A permanently manned base on the Moon, memory implants in the brain, the rise of a Chinese scientific superpower and unlimited, pollution-free energy. They sound like science fiction, but could they come true in the 21st century?

Predicting the future is a notoriously risky business, yet teams of experts have given their considered opinion on what to expect in the next 50 years in fields ranging from brain chemistry to space travel.

Yesterday, the Government published a series of 246 insights or "scans" into the future based on the knowledge of hundreds of specialists drawn from industry and academia known to be at the cutting edge of new developments.

Their scans covered everything from the social and economic effects of financial shocks on the international currency markets to the implications of medical breakthroughs in genetic technology and the increasing influence of an ageing population.

Sir David King, the Government's chief scientific adviser, acknowledged how difficult it was to see beyond the next 10 or 15 years in terms of scientific developments but nevertheless, he explained, there was still a rationale for scanning well beyond the known horizons.

"These scans are tools for government to identify risk and opportunities in the future. We're not in the business of predicting the future," Sir David said.

"But we do need to explore the broadest range of different possibilities to help ensure government is prepared in the long-term and considers issues across the spectrum in its planning," he said.

As the 21st century unfolds, we can expect to see the rise of China as a scientific superpower. As Chinese science develops in the next 20 years, the goods made by the world's manufacturing powerhouse will become more sophisticated and high-value.

Other emerging countries are expected to include Singapore, South Korea and Brazil, which will compete for the leading minds in science and engineering. The 20th century "brain drain" to North America and Europe will give way to "brain circulation" in which the best people move from one country to the next, competing in a global market.

The insights are published by the Government's Horizon Scanning Centre, which is part of the Foresight Directorate within Sir David's Office of Science and Innovation.

There are two types of scan: a "delta scan" containing 100 short expert reports exploring future developments in science and technology, and a "sigma scan" of 146 short papers drawing on current work and aimed at identifying future issues and trends across a wide spectrum of public policy.

Medicine

Medical developments such as stem cell therapy and RNA interference will continue to make progress in the coming decades. They will offer hope of treating incurable conditions, and could eventually lead to cures that were thought impossible only a few years ago.

Other developments in biology, however, could lead tomore fundamental rebuilding of our minds and bodies. Computers for instance will shrink, making it possible for them to be made small enough to be built into a body. The idea would be to implant chips under the skin or even devices into the brain to improve physical or mental performance. Extensions of the nervous system could improve the lives of the disabled and the able bodied.

"While optoelectric implants can restore lost vision, they could also be used to give people the ability to see outside the visible spectrum ... Although aural implants and pacemakers ... are already in use, significant resistance to implantable devices may persist due to social, moral, ethical and religious objections," it says, adding that "the majority of human computational extensions may be more l ike an exoskeleton".

If any country is likely to lead the revolution in wearable computers it is South Korea, where high broadband use and the world's highest rate of plastic surgery provide the medical and technical infrastructure to meet the demand.

Environment

Climate change seems inevitable but just how bad it will eventually become depends on how much pollution we create and how fast we can develop technology to mitigate the effects. Global average temperatures could rise by between 2C and 5C by the middle of the century, leading to animal and plant migrations, rising sea levels and extreme weather events. Developed nations may produce the technology to mitigate the worst effects, but this will be more difficult in developing countries. The sort of sea barriers being developed for the Netherlands, for instance, would be too costly for countries such as Bangladesh, "suggesting the possibility of a massive, chaotic migration of urban populations away from coastal floodplains", the report says. The process of identifying and cataloguing all of the many millions of plants and animals of Earth will continue. The final book of life may even be completed within the next 50 years. To date, between 1.4 million and 1.8 million species have been recorded but there could be as many as 100 million species on Earth.

Scientists will continue to produce more sophisticated computer models of the Earth's climate system and weather forecasting will improve as data collection becomes more sophisticated.

Robotics

A robot that walks like a man will be one of the biggest developments in cybernetics, although mimicking the ability to wield a hammer and pen with the same hand will be even more difficult.

But there is no reason why a robot needs to maintain a definite shape. It can be an assembly of components that reconfigure themselves to suit the task in hand - walking on land, swimming like a fish in water or even flying.

In the more distant future, it may be possible to produce swarms of tiny robots that exhibit the same kind of "swarm intelligence" that makes ants forage more intelligently. "Swarm robotics might provide a better way of monitoring remote environments on earth and on other planets than does a single complex device," the insight says.

Computer power will become more embedded in everyday objects. We already accept that a device in our car can use satellite information to update our position in real time.

Space

The United States has already declared its interest in returning to the Moon, but this time to set up a permanently manned lunar base. Mineral mining and astronomy are just two of the activities that could be carried out.

A lunar base by 2020 could be used as a staging post for a far more ambitious attempt to send a manned mission to Mars after 2030. One possibility is to locate sources of Martian water and use it to manufacture the fuel necessary to build a base on the red planet. China remains the unknown quantity in terms of manned space exploration, says the report. It is possible that economic growth and national pride could lead to a new space race, with China competing against the US to send astronauts to the Moon before 2020.

Once on the lunar surface, solar energy could be used to split any water ice found in lunar craters into oxygen and hydrogen - the basic ingredients of rocket fuel. If solar farms on the Moon can be made large enough it may even be possible to beam energy back to Earth in the form of microwaves. "Large solar farms in direct, constant sunlight could beam energy to Earth via large microwave antennas and provide enough energy to power all of Earth by 2050," says the report.

The moon could also be the source of raw materials such as aluminium, titanium, magnesium, silicon, iron and carbon. It also has stores of the isotope helium-3, a necessary ingredient for nuclear fusion - a potential clean source of energy.

Energy

Demand for energy will continue to rise as developing countries become more industrialised. Over the past 15 years, energy consumption increased at about 1.5 per cent per year. Over the next 20 years it is expected to rise by 2 per cent per year, meaning energy consumption would double in 36 years.

Fossil fuels have supplied much of the energy in the past and there is enough oil in the ground to meet demand for well into the coming century. However, at some point it will begin to run out and alternatives must be considered. Wind energy is the fastest growing alternative source of energy in the world but only nuclear and solar power have the potential to dramatically alter the energy supply landscape. This is because both power sources can potentially produce huge amounts of energy.

Conventional nuclear power produced by fission remains controversial. Waste management is still a largely unresolved issues in many countries. Nuclear fusion remains one of the greatest hopes for unlimited supplies of clean energy. "Iter, a $5bn (£2.5bn) experimental reactor, will come online in about a decade, but success is not guaranteed," the report says. Solar power offers the potential to meet most of our energy needs, but it needs to be more cost-competitive.