Humanity is facing problems so great that only science can now save us. That was the message given by American biologist Dr Craig Venter in the annual BBC Television Richard Dimbleby Lecture.

Dr Venter is world-renowned for his role in the sequencing of the human genome, where he speeded up the analysis by the development of the technique known as shotgun sequencing. He is now leading research in engineering bacteria to tackle major challenges such as synthesising fuel and medicines.

In the Dimbleby Lecture, he set out the issues starkly. 'Our planet is in crisis, and we need to mobilise all of our intellectual forces to save it.'

He described the rise in temperature produced by carbon dioxide.

'Eleven of the last 12 years rank among the warmest years since 1850. While no one knows for certain the consequences of this continued unchecked warming, some have argued it could result in catastrophic changes, such as the disruption of the Gulf Stream which keeps the UK out of the ice age or even the possibility of the Greenland ice sheet sliding into the Atlantic Ocean. Whether or not these devastating changes occur, we are conducting a dangerous experiment with our planet. We need to stop.'

He warned that the increasing world populations would add to the rise in greenhouse gas levels.

'This means we can expect more climatic change, more ice cap melts, rising sea levels, warmer oceans and therefore greater storms, as well as more droughts and floods, all of which compromise food and fresh water production.'

The only solution, said Dr Venter, will be major scientific breakthrough - the development of 'disruptive' ideas and technologies, ones which overturn the dominant technologies and products in the marketplace.

And key areas where disruptive technologies were likely to develop, he said, were in some of the new fields of biology - synthetic biology, synthetic genomics, and metabolic engineering.

'We and others have been working for the past several years on the ability to go from reading the genetic code to learning how to write it. It is now possible to design in the computer and then chemically make in the laboratory, very large DNA molecules. A few months ago we published a scientific study in the journal Science where we described the ability to take a chromosome from one bacterium and place it into a second bacterial cell. The result was astonishing - the new DNA that we added changed the species completely from the original one into the species defined by the added DNA.'

With this kind of ability, said Dr Venter, major breakthoughs could be made. The DuPont company were now operating a plant using metabolically engineered bacteria to convert sugar into a new polymer for carpets and clothing. Several teams, including his own, were modifying bacteria to make the generation of biofuels. One of his research groups had developed microbial fuel cells using naturally occurring bacteria, which could in this way process human and animal waste to produce electricity and clean water.

'At my company Synthetic Genomics, we have a major program underway in collaboration with BP to see if we can use naturally occurring microbes to metabolise coal into methane which can then be harvested as natural gas. While not a renewable source of carbon, it could provide as much as a 10 fold improvement over mining and burning coal. We also have organisms that can convert CO2 into methane, thereby proviiding a renewable source of fuel.'

In closing, said Dr Venter, humanity was not already on a path toward significant change, but it was still possible to tackle the problem.

'If we apply ourselves I believe we can find ways to create alternatives to burning oil and coal. We need multiple simultaneous approaches to solve this problem, with the goal of net zero carbon emissions to stabilize atmospheric concentrations and ensure our survival. These are massive challenges for each and every one of us. For our children's future and for the future of our planet I hope that we can rise to the challenge.' 

The text of Dr Venter's Richard Dimbleby Lecture can be found on the BBC website.