By 2030 the demand for resources will create a crisis with dire consequences, Prof John Beddington said.
Demand for food and energy will jump 50% by 2030 and for fresh water by 30%, as the population tops 8.3 billion, he told a conference in London.
"There's not going to be a complete collapse, but things will start getting really worrying if we don't tackle these problems."
Prof Beddington said the looming crisis would match the current one in the banking sector.
"My main concern is what will happen internationally, there will be food and water shortages," he said.
The United Nations Environment Programme predicts widespread water shortages across Africa, Europe and Asia by 2025.
The amount of fresh water available per head of the population is expected to decline sharply in that time.
The issue of food and energy security rose high on the political agenda last year during a spike in oil and commodity prices.
"We can't afford to be complacent. Just because the high prices have dropped doesn't mean we can relax," he said.
Improving agricultural productivity globally was one way to tackle the problem, he added.
At present, 30-40% of all crops are lost due to pest and disease before they are harvested.
Professor Beddington said: "We have to address that. We need more disease-resistant and pest-resistant plants and better practices, better harvesting procedures.
"Genetically-modified food could also be part of the solution. We need plants that are resistant to drought and salinity - a mixture of genetic modification and conventional plant breeding.
Better water storage and cleaner energy supplies are also essential, he added.
He doesn't really offer any concrete solutions except for the possibility of genetically modified crops. I do like how he actually speaks about the physical limits on human growth. Often times in the developed world we talk about global warming and energy issues, but we forget about the fundamental things like population growth and it's effects on food and fresh water demands. Obviously, global warming and energy issues will affect food and water scarcity, but we should be careful not to confuse proxies with the actual fundamental issues that we should be concerned with.