Throughout the modern age, the world has experienced explosive population growth — a number that will continue to grow larger and faster. Other metrics have consequently seen explosions of their own. Agricultural science and policy have pushed crop yields to all time highs; the amount of energy produced and consumed in the past 70 years nearly doubles that of the previous 11,000 years; and, as a result, humanity has created enough of a footprint from released pollutants and greenhouse-gasses for scientists to consider marking a new geological epoch.
Dr. Steven Chu, a current professor of physics at Stanford University, addressed these evolving trends in a lecture delivered through the University of Wisconsin-Madison’s Physics Department this February. Chu — a partial recipient of the 1997 Nobel Prize in Physics — served as the Secretary of Energy under the Obama administration from 2009 to 2013.
During his time in office, Chu worked to maintain awareness and spur action around how the U.S. energy sector can be and needs to be adapted in the face of a warming global climate. Chu previously called for increased data collection and regulation on the expansion of fossil fuel technology, especially natural gas and fracking.
More recently — as discussed in Chu’s February lecture — he widened his topics of interest. In addition to energy issues, Chu now connects issues such as water availability and agriculture sustainability to the greater movement of reducing humanity’s impact on our climate.
Chu sets the stage by highlighting that a transition to a more sustainable future will not be without its own challenges. Pointing to the decreasing costs in renewable technologies, for instance, Chu cautioned that when including the peripheral needs of renewable technology — such as energy storage, resource acquisition and infrastructure — the overall cost will most likely still need to “reduce by half” before meaningful widespread adoption.
Despite this, Chu referred to several achievable goals that can ease an interim transition. He identified the need to reinvest in nuclear fission to make reactor construction “on budget and on time.” Additionally, he pointed to the role hydrogen can play in decarbonizing the many greenhouse gas-emitting industrial processes in the United States.
While progress in energy production and industrial efficiency are important first steps in fighting climate change, Chu argued decarbonization efforts need to go a lot further. For instance, technologies such as plastic and practices including planned obsolescence and general mismanagement of material are important targets for improvement, according to Chu.
“The goal is to reuse, not recycle,” said Chu.
One of the most unconventional changes Chu argued for at the talk is what he calls a “fourth agricultural revolution.”
Historically, through social structure reworks and scientific enhancements, humanity has made great strides in maximizing agricultural yields. However, these benefits come at a cost.
“We over fertilize,” said Chu. Many nitrogen-based fertilizers release nitrous oxide if they go unused by plants. Nitrous oxide (N2O) is a greenhouse gas three hundred times more potent than carbon dioxide, leading to its emissions having a relatively outsized effect on global warming. Currently, Chu suggests, “we’re lucky” if a plant uses half of its fertilizer and that future fertilizing techniques will need to cut back on this waste.
To improve farming sustainability, Chu pointed to technologies like synthetic biology and carbon capture techniques. Seeding farm plots with nitrogen-fixing bacteria — little microbes that cling to the roots of plants — could drastically reduce emissions and cut back on the total consumption of fertilizer, all while still providing the high agricultural yields a growing population demands, he said.
The fight against climate change must be a concerted one, Chu argued. Many seemingly unrelated sectors need systematic change to reduce and eventually recapture greenhouse gas emissions, Chu noted.
