Lewis Ziska

Carbon Dioxide, Climate Change and Agricultural Productivity

Lewis H. Ziska, PhD, Crop Systems and Global Change Laboratory, USDA-ARS.

Email: l.ziska@usda.ars.gov

Anthropogenic needs for energy and food are ongoing drivers for the observed increase in atmospheric carbon dioxide (CO2).  Such increases at the global level are likely to alter agricultural productivity by: (a) supplying additional carbon for photosynthesis and growth; (b) altering biological pest pressures and, (c) imposing climatic extremes, specifically surface temperatures and precipitation.  In this overview I will present data from a number of sources that document the likely negative impacts of climate / CO2 on sustainable agricultural productivity including water resources, temperature, monocultures and pests (e.g. weeds).  However, I will also address potential opportunities associated with climate change and CO2, particularly the work on intra-specific variability in regard to adaptation of crop lines to rising carbon dioxide and temperature, including recent efforts to characterize the adaptation of wild crop lines to climatic extremes; the utility of diverse agronomic practices to minimize climatic extremes, and the increasing role of education and communication.  Overall, while challenges related to climate, CO2 and food security are clear and immediate, there is sufficient information available to begin a long-term redress of these challenges to global food security.