It’s natural for gas to play key role in future energy mix

Less polluting than coal and more flexible in its possible uses, gas is an attractive option, but not everyone will be able to replicate the United States’ shale success, as Sarah Murray reports

Sustainable energy that hits back

Technologies are being developed which promise to combat climate change and generate energy from unexpected sources. Jim McClelland looks at five of the most promising

Vulnerable big miners must safeguard the environment

Sustainability for mining companies means access to new resources, but host governments and communities have other environmental priorities, as Martin Beaver reports

Race against time for cities

How much trouble are we in? What we can do about it? How long have we got? With quality of life at stake and no easy answers, the time is now for tackling the difficult questions being asked of future cities worldwide, writes Jim McClelland

Nature is back as cities go green

In the face of climate risk and population pressure, urban greening is helping to build resilience in cities and improve the health of inhabitants, writes Jim McClelland

A modern metropolis must provide its own power

Circular systems will help cities become more self-sufficient in energy and tackle the challenges of carbon, cost and security, as Mike Scott reports

Rolling through the heart of the city

From the hills of San Francisco to the boulevards of Melbourne, the tram mixes traditional appeal with modern green credentials, writes Chris Milton

At the centre of a complex web

From climate change to population growth, the pressures on food producers are intensifying. Mike Scott reports