{"id":432082,"date":"2026-03-18T19:21:57","date_gmt":"2026-03-18T18:21:57","guid":{"rendered":"https:\/\/climatescience.press\/?p=432082"},"modified":"2026-03-18T19:22:00","modified_gmt":"2026-03-18T18:22:00","slug":"ever-wrong-ehrlichs-greatest-hits-er-misses","status":"publish","type":"post","link":"https:\/\/climatescience.press\/?p=432082","title":{"rendered":"\u2018Ever-wrong Ehrlich\u2019s\u2019 Greatest Hits (er, misses)"},"content":{"rendered":"
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From Watts Up With That?<\/a><\/p>\n\n\n\n

By Dave Burton with a postscript by Anthony Watts<\/strong><\/p>\n\n\n\n

Biologist Paul Ehrlich died on Friday, March 13, 2026, at the age of 93.<\/p>\n\n\n\n

His famous 1968 book, \u201cThe Population Bomb,\u201d changed the world. He famously predicted that human \u201coverpopulation\u201d would soon outstrip food supplies, leading to catastrophic famines, and societal collapse. He predicted that hundreds of millions of people would starve to death in the 1970s and 1980s, that India would be unable to feed its population by 1980, and that major countries like England would no longer exist by the year 2000.<\/p>\n\n\n\n

The New York Times tactfully wrote<\/a> that, \u201chis predictions proved premature.\u201d<\/em><\/p>\n\n\n\n

When Ehrlich wrote his book, in 1968, the world\u2019s human population was between 3.5 and 3.6 billion people. Today it is over 8 billion. Yet famine deaths, which were common when Ehrlich wrote his book, have become rare, as population and CO2 levels have risen:<\/p>\n\n\n\n

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It\u2019s mainly because crop yields have risen even faster than population:<\/p>\n\n\n

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Crop Yields – Our World in Data<\/a><\/figcaption><\/figure>\n<\/div>\n\n\n

Several factors have contributed to that (surprising to Ehrlich!) improvement, but three of the most important factors are all thanks to fossil fuels:<\/p>\n\n\n\n

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  1. One important way that fossil fuels contribute to rising crop yields and save us from famines is by \u201cCO2 fertilization<\/strong>.\u201d CO2 emissions slowly raise the CO2 level in the atmosphere, which makes plants healthier, faster growing, and more productive.<\/li>\n<\/ol>\n\n\n\n

    The large benefits of elevated CO2 for crops have been known to science (though perhaps not to Ehrlich) for more than a century. The benefits are so dramatic that in 1920 Scientific American called anthropogenic CO2 emissions \u201cthe precious air fertilizer.\u201d<\/em><\/p>\n\n\n\n

    Gradenwitz A. (1920)<\/a>. \u201cCarbonic Acid Gas to Fertilize the Air.\u201d Scientific American,<\/em> Nov 27, 1920. doi:10.1038\/scientificamerican11271920-549<\/p>\n\n\n\n

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    2.<\/strong> Elevated CO2 not only benefits crops by CO2 fertilization, it also improves water use efficiency & drought resilience<\/strong> of crops, through reduced stomatal conductance. Here are some papers about it:<\/p>\n\n\n\n

    De Souza, A.P. et al.<\/em> (2015). \u201cChanges in Whole-Plant Metabolism during the Grain-Filling Stage in Sorghum Grown under Elevated CO2 and Drought.\u201d Plant Physiology,<\/em> 169(3), Nov 2015, 1755\u20131765. https:\/\/doi.org\/10.1104\/pp.15.01054<\/a><\/p>\n\n\n\n

    Fitzgerald GJ, et al.<\/em> (2016). \u201cElevated atmospheric [CO2] can dramatically increase wheat yields in semi-arid environments and buffer against heat waves.\u201d Glob Chang Biol.<\/em> 22(6), 2269-84. https:\/\/doi.org\/10.1111\/gcb.13263<\/a><\/p>\n\n\n\n

