Water-Food-Climate Squeeze: Can we bio-engineer our way out?

Dr. Praveen Kumar, Professor of Civil and Environmental Engineering at the University of Illinois at Urbana-Champaign, gave a talk titled The Water-Food-Climate Squeeze: Can we bio-engineer our way out? He discussed the topic from an physical, biological, and climatological prospective. He focused on a few fundamental problems such as how will we feed people as our global population grows? Also, what changes will occur to plants and crops do under climate change.

We need to increase crop yield, improve water use efficiency, increase albedo (reflectivity), and use the same amount of land for crops. Interestingly Kumar showed that arable land is increasing in developing countries but declining in developed countries, but the ultimate takeaway is that cropland per person is decreasing fast. Fifteen percent of terrestrial land is devoted to agriculture. With water, the more we use in agriculture means there will be less for consumption.

The University of Illinois has conducted a field study growing soy and corn crops at elevated carbon dioxide levels, focusing the talk on the 550 ppm level, a likely concentration in the future. They found that the plants had a clear increase in their temperature and decrease in transpiration, as well as changing the chemistry.

Dr. Kumar then ran a model to try and understand what is causing these changes. It found that plant productivity is heterogeneously distributed vertically, and we may be able to take advantage of this to optimize production. It may be possible to find vertical structures for a whole canopy that will allow increased productivity, reduce water use, increase albedo, and increase photosynthesis, simultaneously. When searching for a solution that could maximize or minimize the key factors, it was found that optimal leaf area index was less than existing, meaning that if we decreased the number of leaves then it would increase the yield. Without making changes to the genetics of the crops this result can have impacts on the amount of food produced.

The results are robust under present and climate change scenarios. The science behind Dr. Kumar's research, as well as many other scientists, is going to help agriculture continue to improve with or without a changing climate. The future of the science is to look at very fine resolutions, on the meter scale via remote sensing techniques such as LiDAR (Light Detection and Ranging), to find the best ways to spatially grow crops with the natural topography. The small-scale depressions and subtleties in topography will have impacts on the hydrology and thus growth of crops differently. To optimize the water use and land use, there will likely be assorted crops planted in a single field based off the topography.