Ammonia currently enjoys renewed interest as a potential vehicle fuel or hydrogen carrier. Since it does not contain carbon, its combustion in air emits no carbon dioxide, although oxides of nitrogen are generally higher than other hydrocarbon fuels. It is considered a hazardous material that poses a serious health and safety risk if handled improperly. Ammonia (NH3) is possibly the most common synthesized chemical in the world, mostly for agricultural use as nitrogen fertilizer or as a precursor to other fertilizers such as ammonium nitrate. Its role in agricultural productivity cannot be underestimated. Agriculture in most industrialized countries relies on ammonia to replace depleted soil nitrogen after several seasons of monocrop cultivation. It is commonly believed that much of the world population would starve without it. Approximately 95% of all hydrogen is produced from natural gas or coal solely for ammonia production, and this hydrogen production is believed to account for 2% of all anthropogenic greenhouse emissions. Like hydrogen, ammonia can be burned directly in an internal combustion engine. It can also be used for onboard hydrogen generation, in which it is catalytically reformed at high temperature into hydrogen and nitrogen. Ammonia is generally a poor fuel for IC engine fuels, with major environmental impacts and hazardous handling issues.