Facts and figures about fertilizers and climate change
The primary objective of agriculture is to feed the world. It has been estimated that almost half the people on the Earth (around 48%) are currently fed as a result of manufactured nitrogen fertilizer use (Erisman et al. 2008).
Tthe share of total global GHG emissions directly related to the production, distribution and use of fertilizers is between 2 and 3%.
By 2050 it is estimated that agricultural demand will range from 50 to 80% above today’s level of production (Müller 2009, FAO 2006). The expected increase in arable land area is estimated to be much lower, implying a need to further increase land productivity (FAO 2003). Because any reduction in production intensity at one location would need to be compensated by additional production elsewhere, it is imperative to optimize agricultural production per unit of land in order to meet future demand.
According to the agricultural chapter of the Fourth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC), direct agricultural emissions made up 10-12% of total anthropogenic GHG emissions in 2005 (5.1-6.2 Pg CO2-eq) (Smith et al. 2007). GHG emissions from deforestation, mainly in tropical countries, contributed an additional 5.9 Pg CO2-eq per year (with an uncertainty range of ±2.9 Pg CO2-eq), thus equalling or exceeding emissions from all other agricultural sources combined.
Sources of fertilizer related GHG emissions
| Sources | Tg CO2 -eq | % of total global GHG emissionsa |
| Total global GHG emissions (2005) | 50,000 | 100% |
| Bellarby et al. 2008 | ||
| All N, P and K manufacturing by the fertilizer industry (2007)b | 464.8 | 0.93 |
| -- Of which industrial uses | 82.0 | 0.16 |
| -- Of which fertilizers only | 382.8 | 0.77 |
| Calculated using methodology from Kongshaug 1998, Prince's 2007 estimate of the GHG index of each ammonia production process (BAT) and IFA 2008a. | ||
| Fertilizer use in agriculture | 738.1 | 1.48 |
| -- Nitrous oxide (N2O) from soilsc | 604.6 | 1.21 |
| -- CO2 from applied urea | 105.6 | 0.21 |
| -- CO2 from applied ABC | 17.9 | 0.04 |
| -- Farm machineryd | 10 | 0.02 |
| Calculated using Bellarby et al. 2008, Brentrup 2008, methodology from Kongshaug 1998, IFA 2008a and IFADATA consumption statistics for 2006. | ||
| Fertilizer transport and distributione | 37.2 | 0.07 |
| Estimated using IFA 2008a and LCA methodology. | ||
| Total estimated emissions related to the fertilizer life cycle | 1240.1 | 2.48% |
a As global emissions are likely to have been higher in 2006 and 2007, the actual percentages may be slightly lower than shown here. The latest available data have been used for each activity.
b No global benchmark exists for greenhouse gas emissions for any fuel sources except natural gas. We have therefore multiplied the GHG index for BAT coal-based production (Prince 2007) by the industry benchmark for natural gas-based production (IFA 2008b).
c The value for N2O emissions related to fertilizer use is calculated using the IPCC methodology for national emissions inventories (IPCC 2006). The data obtained using this methodology are subject to considerabe uncertainty.
d Only a portion of farm machinery use can be attributed to spreading fertilizers, so we have included one-third of 30, which is the average 3-57 Tg reported by Bellarby et al.
e Emissions related to the transport of raw materials are not included in this table.
Potential GHG emissions reductions through the adoption of Best Practice Technologies in fertilizer production
| Tg CO2-eq/year | % of the sector's current GHG emissions | |
| -- Natural gas-based ammonia production | 27 | 5.8 |
| -- N2O abatement in nitric acid production | 73 | 15.7 |
| -- All other processes | 19 | 4.1 |
| TOTAL | 119 | 25.6 |
| -- BPTs and CCS in coal-based ammonia production* | 100 | -- |
| Source: Calculated using IFA production statistics for 2007, Kongshaug 1998 and IEA 2006. | ||
* This figure for reductions related to coal-based production has not been included in the total because the available information about the current deployment of technologies used in coal-based ammonia production only allows us to make an extremely rough estimate for indicative purposes. No credible benchmark has been established for the coal-based processes.