    Chun, J.A. et al.<\/em> (2021). \u201cEffect of elevated carbon dioxide and water stress on gas exchange and water use efficiency in corn.\u201d Agricultural and Forest Meteorology,<\/em> 151(3), 378\u2013384, ISSN 0168-1923. https:\/\/doi.org\/10.1016\/j.agrformet.2010.11.015<\/a><\/p>\n\n\n\n

    EXCERPT: \u201cThere have been many studies on the interaction of CO2 and water on plant growth. Under elevated CO2, less water is used to produce each unit of dry matter by reducing stomatal conductance.\u201d<\/em><\/p>\n\n\n\n

    Note that wheat is a C3 crop, but corn and sorghum are C4 crops<\/a>. Both benefit, but C3 crops benefit more. (Most crops are C3.)<\/p>\n\n\n\n

    Trees are also C3 plants:<\/p>\n\n\n\n

    Idso & Kimball (1994)<\/a>. \u201cEffects of atmospheric CO2 enrichment on biomass accumulation and distribution in Eldarica pine trees.\u201d Journal of experimental botany.<\/em> 1994 Nov., v. 45, no. 280 p.1669-1672. (preprint here<\/a>)<\/p>\n\n\n\n

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    Eldarica_pine_trees_vs_CO2.jpg (1074\u00d7646)<\/a><\/figcaption><\/figure>\n\n\n\n

    3.<\/strong> The third way that fossil fuels save us from famines is by enabling the creation of synthetic nitrogen fertilizer, from fossil fuels (mostly natural gas), using the Nobel-winning<\/a> Haber-Bosch process.<\/p>\n\n\n\n

    Manure, compost, and bird & bat guano can also provide fertilizer, but not nearly enough to feed the world. The Haber-Bosch process eliminated that agricultural bottleneck<\/a>.<\/p>\n\n\n\n

    As a bonus, when nitrogen fertilizer is made from natural gas, the carbon is released as CO2, just as it is when the natural gas is burned for heat.<\/p>\n\n\n\n

    There are other factors which have also helped, but it\u2019s mostly thanks to fossil fuels that you can afford to buy food for your family.<\/p>\n\n\n\n

    4. <\/strong>Agricultural mechanization is one of the other things which have helped\u2026 but that\u2019s also powered by fossil fuels<\/p>\n\n\n\n

    5. <\/strong>Pesticides have also helped a lot\u2026 but they\u2019re also mostly made from petrochemicals.<\/p>\n\n\n\n

    6. <\/strong>Improved hybrid & GMO crops have also helped a lot.<\/p>\n\n\n\n

    The people who are crusading against fossil fuels might not realize it, but they are campaigning for a world in which parents watch their children starve.<\/p>\n\n\n\n

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    To understand a contentious, politicized issue like climate change, you need balanced information. I\u2019m here to help:<\/p>\n\n\n\n

    Learn More About Climate Change – resources<\/a><\/p>\n\n\n\n

    That\u2019s my resource list with:<\/p>\n\n\n\n

    \u25cf accurate introductory climatology info
    \u25cf in-depth science BOTH from scientists who are worried about man-made climate change, and from scientists who are not.
    \u25cf links to balanced debates between experts on BOTH sides of the issue
    \u25cf info about climate impacts
    \u25cf links to the best blogs on BOTH sides (and WUWT is top of the list, of course)<\/p>\n\n\n\n

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    Postscript by Anthony Watts<\/strong><\/h3>\n\n\n\n

    Where to start? It is such a target rich environment.<\/p>\n\n\n\n

    Some WUWT posts worth revisiting:<\/em><\/strong><\/p>\n\n\n\n

    Friday Funny: Paul Ehrlich Discredits the Peer Review Process<\/a><\/strong><\/p>\n\n\n\n

    That post was in response to this (because peer review is perfect, ya know)\u2026the hubris is off-the-scale.<\/p>\n\n\n\n

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    60 Minutes extinction story has brought the usual right-wing out in force. If I'm always wrong so is science, since my work is always peer-reviewed, including the POPULATION BOMB and I've gotten virtually every scientific honor. Sure I've made some mistakes, but no basic ones<\/p>— Paul R. Ehrlich (@PaulREhrlich) January 3, 2023<\/a><\/blockquote>