Why are we asking this now?

The Government's appointed Chief Scientist and latter-day Nostradamus, Professor John Beddington, has predicted that within 20 years the world could face "a perfect storm" of food, energy and water shortages that will create a crisis of unprecedented proportions. Yesterday, in a speech to the Sustainable Development UK conference, the Prof Beddington predicted that food and energy demand will grow by 50 per cent and water supplies 30 per cent greater than current ones will be required by 2030. "There's not going to be a complete collapse," he said, "but things will start to get really worrying if we don't tackle these problems" – chief among them that the global population will grow to 8.3 billion by 2030. "This is a very gloomy picture," he concluded.

What motivated this alarming outburst?

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Prof Beddington claims that "the reason for saying all this is that if we are actually going to get science and technology in place to address the issues, we should do it now". He says he is particularly concerned that the recent collapse in oil and commodity prices, along with global recession, will encourage conservation issues to fall off the agenda. Worse, hundreds of millions of dollars worth of capital expenditure by big oil firms, invested in research into alternative energy sources, has been cut back in these hard times. He warned: "We can't afford to be complacent. Just because the high prices have dropped doesn't mean we can relax."

He also pointed out that today international food reserves are at a 50-year low, leading to price volatility, and that our strategies for storing and producing food have flaws which, by 2030, may well become fatal for large sections of the population who will starve. His concerns about water supplies, meanwhile, are echoed by the United Nations Environmental Programme which predicts widespread shortages across Africa, Europe and Asia by 2025 when the amount of water available per head of the population is expected to decline sharply.

This all sounds pretty depressing. What about climate change?

There's no escaping this. Climate issues play a crucial role in Prof Beddington's "perfect storm" thesis. In the first instance climate change will have a transformative effect on the shape of the world. There is already melting of the tropical glaciers and significant decrease in the Arctic ice cover. On Wednesday some scientists at the Royal Society voiced concerns that the Arctic could be free of ice by the summer of 2030. "These issues really have to be addressed in combination," concludes Prof Beddington. "You can't address the food security issue if you ignore water or climate change. Similarly, you can't address climate change if you ignore the fact that the world needs to feed itself and actually use energy supplies."

How will all this effect the UK?

In essence, Britain is relatively lucky, with our temperate climate we are unlikely to suffer dramatic food shortages but if we do not create better food reserves we are likely to suffer volatile prices. We might also expect to see greater rainfall, higher temperatures and more pests. These climate changes could, however, mean that northern Europe, Britain included, will become a new key centre for food production. Further afield the picture looks bleaker with shortages and climate change affecting the poorest countries in the world most dramatically. In Africa, for example, there are predictions that between 75 and 250 million people could be effected, especially in those countries that rely on farming. Some estimates suggest that some African harvests could yield half what they currently do by 2020. Furthermore, the UN estimate that up to 50 million people could become "environmentally displaced" by the effects of climate change – putting more pressure on already over-populated cities.

So what can we do to save ourselves from this doom-laden scenario?

By 2030 there are some obvious steps we should take which would include establishing greater co-ordinating efforts to clean water, and save it; to establish better food reserves and global energy security. But there is fierce debate about how best to achieve these ends. To give just one example, governments are increasingly keen to create new nuclear reactors, which they say are provide clean and green energy. Some argue the reverse – that the amount of energy required to mine the Earth's limited uranium reserves is massive, while plans for next-generation "fast-breeder" reactors, though more efficient, will create significant amounts of plutonium waste.

There are other debates over genetically-modified crops, and perfected species which some label "Frankenstein Foods" but which may hold the key to growing more food on less land. Only yesterday the "Stress Tolerant Rice for Africa and South Asia" project announced pioneering research in Burkina Faso, Ghana, Guinea and Nigeria of 80 varieties of rice designed to survive in the iron-rich soils of West Africa. We must settle these issues quickly if we are to find a way to thrive in the long term.

And what about in the short term?

We have already seen the ravages caused by spikes in food costs. In 2007, global wheat prices rose by 77 per cent. One observation made by Prof Stephen Hopper, director of the Royal Botanical Gardens at Kew, is that the world relies too heavily on a tiny number of key species of plants for food. Last month he urged British farmers to enlarge the range of crops they grow to safeguard future supplies. There is also a growing body of evidence that biofuel crops may actually cause food prices to rise.

What about politicians? Can they help?

Well, the jury is out until G20 and the next international summit on climate change in Copenhagen this winter. But there are some rapid political changes that can be made. Prof Beddington believes that apart from national scientific advisers, the InterGovernemental Panel on Climate Change, Climate Scientists at all the world's leading universities and, of course, the UN, there is an urgent need for "brutal" scientific advice from nominated scientists at an European level. This might help settle some of those issues.

Isn't this suggestion just more 'jobs for the climate change boys'?

President Obama has placed a great deal of importance on science, appointing three leading scientists to his advisory council as well as leading scientists like Steven Chu at the Department of Energy, and Jane Lubchenco at the Oceonagraphic and Atmospheric Administration. This contrasts with the European Commission which has no formal adviser. Among member states only the British and Irish government's have Chief Scientific Advisors.

Should we be scared?

Even Prof Beddington admits that his predictions are "bleak" – crises in climate, food, energy and water could indeed conspire against us, but there are a range of "externalities" he does not consider. These include technological advances in the fields of information systems, battery production, and alternative energy supplies – which will lead to massive efficiency savings across all sectors of the global economy. Similarly, human behaviour – from plastic bag use to car-emissions – are already helping to save energy and more will soon follow. But neither of these factors play a role in the "perfect storm" hypothesis.

Will we be living in a dystopian nightmare world within 20 years?

Yes...

* By 2030 we may lack about 50 per cent of the food and energy we need to sustain everyone on the planet

* Millions of people may have been displaced from their homes and nations by water shortages

* It is more than conceivable that critical shortages of resources will lead to global instability and war

No...

* Don't take scientists' scare tactics too seriously. By overstating their concerns, they receive more funding

* A raft of technological advances and efficiency savings will ensure that the worst aspects of climate change are ameliorated

* We will certainly not become extinct – nature always finds a way