



An everyday experience for many of us is getting in a lift (or elevator) - every work day I do this at least 4 times a day, as I am one of those people that prefers to leave my place of work at lunchtime and breath some relatively fresh air.





The next time that you take a lift make a note of the lift capacity. This is the number of people that the lift is rated to carry, and the total weight of those people. This is a simple (yet surprisingly variable) way of determining the average weight of a human being (number of kg divided by number of individuals).





Now, the next step is to imagine that human population growth (that is, population growth at a perceptible positive rate) is somehow desirable. For the moment, assume historical rates of global human population growth. Here we are talking about growth rates between 1% and 2% per annum. It sounds relatively harmless, doesn't it? Unfortunately, it isn't. Using the Rule of 70 it is easy to calculate that at 1% a population doubles every 70 years and at 2% it doubles every 35 years. This is how our global population doubled from 3 billion in 1960 to 6 billion in 1999 - just 39 years.





Take any average human weight between 65 kg and 80 kg (which is what most lift designers seem to assume) and you will find that our global human population would outweigh the Earth in just over 1500 years at a 2% annual growth rate or over 3000 years at a 1% growth rate. I've described this scenario in more detail in my article on Human Global Ecophagy





In evolutionary terms this is the blink of an eye.





We are assured by the UN and other "authorities" that human population growth will "stabilise" at something like 0.5% per annum by 2050. This is not good enough.





I ask you to get the facts for yourself, and do the math. You will find that no positive rate of population growth - not even a variable positive growth rate - is remotely sustainable.





Essentially we have two options, which are not mutually exclusive:

We can learn to live sustainably on Earth, which means at growth rates very close to zero.

We can learn to live and grow in space at positive growth rates. Personally, I would prefer that we learn to do both. The first option, alone, is too depressing to contemplate. The second option, alone, is irresponsible if we care about life on Earth.

Thanks for reading,

David Coutts

We are all regularly referred to as consumers, but have you ever taken this concept to the extreme? Well, if not, imagine humanity consuming the entire planet. This blog will explain how an everyday experience can start you on your way.