Agronomy Library > CO2 & GHGs

HOLOS Farm Greenhouse Gas Calculator
Author: Peter Gamache
Date Created: January 21, 2009
Last Reviewed:
For more information on Holos, email Holos@agr.gc.ca. The program is available for download from AAFC. If you would like to participate in RTL's evaluation of the program contact an RTL agronomist. Holos is a whole-farm modelling software program that estimates greenhouse gas (GHG) emissions based on information entered for individual farms. The main purpose of Holos is to envision and test possible ways of reducing GHG emissions from farms. Holos is the culmination of extensive, collaborative study of greenhouse gas emissions from Canadian farms. Much of this research was conducted by Agriculture and Agri-Food Canada scientists in the Model Farm research program. Holos has several unique features. One of these is the use of ‘scenarios’ – common packages of Canadian farm management practices. The user selects scenarios that best describe his/her farm and then adds detail to the extent desired. This makes Holos easy to use, while still allowing flexibility for more intensive analyses. Using a gaming approach, Holos allows users to contemplate possible options that might reduce emissions, and to estimate how those options affect whole-farm emissions. Holos is intended to look into the future, to envision hypothetical scenarios, and look for those practices that best reduce emissions at a specific site before they are implemented. Holos, therefore, is designed primarily as an exploratory tool, rather than as an accounting or inventory tool. It is intended to look into the future and ask ‘what if?’, rather than looking at the past and asking ‘what were my emissions?’ Holos also provides a set of possible mitigation options unique to each farm and lets users explore the impact of these options. Algorithms used in the model are generally based on the Intergovernmental Panel on Climate Change methods, but have been modified for Canadian conditions. The approach of Holos has been to emphasize the interaction of various components on the farm, rather than use exceedingly complex sub-routines of individual facets. Holos focuses specifically on those practices and conditions that might conceivably have significant mitigative effect. The level of detail is also dictated by the amount of supportive scientific information available. Holos estimates carbon dioxide, nitrous oxide and methane emissions from enteric fermentation and manure management, cropping systems and energy use. Carbon storage and loss from lineal tree plantings and changes in land use and management are also estimated resulting in a whole-farm GHG estimate. The estimate is based on a yearly time-step and results are provided as reports or comparative charts.