This study attempts to quantify the economic and environmental impact of the National Broadband Network (NBN) being deployed in Australia. Three key features underpin the results presented in this paper. First, the economic situation in Australia in the long run without the NBN was compared with the economic situation in Australia with the NBN. Second, nowhere in the analysis was it assumed that there is a benefit in providing broadband access per se. Instead, a range of new services that have well-attested economic benefits were included. Third, the study relies on a wellfounded comparative static computable general equilibrium (CGE) economic model of the Australian economy to assess the effects of the NBN in the short and long run. We find that in a typical shortrun year during the construction of the NBN, economic activities increase predominantly in the construction and related industries. The results suggest no net increase in domestic greenhouse gas (GHG) emissions in the short run. In a typical long-run year post NBN deployment, the continued increase in economic activity results in GHG emissions going up more significantly than during NBN deployment. Achieving a reduction in domestic GHG emissions will require appropriate policy implementation specifically targeting GHG emissions to complement the introduction of ubiquitous broadband in the form of the NBN in Australia. Subject to the cost of domestic abatement policies and purchasing overseas permits, the environmental impact of the NBN in monetary terms can be compensated by economic welfare gains if the expected bandwidth requirements of services included in this study are sufficiently large.