Energy intensity is widely defined as being the energy efficiency of a nation’s economy, based on consumption per unit of GDP. Generally speaking, as a county’s GDP increases, so its energy intensity decreases.

However, the most recent findings from the EIA have shown that countries in the Organisation for Economic Co-operation and Development (OECD – the intergovernmental economic organisation of 35 countries), used on average 12 per cent less energy per unit of GDP in comparison to non-OECD nations.

This is predominantly due to the nature of their economies. OECD countries tend to have larger service-based models, which are less energy-intensive and more financially rewarding when compared to the manufacturing-focused economies of most non-OECD countries.

With society becoming ever more globalised, there has been a shift in responsibility for manufacturing to countries with poorer economies. Many of these are facing huge increases in their cost of production – for example, India has faced 30 per cent increases in labour costs since 2010. As a result many have had to cut costs, a move that subsequently usually reduces energy consumption. This explains why non-OECD countries have seen a -40 percentage change between 1990 and 2015. Conversely, OECD countries have only seen a -28 percentage change.

‘Well designed and targeted regulation can have a significant impact on our energy consumption,’ Greg Shreeve from the Energy Saving Trust told BBC News. The EIA concluded that countries with more developed economies tend to have these more stringent regulations.

‘Generally countries that become more prosperous, develop legislation/energy efficiency targets or invest in more energy efficient equipment, ie energy, becomes more of a priority,’ says Dr Charlotte Adams, a lecturer in geography at Durham University. ‘Developing countries do have an opportunity to learn from the progress of developed countries and there are some arguments to suggest their development may be less energy intensive because they can benefit from recent improvements in technology and practice.’

Domestic energy consumption is also a key player contributing around 30 per cent of total energy consumption in the UK. The Department of Energy and Climate Change reported that since 2000, energy consumption per household has fallen by 27 per cent. This is perhaps surprising considering the increase in household wealth and boom in consumer electronics.

However, there are parallel efficiencies. The average light bulb consumes 29 per cent less electricity in 2013 than in 2008, a new fridge-freezer uses 73 per cent less energy than its equivalent 20 years previously and, between 2004 and 2013, the number of homes with loft and cavity wall insulation increased from 39 to 67 per cent.

Energy productivity – the amount of economic output per unit of energy consumed – was also measured in the EIA’s report with most countries and regions showing an increase over the last 25 years. With an increase of 133 per cent, China easily topped the tables.

‘In more than 20 per cent of countries energy productivity is decreasing (mainly in the Middle East, Africa and Latin America),’ stated a report on global energy efficiency published by ABB, a European power and automation supplier.

The EIA’s figures show that the Middle East has seen a decline in energy productivity at a rate of -6 per cent. This is likely to be the result of increased reliance on energy-intensive industries, low energy prices and not surprisingly their widespread dependence on air-conditioning.

Generally, the countries showing negative energy productivity have smaller economies, while China’s impressive increase in energy productivity was due to the fact that its increase in economic output was double that of its energy consumption.