Editing Haber process (section)

== Economic and environmental aspects ==
{{Further|Ammonia production#Sustainable production}}
{{externalvideo|video1=[https://www.youtube.com/watch?v=U7l8imwtMkY How Earth's Population Exploded Bloomberg Quicktake]}}
[[File:Severnside fertilizer works - geograph.org.uk - 189990.jpg|thumbnail|upright=1.2|left|Severnside fertilizer plant northwest of [[Bristol]], UK]]
When first invented, the Haber process competed against another industrial process, the [[Frank–Caro process|cyanamide process]]. However, the cyanamide process consumed large amounts of electrical power and was more labor-intensive than the Haber process.<ref name="hager" />{{rp|137–143}}

As of 2018, the Haber process produced 230 million tonnes of anhydrous [[ammonia|ammonia per year]].<ref>{{Cite web |title=Ammonia annual production capacity globally 2030 |url=https://www.statista.com/statistics/1065865/ammonia-production-capacity-globally/ |access-date=7 May 2020 |website=Statista |language=en}}</ref> The ammonia is used mainly as a nitrogen [[fertilizers|fertilizer]] as ammonia itself, in the form of [[ammonium nitrate]], and as [[urea]]. The Haber process consumes 3–5% of the world's [[natural gas]] production (around 1–2% of the world's energy supply).<ref name=Smil_2004_Enriching/><ref>{{Cite web |title=International Energy Outlook 2007 |url=http://www.eia.doe.gov/oiaf/ieo/nat_gas.html |website=eia.gov |publisher=U.S. Energy Information Administration}}</ref><ref>Fertilizer statistics. {{Cite web |title=Raw material reserves |url=http://www.fertilizer.org/ifa/statistics/indicators/ind_reserves.asp |url-status=dead |archive-url=https://web.archive.org/web/20080424083111/http://www.fertilizer.org/ifa/statistics/indicators/ind_reserves.asp |archive-date=24 April 2008 |website=www.fertilizer.org |publisher=International Fertilizer Industry Association}}</ref><ref>{{Cite journal |last=Smith |first=Barry E. |date=September 2002 |title=Structure. Nitrogenase reveals its inner secrets |journal=[[Science (journal)|Science]] |volume=297 |issue=5587 |pages=1654–1655 |doi=10.1126/science.1076659 |pmid=12215632 |s2cid=82195088}}</ref> In combination with advances in breeding, herbicides, and pesticides, these fertilizers have helped to increase the productivity of agricultural land:
{{blockquote|With average crop yields remaining at the 1900 level the crop harvest in the year 2000 would have required nearly four times more land and the cultivated area would have claimed nearly half of all ice-free continents, rather than under 15% of the total land area that is required today.<ref name="Smil 2011">{{Cite journal |last=Smil |first=Vaclav |year=2011 |title=Nitrogen cycle and world food production |url=http://www.vaclavsmil.com/wp-content/uploads/docs/smil-article-worldagriculture.pdf |journal=World Agriculture |volume=2 |pages=9–13 |access-date=16 December 2013 |archive-date=21 June 2015 |archive-url=https://web.archive.org/web/20150621000149/http://www.vaclavsmil.com/wp-content/uploads/docs/smil-article-worldagriculture.pdf |url-status=dead }}</ref>|author=Vaclav Smil|title=Nitrogen cycle and world food production|source=Volume 2, pages 9–13}}

