The world has right now, close to a billion cars,
and we might double the number of cars on the planet by 2050.
So that is going to have a big, big footprint
in terms of our demand for resources to move all those vehicles around.
We are pulling up carbon that has been stored underground
and burning it in our automobiles,
and putting all that carbon dioxide in the atmosphere.
If we don't reduce that
we could have changes in the climate that we could never recover from.
This has kicked off people looking at a whole range
of other alternatives to petroleum in your tank.
When we started the ethanol programme in Brazil in 1975,
nobody was talking about reducing emissions,
this was not an issue at that time.
First and most important,
we didn't have money to buy oil any more after the first oil shortage.
We were importers of oil
and today more than 50 percent of all cars
use ethanol instead of gasoline.
Sugar cane to ethanol is an incredibly efficient process.
They extract the sugar from the cane,
the sugar goes into these large fermentation tanks
with yeast that naturally produces ethanol,
they use the rest of the plant to generate heat
to distil the ethanol and turn it into fuel,
not putting excess carbon dioxide in the atmosphere
and you get out about seven times the energy you put into growing the sugar cane.
In the U.S. when we produce ethanol from corn,
for every unit of input of energy we get about the same amount of energy out,
so we're really not gaining anything.
We need a better process,
so the crops that we're looking at are crops like switchgrass.
This is a native grass that grows without a lot of water and on marginal lands,
that we could turn into energy farms,
but that's a really complicated process.
We extract the glucose from the plant,
and then we feed that glucose to a yeast
that we've engineered to produce hydrocarbons,
and the yeast takes in the sugar and gives us this high-energy molecule.
The role of biofuels is quite tricky
and this really boils down to the fact there is only so much arable land
and growing fuel for our gas tanks
is yet another demand on that landscape.
But there are a variety of crops that do not compete directly with food
and finding ways to utilize those types of crops first,
that's very attractive and this equation is really wide open.
Imagine that you could have one process,
that could take in sunlight and carbon dioxide and turn it into fuel,
and imagine if that didn't involve growing anything at all.
Materials chemists like myself want to do artificial photosynthesis
to improve on the process that nature does in real photosynthesis.
All we really need is a light absorber that absorbs sunlight,
we also need a catalyst like iron or nickel.
Ultimately our pieces are going to be contained
in something that is easy to roll out,
or in would come sunlight and water,
you would vent the oxygen to the air
but the bottom would wick out your liquid or gaseous fuel,
that then you could use for our cars and planes and storage.
If you think about how long it's taken for us to build up the petroleum industry,
we can't hope to reverse that overnight.
It's a huge change in our infrastructure
and that means basic research needs to be done,
now and by as many people as possible.
We have a long way to go,
but I am confident that we will get there.