How did we come to depend so much on fossil fuels?

This is another post inspired by my current first year physics course, The Physics of Sustainable Energy (PHY123).

Each inhabitant of the UK is responsible for consuming, on average, the energy equivalent of 3.36 tonnes of oil every year. 88% of this energy is in the form of fossil fuels (about 35% each for gas and oil, and the rest in coal). This dependence on fossil fuels is something new; premodern economies were powered entirely by the sun. Heat came from firewood, which stores the solar energy collected by photosynthesis for at most a few seasons. Work was done by humans themselves, again using energy that ultimately comes from plant foods, or by draught animals. The transition from traditional, solar powered economies, to modern fossil fuel powered economies, was sudden in historical terms – it was probably not until the late 19th century that fossil fuels overtook biomass as the world’s biggest source of energy. The story of how we came to depend on fossil fuels is essentially the story of how modernity developed.

The relatively late date of the world’s transition to a fossil fuel based energy economy doesn’t mean that there were no innovations in the way energy was used in premodern times. On the contrary, the run-up to the industrial revolution saw a series of developments that greatly increased the accessibility of energy. Continue reading “How did we come to depend so much on fossil fuels?”

Understanding the energy debate

This semester I teach an optional course to first year physics students at the University of Sheffield, with Professor David Lidzey, called The Physics of Sustainable Energy (PHY123). This post explains why I think the course is important and some of what we hope to achieve in it.

The prosperous industrial society we live in depends, above all, on access to cheap and plentiful energy. Our prosperity has grown as our consumption of those concentrated energy sources that fossil fuels provide has multiplied. But this dependency is a problem for us; burning all those fossil fuels has materially altered the atmosphere, this has changed the world’s climate and this climate change is set to continue and intensify. We need to put our energy economy onto a more sustainable basis, but at the moment this transition seems a long way away, and the energy debate doesn’t seem to be progressing very fast. The aim of our course is to give physics students some of the tools needed to understand and contribute to that debate.

So what do you need to know to understand the energy debate? Continue reading “Understanding the energy debate”