The world’s energy system will decarbonise over the next three decades, says advisory services and risk management company DNV GL Africa business manager Robert O’Keefe.

Unpacking DNV GL’s ‘Energy Transition Outlook 2017’ report at the Nordic Energy Days conference, in Pretoria, on Thursday, he noted that, 30 years from now, total energy-related carbon dioxide would be half of what it is today.

“Energy demand will plateau after 2030, mainly owing to efficiencies in the generation and use of energy, even as the world makes steady progress with the United Nations Sustainable Development Goals,” O’Keefe said.

The report points out that oil and coal currently provide 29% and 28% respectively of the world’s global energy supply.

“By 2019, coal will be overtaken by gas and, in 2034, gas will surpass oil to become the largest energy source,” he noted.

O’Keefe pointed out that fossil fuels’ share of the world’s primary energy mix will decline from 81% currently to 52% in 2050.

Hydropower, biomass and nuclear will remain flat, while solar and wind will grow rapidly and represent 13% and 14% respectively of the world’s primary energy supply in 2050, he noted.

O’Keefe further noted that the estimated energy demand by mid-century would be 430 exajoules (EJ), up from 400 EJ in 2015.

He noted the modest 7% increase contrasted with the 35% rise in global energy demand that has occurred over the last 15 years.

The slowdown in demand growth, he said, was related to a decelerating population, slow productivity growth and faster improvements in energy efficiency and electrification in heating and transport.

“Our forecast shows a more dynamic transition on the supply side of the equation, with renewable energy growth leading the charge.”

Other rapid changes include shifts in shale gas and falling coal demand in China and other developing countries, he noted.

“The key issue, however, is rapid changes within the electricity mix,” he said.

He highlighted that renewables will contribute the lion’s share of global electricity generation.

With this high amount of variable power, the stability of the electricity system will become crucial.