Each day in Bristol there are around 750 car trips made by community nurses to visit people in their homes, and a similar number of trips by the non-urgent patient transport service to get people to their appointments at hospital. Travel by staff, patients and visitors is taken for granted but the fact is nearly all of these journeys rely on oil.

Modern healthcare also uses a huge quantity of supplies, drugs and equipment, many of them manufactured using oil.

Diagnostic scanners, surgical operating equipment and laboratory technical equipment have changed beyond recognition in the past 50 years but all of these rely on oil in their production and use.

NHS Bristol, the body responsible for health care in Bristol, recently calculated its total energy usage as more than 3,000 tonnes of CO2. The 20 buildings the organisation manages use more than 7,300 megawatts of energy a year.

This in turn equates to over half a million pounds in bills. When you remember this does not include any of the 60 or so GP surgeries in Bristol or the city's three main hospitals, the link between oil and healthcare becomes even clearer.

Bristol and other regional health and council leaders are already looking at these issues. A report was produced in autumn last year called Building a Positive Future For Bristol after Peak Oil.

So what is peak oil and why does it matter? To understand it we need to look at how an oil field works. Put very simply, what happens is the first oil is easy to extract, and the amount produced goes up and up. Then it hits a peak and production starts to go down. Once you are past the peak then each barrel of oil gets more and more difficult to extract.

There is only so much easily accessible crude oil for humans to extract. There may be lots more oil somewhere, but if the energy needed to extract it is nearly as much as the energy you'll get from it, then the economics is very different from what we have been used to up to now.

This isn't some vague theory, it is geological fact. US oil production peaked in the early 1970s, which was 40 years after the peak in US oil discoveries. For the whole world, discoveries peaked in the 1960s. And if the 40-year time lag between peak discovery and peak production roughly applies to the world just like it did to the US, then fairly soon we can kiss goodbye to the times when we took cheap energy for granted.

So what does this mean? Well, we are not yet running out of oil (it's only half gone) but we are running out of time – to design and build the infrastructure we need for prosperity beyond oil. Behind the scenes, there is serious recognition of the problem, yet among the general public few people have heard of peak oil and not much is happening yet to address it.

In a June 2010 Risk Report Dr Richard Ward, the chief executive officer of Lloyd's insurance group, put it this way: "We have entered a period of deep uncertainty in how we will source energy for power, heat and mobility, and how much we will pay for it. Is this any different from the normal volatility of the oil or gas markets? Yes, it is… business leaders… are going to have to find a new energy paradigm."

The UK Energy Research Centre, in a thorough and careful report last October, concluded that a global peak is likely before 2030, and possible before 2020, which is actually very soon given the time it takes to research and develop alternatives.

It's hard to open a newspaper without reading something about the oil industry. The explosion in April on the Deepwater Horizon rig in the Mexican Gulf caused nearly five million barrels of crude oil to leak into the ocean. New drilling in the Arctic and extraction of oil from Canadian tar sands are causing controversy because of damage to the natural environment and the business pages are full of legal and insurance wrangles over who should carry the cost when things go wrong.

So behind these stories is the story of peak oil. This is not just about the livelihoods of fishermen in Florida. It will affect all of us sooner or later. Whether the outcome is good or bad depends on things we all do right now.

The stakes around peak oil are high. It affects how we produce and transport food and goods, how we heat our homes, how we travel, how we earn our livings, as well as how we deliver healthcare.

The key question for the NHS is if we are clever enough to design modern healthcare with oil, are we also clever enough to design a new system without it? One thing seems clear – we must try. And even more importantly, we need to start that process now because it will take time.

Dr Raffle specialises in public health who lives and works in Bristol.