Real increases in food prices will be one of the biggest challenges for global policy makers in the coming decades, delegates were told at an inaugural Norfolk farming lecture.

Retired agricultural economist Sir John Marsh, who delivered the first global food lecture at Colney's John Innes Centre, said that policy makers and political leaders would have to make some tough decisions.

'They are going to have to make decisions about making changes. They will have to have the nerve, the courage, the determination and a resolution to face up to those who stand in the way of accepting any change at all,' he said.

Sir John told 220 people at the Centre for Contemporary Agriculture lecture that political will would be needed to make decisions, which challenged the interests of those set in a 'very comfortable cosy nook'.

In his analysis of the Foresight report, published earlier this year, he said that raising food production was a major challenge. 'We know that agriculture and the food system as a whole are a very significant contributors to pollution,' he said.

The report suggested reductions in emissions could be made 'by incentives, by regulation, by consumer pressure, by efficiency gains and by corporate responsibility. We need to make people aware and then they make their decisions about production and the cost incurred in these fields,' said Sir John, who was director of Reading University's Centre for Agricultural Strategy.

A boost for local food production made sense in many economies by introducing new technologies but the ecological and social impact also had to be considered.

'We know that the chance to deal with that may conflict with other goals – particularly the goal of producing more food in some countries, which often impacts on income growth in poor countries. We know that with actions of these sort the costs tend to fall disproportionately on poor people.'

While Britain and Europe has some international commitments on environmental policies of one sort or another, there were relatively little in terms of dealing with problems relating to labour and migration routes.

'We will, therefore, need discussions, implementation and agreement at a global level. The World Trade Organisation is important and we don't want to rebuild barriers to trade and impoverish ourselves as a result.'

'It will be inescapable that we take note of the importance of the management of multi-national companies which are beyond the remit of any one nation to control.'

In the past 50 years, food prices have fallen in real terms. But Sir John forecast a real rise in food prices. 'And that, for the people at the bottom of the world's income level, that is a really worrying concern,' he said.

Sir John welcomed the initiative launched by Norfolk farmer Philip Richardson, of Downham, near Wymondham.

As a board member of the CCA, Mr Richardson said that one aim was to deliver degree and post-graduate courses to match the needs of agriculture. 'The UK and the world faces enormous challenges to feed the further generations. Many will remember when huge government resources were given to agricultural science and food production. In the UK and much of the world, we became overly complacent about our ability to feed the world,' he added.

With the lack of investment in education, he said that in the UK and in many other countries, an entire generation of scientists and advisers had been lost.

A former award-winning pig farmer, Mr Richardson, said: 'For many years, knowledgeable people have tried to shake governments and populations out of that complacency.

'It took the 2007/8 food price spike really to make political difference and draw attention. Even then, in western countries, some people said that it won't happen here. It actually did and it might be happening just now.'

The second lecture in the series will be given by Dr Jim Sumberg at the John Innes Centre on January 19.