Ed Davey has warned climate change will amplify the risk of conflicts over dwindling resources, heightening pressure on global leaders to agree international action to combat the threat.

The energy and climate change secretary yesterday outlined how territorial changes due to climate change could put pressure on trade routes and disrupt supply chains. Meanwhile, food, water and energy supply problems could “spark internal unrest that spills outwards”.

Speaking at an event at the Foreign Office, he told an audience of diplomats and foreign policy experts that they face a challenge in highlighting climate risks to the public.

“For too many people, climate security is about making sure you always have an umbrella with you,” Davey said. “For people who don’t live on the climate frontline, talk of 2030 projections and 2050 pathways can make the threat seem remote, but it’s not. If we’re going to stop talking about building a sustainable economy and start doing it, we need to take the public with us.”

Davey said that the world has to reach peak global emissions in less than eight years’ time in order to avoid the worst impacts of climate change. He added it also necessary to “rewire the global economy” to use resources more efficiently while growing the economy.

“The decisions that will shape the decades to come are being taken now, in boardrooms and staterooms around the world,” he said.

“Many of the homes, the cars and the power stations we build today will be operating in the middle of the century. We are choosing our future now, but most people don’t realise it.”

Davey warned food demand is predicted to grow 70 per cent by 2050, while 1.8 billion people will live in areas suffering from absolute water scarcity in just 15 years’ time. These economic and environmental challenges come against a backdrop of commodity price increases of nearly 150 per cent since the year 2000.

He went on to quote a study that found a one-degree rise in temperature will render almost two-thirds of maize-growing areas in Africa less productive, which makes climate diplomacy and the agreement of international action to reduce emissions “all the more urgent”.

“Where the risk of conflict already burns brightly, [climate change] will focus the flame,” he warned. “Those parts of the world we are most concerned about – the conflict flashpoints, the fragile trade routes, the weakened democracies – are often the same places that will be worst affected by climate change.

He added that businesses and politicians have a key role to play in managing and reducing global climate risks. “We need to build resilience and adaptation into developed and developing economies alike,” he said. “And we need to get that global deal to stop emissions rising. If we do not, a whole new set of problems arise.”

His speech came as a US intelligence report predicted scarce water supplies are likely to fuel instability in regions including South Asia and the Middle East.

While the report said a “water war” is unlikely in the coming decade, the risk of conflict will grow with global water demand, which is likely to outstrip current sustainable supplies by 40 per cent by 2030.

The Defense Intelligence Agency said water shortages and pollution will also hamper the economic growth of important US trading partners by limiting the use and development of hydro power, which is an important source of electricity for many developing countries.

In a speech yesterday, secretary of state Hillary Clinton emphasised that the US considers these risks – as well as the possibility that terrorists may target vulnerable water infrastructure – to be critical.

“These threats are real, and they do raise serious security concerns,” she said.