We're trying to modify photosynthesis to produce hydrogen directly from sunlight.

And for that reason, you do not have photosynthesis in the deep sea.

This is similar to having the Sun shining on the Earth, driving photosynthesis, driving the ecosystem.

There's stromatolites down there the first living things to capture photosynthesis and it's the only place they still occur today.

Photosynthesis is modulated by oxygen, and we have an oxygen insensitive hydrogenase that we think will totally change this process.

And very rapidly, they became multi cellular, they could replicate, they could use photosynthesis as a way of getting their energy source.

But down there, there is no sun, there is no photosynthesis it's chemosynthetic environment down there driving it, and it's all so ephemeral.

And with the absence of photosynthesis you have no plant life, and as a result, you have very little animal life living in this underworld.

And before the discovery of these vents, all life on Earth, the key to life on Earth, was believed to be the sun and photosynthesis.

Their bodies had been totally taken over by another organism, a bacterium, that had figured out how to replicate photosynthesis in the dark, through a process we now call chemosynthesis.

The production cycle of ethanol includes the photosynthesis process that allows the sugar cane to absorb the same amount of carbon dioxide as is released in the burning of alcohol and bagasse.

And that will happen, paradoxically everything you hear about global warming when we hit CO2 down to 10 parts per million, we are no longer going to have to have plants that are allowed to have any photosynthesis, and there go animals.

And basically, our challenge is to optimize the benefits and mitigate the risks of living on a planet that's driven by only two processes, two sources of energy, one of which is solar, that drives the winds, the waves, the clouds, the storms and photosynthesis.

At the extreme opposite end of the size scale, the class of marine bacteria, the Prochlorococci that will be on the final exam although discovered only in 1988, are now recognized as likely the most abundant organisms on Earth, and moreover, responsible for a large part of the photosynthesis that occurs in the ocean.

Confronting the growing challenge means that humanity can no longer afford to ignore the inexhaustible resource found in the organic material that the sun provides each day through photosynthesis. Solar energy enables plants to absorb carbon gas and thereby produce not only oxygen, but also matter that the animal kingdom uses for food and that our machines can use for energy.

And there are also some societal reasons why we might want people to understand what it is that's happening in photosynthesis. For example, one half of the carbon equation is how much we emit, and the other half of the carbon equation, as I'm very conscious as a trustee of Kew, is how much things soak up, and they soak up carbon dioxide out of the atmosphere.