Food companies like Walmart have become more active in the environmental impact of agricultural practices. "On Monday, Walmart held its Global Sustainability Event at its Home Office in Bentonville, Arkansas. The webcast of this event was held online.This seminal event focused on food sustainability, and Walmart’s extensive efforts to manage its supply chain. Many regard this as a promising approach to attaining sustainability, through corporate initiatives rather than government policies. Walmart, the world’s largest employer with revenues equivalent to the GDP of Belgium, is taking advantage of its unique place in the global economy to achieve sustainability goals. Walmart estimates that about 45% of its supply-chain greenhouse gas impact is associated with nitrous oxide emissions from nitrogen fertilizer use.