By Tim Radford
Climate News Network
Renewable energy experts and microbiologists have teamed up to create a super-efficient artificial leaf that uses photosynthesis to produce carbon-neutral
liquid fuels.
S
cientists in the US claim to
have beaten nature at its
own game. They have created a “bionic leaf”
that exploits sunlight to create biomass − and they say their invention
is now 10 times more effective than
an oak or maple leaf.
Two separate laboratories
at Harvard University have cooperated to devise, enhance and
test a system that uses sunlight to
split water molecules and feed the
hydrogen to bacteria that then produce liquid fuels. The next task is to
scale up the experiment to produce
carbon neutral fuels to combat climate change.
“This is a true artificial photosynthesis system,” says Daniel Nocera, a
leading researcher in renewable
energy who is professor of energy
at Harvard. “Before, people were
using photosynthesis for watersplitting, but this is a true A-to-Z
system, and we’ve gone well over
the efficiency of photosynthesis in
nature.”
Photosynthesis was perfected by
the plant world over more than 3
billion years of evolution. It drives
the entire living world and it is the
primary source of all fossil fuels.
Ancient sunshine
Climate change became a problem
only when humans started to ex-
tract ancient sunshine in the form
of coal, oil and natural gas, stored
in the Carboniferous rocks, and put
it back in the atmosphere.
Just as wood fires from felled timber make no difference to the atmosphere’s carbon dioxide levels –
because the same forest that shelters the fallen tree will absorb it
again – so biofuels converted from
surplus maize or sugarcane should,
in theory, make no difference to
global warming.
So the idea of what the Harvard
team call “bionic leaf 2.0” is an attractive one. It could deliver liquid
fuels in convenient form that would
make no difference to the planet’s