It is desirable to reduce greenhouse gas emissions so that the greenhouse effect doesn’t get out of hand and warm the world by amounts not seen for millions of years.

And should this warming happen too fast for our production systems to adjust, then desire must become an imperative.

Fair enough.

Now let’s consider the size of the task.

If we convert the current global energy use into oil equivalents – that is combine all the coal, oil, gas, hydroelectricity, nuclear and alternative sources and convert the energy we gain from them into the energy we get from a barrel of oil – we use the equivalent of 10 million barrels of oil an hour.

Or, if you prefer, 1,590 million litres an hour.

That’s enough to liquid to fill over 15,000 Olympic sized swimming pools every 24 hours or in less than two weeks fill Sydney Harbour, onE of the largest natural harbours in the world.

Plus this number is, believe it or not, getting larger by the day thanks to more people and rapid growth in demand from emerging economies.

10 million barrels an hour is colossal demand. No wonder superannuation funds invest in fossil fuel energy.

Perhaps the next time you lounge with a G&T by a swimming pool, imagine the pool, and a few thousand more, full of oil, and you may glimpse the size of the task.

Our energy demand is simply vast. And thanks to availability, some legacy issues and economics, most of this demand comes from fossil fuels. Partly because of the volume and locked in infrastructure for generation and delivery energy generation is a tough thing to shift, requiring huge investment in alternative sources, a clunky transition period, and unbridled commitment to change.

And because it will take time, any shift will require great tenacity.

It is a big ask and very unlikely that we will take on this transition voluntarily. It will be both difficult and costly. The engineering task alone is staggering: reworking energy grids, distributed generation, engine conversions and replacement. Even the decision to keep the grid or move to a distributed model is a big one.

Then there is the economics. New monies must be found to develop alternatives at scale and monies found to support uptake of what will initially be more expensive energy sources. Then those who have already invested heavily in fossil fuel power risk lost dividends, losing out to new investors. And more of us have invested than we might realize. Superannuation funds that will pay out for many a retirement, like the low risk of traditional energy investments.

The US and Europe are oil and coal dependent because their entrepreneurs and investors backed fossil fuels. New wealth in China, India and South America can be more flexible. They will invest for the far side of the transition, in the new technologies, not the status quo. In 100 years time it is unlikely that the old west will hold the purse strings, which is actually ok, if a little scary for those who have already invested.