by Jeffrey Sachs
Energy lies at the heart of the world’s sustainability challenge. On the one hand, abundant, accessible, low-cost energy is vital for economic prosperity. On the other hand, the world’s pattern of energy use, based on fossil fuels, threatens massive future climate change with devastating potential consequences. The greatest sustainability challenge, therefore, is to meet the energy needs of a growing world economy while moving to a safer pattern of energy use.
The difficulty can be explained in the following way. Currently, the world energy system uses the equivalent of around 170kg of oil in primary energy for every $1,000 (Dh3,678) of output, if one adds up the annual use of oil, gas, coal, nuclear and renewable energy and converts each primary energy source into units of oil equivalent. On an average, each unit of primary energy (again measured in tonnes of oil equivalent) contributes 2.4 tonnes of carbon dioxide (CO2) into the atmosphere. With a world economy of around $90 trillion, measured in purchasing-power adjusted prices, the result is around 36 billion tonnes of CO2 emitted into the atmosphere.
The basic tendency is for CO2 emissions to grow. This is because the world economy is growing around 3-4 per cent per year. That global economic growth is vital for the well-being of at least 6 billion of the world’s 7.2 billion people — notably those living in developing countries. Energy forecasts made by the International Energy Agency, the US Energy Information Agency and others point to the likelihood that global emissions could reach 50 billion tonnes of CO2 per year by 2050, if not higher.