Humans have only just begun dabbling with solar power, but other organisms have been converting sunlight into energy for more than three billion years. In fact, we’re only just beginning to understand how they do it.
So it is for his groundbreaking work in helping us humans understand the process of photosynthesis that Graham Farquhar has today received this year’s Prime Minister’s Prize for Science.
Graham is Distinguished Professor of the Australian National University’s Research School of Biology and Chief Investigator of the Australian Research Council’s Centre of Excellence for Translational Photosynthesis.
When he started out studying photosynthesis, Graham found that researchers from disparate fields within biology and biochemistry all had their own narrow views on how photosynthesis worked. But few were able to link together all the pieces of this complex puzzle.
So Graham brought his experience as a biophysicist to the problem and worked to describe how the components of photosynthesis connect in a mathematical way. He was particularly interested in how the process operates under different environmental conditions, such as when water is scarce. This is useful, because if we can understand this, then we can breed plants that can better withstand drought.
“All these things start with equations,” he says. “They’re just a rough approximation of reality, but in this case they were good enough to be able to point us in the right direction to select plants for water use efficiency.”
Graham’s models have also revealed some very interesting things about how plants function, such as how they carefully balance the trade-off between growing more and losing more water.
He also found that plants can actually affect the weather itself.
“About 70% of water that falls on land is evaporated, most of that through vegetation,“ he says. “That evaporation cools the leaves, and over a sufficient area, that affects the local weather and climate.”
He is also interested in how plants are responding to climate change. In fact, he suggests that our carbon emissions have already changed agriculture.
“My reckoning is that if we could get rid of all the anthropogenic carbon dioxide emitted since the industrial revolution, then agricultural productivity would drop by 15%,” he says.