The role of non-CO2 greenhouse gases in cost-effective strategies to reduce pollution by dairy cattle in the Czech Republic

Agriculture is an important source of greenhouse gases, including methane (CH4) and nitrous oxide (N2O). In addition, it is a source of compounds contributing to other environmental problems such as acidification, terrestrial and aquatic eutrophication, tropospheric ozone formation, and human health problems. These compounds include, for instance, ammonia (NH3), nitrogen oxides (NOx), and particulate matter (PM) volatile organic compounds or nitrate ( NO-3). In this article, we address the question how we can reduce the overall environmental impact (OEI) of agriculture at least costs, and what the role of non-CO2 greenhouse gases in these optimal solutions is. We present results of the DAIRY model, an optimization model for the Czech dairy production sector. The model distinguishes between nine study regions defined according environmental and agriculture characteristics and calculates emissions, their potential impact and OEI at regional and national level. We show that in cost-effective scenarios the model tends to select measures to reduce emissions contributing to climate change and aquatic eutrophication first. This is in contrast with current policies in the Czech Republic, which is aiming at reduction of emissions causing acidification and eutrophication. We also show that reducing greenhouse gas emissions plays a modest role in optimal strategies to reduce the OEI of dairy production