Forwards or Backwards

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The Invention That Turned Air Into Food

Published · 22 min

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Air is 78% nitrogen, yet for most of history crops starved for it. This video follows how two German chemists learned to pull that nitrogen out of the sky, and what it has cost since.

In September 1898 Sir William Crookes warned that 'England and all civilised nations stand in deadly peril of not having enough to eat', as the guano and Chilean nitrate that fed Europe's farms ran down. On 2 July 1909 Fritz Haber showed BASF a tabletop machine making ammonia from nitrogen and hydrogen. Carl Bosch and Alwin Mittasch turned it into industry: Oppau came on stream in September 1913, Leuna followed in 1917.

The same ammonia made explosives, and Haber organised Germany's gas attacks, including the chlorine attack near Ypres on 22 April 1915. Then the Nobel Prizes of 1918 and 1931, the Oppau explosion of 21 September 1921 that killed more than 500 people, and Haber's resignation in 1933 and death in Basel in 1934.

Today: how a modern plant works; Borlaug's wheat and the estimate that nitrogen fertiliser feeds about half of humanity (Erisman et al., 2008); about 450 million tonnes of CO2 a year (IEA); the Gulf of Mexico dead zone (NOAA, 2025 and 2026); the 2022 gas shock and the 2026 shutdown of shipping through the Strait of Hormuz (World Bank, WTO); green ammonia at NEOM, its cost gap (AGBI, June 2026) and the EU's carbon border levy, charged from 1 January 2026.

No figure appears without its date and source.

Educational documentary. Not financial or investment advice.

In these topics

Tags

  • haber-bosch process
  • fritz haber
  • carl bosch
  • nitrogen fixation
  • ammonia
  • fertilizer
  • fertiliser
  • history of chemistry
  • green revolution
  • norman borlaug
  • oppau explosion
  • chemical warfare history
  • strait of hormuz
  • fertilizer prices 2026
  • urea

Chapters

  1. The nitrogen paradox
  2. The wheat problem
  3. Haber's tabletop reactor
  4. Bosch scales it up
  5. Fertiliser and explosives
  6. Prizes, disaster and exile
  7. Inside a modern plant
  8. Feeding half the world
  9. The hidden costs
  10. A chokepoint for food
  11. Greening the process
  12. Forwards or backwards?

More from Forwards or Backwards on YouTube

Sources and credits

Original narration, artwork, score and editing assembled locally for Forwards or Backwards. No third-party footage, music or imagery.

  • Narration: Kokoro-82M bf_emma, British English.
  • Imagery: generated locally, 12 environments, 12 matched states.
  • Score: original procedural pad, ducked under the narration.