The energy-intensity of the process contributes to [[climate change]] and other environmental problems such as the leaching of nitrates into groundwater, rivers, ponds, and lakes; expanding [[dead zone (ecology)|dead zones]] in coastal ocean waters, resulting from recurrent [[eutrophication]]; atmospheric deposition of nitrates and ammonia affecting natural ecosystems; higher emissions of [[nitrous oxide]] (N<sub>2</sub>O), now the third most important greenhouse gas following CO<sub>2</sub> and CH<sub>4</sub>.<ref name="Smil 2011" /> The Haber–Bosch process is one of the largest contributors to a buildup of [[reactive nitrogen]] in the [[biosphere]], causing an anthropogenic disruption to the [[nitrogen cycle]].<ref>{{Cite journal |last1=Kanter |first1=David R. |last2=Bartolini |first2=Fabio |last3=Kugelberg |first3=Susanna |last4=Leip |first4=Adrian |last5=Oenema |first5=Oene |last6=Uwizeye |first6=Aimable |date=2 December 2019 |title=Nitrogen pollution policy beyond the farm |journal=Nature Food |language=en |volume=1 |pages=27–32 |doi=10.1038/s43016-019-0001-5 |issn=2662-1355 |doi-access=free}}</ref>

Since [[nitrogen use efficiency]] is typically less than 50%,<ref name="Oenema 2009">{{Cite journal |last1=Oenema |first1=O. |last2=Witzke |first2=H. P. |last3=Klimont |first3=Z. |last4=Lesschen |first4=J. P. |last5=Velthof |first5=G. L. |year=2009 |title=Integrated assessment of promising measures to decrease nitrogen losses in agriculture in EU-27 |journal=Agriculture, Ecosystems and Environment |volume=133 |issue=3–4 |pages=280–288 |doi=10.1016/j.agee.2009.04.025}}</ref> farm runoff from heavy use of fixed industrial nitrogen disrupts biological habitats.<ref name=Smil_2004_Enriching/><ref name="Howarth 2008">{{Cite journal |last=Howarth |first=R. W. |year=2008 |title=Coastal nitrogen pollution: a review of sources and trends globally and regionally |journal=Harmful Algae |volume=8 |issue=1 |pages=14–20 |doi=10.1016/j.hal.2008.08.015|bibcode=2008HAlga...8...14H }}</ref>

Nearly 50% of the nitrogen found in human tissues originated from the Haber–Bosch process.<ref>{{Cite journal |last=Ritter |first=Steven K. |date=18 August 2008 |title=The Haber–Bosch Reaction: An Early Chemical Impact On Sustainability |url=https://cen.acs.org/articles/86/i33/Haber-Bosch-Reaction-Early-Chemical.html |journal=Chemical & Engineering News |volume=86 |issue=33}}</ref> Thus, the Haber process serves as the "detonator of the [[Human overpopulation|population explosion]]", enabling the [[global population]] to increase from 1.6 billion in 1900 to 7.7 billion by November 2018.<ref name="Smil 1999">{{Cite journal |last=Smil |first=Vaclav |year=1999 |title=Detonator of the population explosion |url=http://www.vaclavsmil.com/wp-content/uploads/docs/smil-article-1999-nature7.pdf |journal=Nature |volume=400 |issue=6743 |page=415 |bibcode=1999Natur.400..415S |doi=10.1038/22672 |s2cid=4301828 |access-date=16 December 2013 |archive-date=22 January 2021 |archive-url=https://web.archive.org/web/20210122190517/http://vaclavsmil.com/wp-content/uploads/docs/smil-article-1999-nature7.pdf |url-status=dead }}</ref>

[[Regenerative fuel cell|Reverse fuel cell]]<ref>{{cite web | url=https://www.science.org/content/article/ammonia-renewable-fuel-made-sun-air-and-water-could-power-globe-without-carbon | title=Ammonia—a renewable fuel made from sun, air, and water—could power the globe without carbon }}</ref> technology converts electric energy, water and nitrogen into ammonia without a separate [[hydrogen electrolysis]] process.<ref>{{Cite web |last=Blain |first=Loz |date=2021-09-03 |title=Green ammonia: The rocky pathway to a new clean fuel |url=https://newatlas.com/energy/green-ammonia-primer-clean-fuel/ |access-date=2023-03-23 |website=New Atlas |language=en-US}}</ref>

The use of synthetic nitrogen fertilisers reduces the incentive for farmers to use more sustainable [[crop rotation]]s which include [[legume]]s for their natural nitrogen-fixing ability.