fuels about 200 years ago, the level of concentration has been climbing and climbing until it now stands at 388 ppm.
Scientists are now saying that's too much - that the extra heat that will get caught in the atmosphere at this level number will wreck havoc with the global climate.
Already we can see measurable impacts.
Glaciers everywhere are melting and disappearing fast-and they are a source of drinking water for hundreds of millions of people in Asia and South America.
Drought and heat waves like the one experienced by Russia in2010 are becoming much more common, making food harder to grow in many places.
The oceans are growing more acidic because of the CO2 they are absorbing, which makes it harder for animals like corals and clams to build their shells and skeletons.
Coral reefs could start dissolving at an atmospheric CO2 concentration of 450-500 ppm.
The Arctic is one of the clearest signals that climate change is occurring much more rapidly than scientists previously thought and is presently losing ice at a rate consistent with the "worst case" scenario in the international reports.
To get things back to within a safe climate range, we need to get off fossil fuels as quickly as possible as our energy source and replace them with naturally generated energy: wind, solar, wave.
There is enough solar energy hitting the planet in just one hour to power all of human activity for a year.
It just needs a dedication to harnessing it.
The arguments for keeping the status quo are usually couched in numbers in terms of money.
But we make up the rules of how we do the accounting in just the same way as 101010 can be read as 42.
Tell your politicians that you want a new set of rules so that the number that counts is 350.