A "happy divorce" between carbon emissions and economic growth is necessary as people flock to urban areas, a new report finds.

Kamel Ben Naceur from the International Energy Agency (IEA) presented the organisation's latest report, Energy Technology Perspectives: Towards Sustainable Urban Energy Systems, at Imperial College London last week, in a special lecture hosted by the Grantham Institute - Climate Change and the Environment, and Energy Futures Lab.

Reducing greenhouse gas emissions from fossil fuel energy is essential to keep average global warming to below 2^°C, and the new report finds that built-up areas are critical as urban populations use more energy per person than rural ones.

The report found there are many opportunities to cut energy use in urban transport, and in buildings' construction, or services such as heating and cooling - whilst boosting opportunities for sustainable economic growth. Recent advancements in cost-effectiveness and efficiency or renewable energy technologies, especially of solar power, show how new and improving technologies can help people to capitalise on this sustainability revolution.

Mr Ben Naceur, Director for Sustainability, Technology and Outlooks at the International Energy Agency, was eager to highlight the leading role for cities in developing countries, many of which are yet to be transformed into modern conurbations.

"These cities can reap many benefits from reducing emissions, including economic gains as a result of technological innovations, and health advances as harmful airborne pollution is reduced," he said in his presentation.

The report particularly identifies potential for technological development in the areas of: biofuels, which produce fossil fuel-alternatives from organic matter; and carbon capture and storage technologies, which filter out the most harmful greenhouse gases before they reach the atmosphere.

Developing nations are not the only ones responsible for tackling climate change, however, and the report also focuses on the importance of integrating local, national and international policies.

Mr Ben Naceur explained that any countries' governments can lead the way in lowering emissions. For example, he said, Norway has brought in a range of complementary policies support the take-up of electric cars. Here, a high proportion of the population have been encouraged by government subsidies, a proliferation of charging points for vehicles, and other local policies.

Mr Kamel Ben Naceur (L) and Prof Martin Siegert of the Grantham Institute (R)

Professor Martin Siegert, Co-Director of the Grantham Institute, said at the event, "In the future, climate change may have a disproportionate effect on urban areas. Low-lying cities will be susceptible to increased flooding and rising sea levels, many are situated in areas already at risk of severe heat-waves and droughts, and changing weather patterns will affect stable supply-chains and affordable sources of food.

"With an even greater proportion of the world’s population moving to cities, urban planners must continue to strive for sustainability. Delivering the UN's Sustainable Development Goals for cities and communities, climate action, good health, responsible consumption will mean a more prosperous future for all.

"Now it is of greatest concern that the global community acts together to reduce greenhouse gas emissions and limit the effects of climate change, and that scientists and engineers continue to carry out research to adapt to the consequences of a changing environment."

Reporting by Katie Scott.