Primary sources

  • NASA NSSDC, 'Earth Fact Sheet' (nssdc.gsfc.nasa.gov) - 78.08% nitrogen, 20.95% oxygen by volume, dry air.
  • Sir William Crookes, 'The Wheat Problem', based on the presidential address to the British Association at Bristol in 1898 (archive.org full text) - both quotations; The Spectator, 10 September 1898 - date of the address.
  • Wikipedia, 'History of Peru (1845-1866)' (Guano Era 1845-1866) and 'War of the Pacific' (1879; nitrate taxation dispute).
  • NobelPrize.org, Fritz Haber biographical (from Nobel Lectures, Chemistry 1901-1921, Elsevier 1966) - 150-200 atmospheres, about 500 C, Bosch and Mittasch, Oppau and Leuna, 'enabled Germany to prolong the First World War', gas attacks, 1918 prize awarded 1919, 1933 resignation, Cambridge, died 29 January 1934 at Basle.
  • NobelPrize.org, Carl Bosch biographical and Nobel Prize in Chemistry 1931 summary - 1908 purchase, iron catalyst, Oppau 1913, Leuna 1917, 1931 prize with Bergius.
  • Science Museum Group, 'Sample of Haber's Synthetic Ammonia, 2 July 1909', object 1952-391/2 - date of the demonstration to BASF.
  • Wikipedia, 'Haber process' - about 125 mL an hour in 1909; exceptionally stable nitrogen; Smil's four-times-the-land estimate. Wikipedia, 'Alwin Mittasch' - systematic catalyst search.
  • BASF, 'Fertilizer out of thin air' (basf.com) - burst reactors, hydrogen embrittlement, soft-iron lining and drilled holes, September 1913, modern reactor >400 C, >150 bar, 15 cm wall.
  • C&EN, '100 Years of Chemical Weapons' - 22 April 1915, 5,730 cylinders, Haber's supervision, Clara Immerwahr.
  • BASF, '100th anniversary of the Oppau explosion' and chronology 1921 - 21 September 1921, 7:32 a.m., over 500 dead, about 2,000 injured, about 4,500 t, more than 20,000 earlier loosening blasts, Bosch's memorial speech.
  • IEA, 'Ammonia Technology Roadmap', Executive Summary, October 2021 - >70% natural gas, China ~85% coal, ~70% to fertilisers, 450 Mt CO2, 2.4 t CO2/t, >70% use-phase, demonstration stage, >110 GW electrolysers, ten 30 MW electrolysers a month.
  • Wikipedia, 'Norman Borlaug'; NobelPrize.org, Nobel Peace Prize 1970 - semi-dwarf wheat, lodging, India and Pakistan.
  • Erisman et al., 'How a century of ammonia synthesis changed the world', Nature Geoscience, published 28 September 2008; Our World in Data, 'How many people does synthetic fertilizer feed?' - 44% (2000), 48% (2008), 1.65 billion in 1900, more than 8 billion today.
  • NOAA NCCOS, 'Below Average Summer 2025 Dead Zone Measured in Gulf', 31 July 2025 - 4,402 sq mi, five-year average 4,755, goal under 1,900; NOAA NCCOS, 5 August 2026 - 1,332 sq mi, Tropical Storm Bertha, five-year average now 3,745 sq mi, goal under 1,900 by 2035; NOAA Ocean Service, 'What is a dead zone?'.
  • Yara, 'Yara implements further production curtailments in Europe', 25 August 2022 - around 35% European ammonia capacity utilisation.
  • World Bank Data Blog, John Baffes and Kaltrina Temaj, 'Fertilizer prices surge as Strait of Hormuz disruptions tighten supplies', 14 May 2026.
  • WTO Data Blog, 'Fertilizer trade impacted by Strait of Hormuz conflict', 10 July 2026; WTO-AXSMarine Strait of Hormuz Trade Tracker, update of 21 September 2026.
  • Fertilizer Daily, 'NEOM green hydrogen complex finishes $8.4 billion construction', 25 August 2026; Air Products Form 10-Q, quarter to 30 June 2026; AGBI, 'Neom green hydrogen project nears completion', 5 February 2026.
  • AGBI, Valentina Pasquali, 'Green ammonia fails to gain from Hormuz fertiliser shock', 15 June 2026.
  • European Commission, Taxation and Customs Union, 'Carbon Border Adjustment Mechanism' - transitional phase 2023-2025, definitive regime from 1 January 2026, fertilisers covered; Commission CBAM Q&A (reported by CLECAT) - certificates on sale from 1 February 2027.
  • Wikipedia, '2026 Strait of Hormuz crisis' (revision of 18 September 2026) - strikes on Iran from 28 February 2026; IRGC warnings to shipping; no formal blockade declared.
  • World Bank Commodity Price Data (Pink Sheet), September 2026 - urea (E. Europe, f.o.b. Middle East) $453.1/t June, $400.0 July, $390.0 August 2026.
  • Air Products Form 8-K, exhibit 99.1 (Q3 FY2026 results, 30 July 2026); World Fertilizer, 4 August 2026 - Yara marketing and distribution agreement for NEOM ammonia.
  • NOT USED: a single count of Mittasch's catalyst trials (sources differ); the claim that NEOM was 'delayed' (no source gives an original start date); the claim that Iran formally declared the strait closed (it did not); Borlaug's seed-shipment year; the Oppau toll as 561 (BASF says over 500).

Figures were not re-pulled within 48 hours of export; re-verify before publication if the film is held.

Not regulated financial advice.