No, more CO₂ won't help us grow more food

Contrary to what you might think, more carbon dioxide in the atmosphere is actually bad news for growing food. In this video I talk about why more CO2 means a warmer planet, a drier planet, and less food. But more than that, food that actually contains fewer nutrients...

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Edited by Luke Negus

Video essay about the effects of climate change on agriculture, how climate change will hurt food production, including how climate change will make food less nutritious. More CO2 means more photosynthesis, but more CO2 also means a warmer planet, which means less food, and food lacking in protein. In this video - similar to videos from SciShow, Crash Course, ClimateTown, Our Changing Climate, Veritasium, and Smarter Every Day - I talk about how global warming will impact how much food we can grow.

Huge thanks to my supporters on Patreon: Jimmy Lee, Simon Stelling, Gabriele Siino, Bjorn Bakker, Ieuan Williams, Candace H, Tom Malcolm, Marcus Bosshard, Andrew Knop, Shab Kumar, Brady Johnston, Liat Khitman, Jesper Norsted, Kent & Krista Halloran, Rapssack, Kevin O'Connor, Timo Kerremans, Thines Ganeshamoorthy, Ashley Wilkins, Michael Parmenter, Samuel Baumgartner, Dan Sherman, ST0RMW1NG 1, Adrian Sand, Morten Engsvang, Josh Schiager, Farsight101, K.L, poundedjam, fourthdwarf, Daan Sneep, Felix Freiberger, Chris Field, Robert Connell, ChemMentat, Kolbrandr, , Sebastain Graf, Dan Nelson, Shane O'Brien, Alex, Fujia Li, Will Tolley, Cody VanZandt, Jesper Koed, Jonathan Craske, Albrecht Striffler, Igor Francetic, Jack Troup, SexyCaveman , Sean Richards, Kedar , Omar Miranda, Alastair Fortune, bitreign33 , Mat Allen, Anne Smith, Rafaela Corrêa Pereira, Colin J. Brown, Princess Andromeda, Mach_D, BenDent, Thusto , Andy Hartley, Lachlan Woods, Dan Hanvey, Simon Donkers, Kodzo , James Bridges, Liam , Wendover Productions, Kendra Johnson.

[kingofthend]

As a plant biologist, thank you for this video. People who make this point know litterally only one thing about plants and have no idea of all the other factors in play here. It's the most undercomplex argument one can make.

[debbiehenri]

Very interesting. I've been arguing with people that extra CO2 'won't' provide more food for years - and it's amazing how stubborn people with this belief can be.
For my part - a gardener - one of the most troubling aspects is the fact that extra CO2 will make plants lusher, growing faster and taller.
Unfortunately, this lusher growth makes them more susceptible to damage in extreme weather: they dry up faster in droughts, they break and wither more easily in high winds, they can be more easily battered by heavy rains.
Even worse, all those lusher and softer leaves make them much more prone to pest and disease. Insect attacks are featuring 'more frequently' in the news over the past few years - locusts, for instance - something we in the West seldom heard about before.

On a personal note, I've noticed the recent emergence of several plant diseases and the massive increase in a particular kind of weevil affecting my garden.
The weevil used to stick to wild raspberries as its host plant, feeding on it all the summer. So it never used to be a problem in the past. However, it's now including several other valuable fruit-producing trees and shrubs in the garden, species which it never bothered last year.
I spend hours picking them off by hand - as I don't want to use chemical sprays. However, farmers won't do that. They'll spray crops with even more chemical pesticides, which requires more industrial processes to produce, producing much more CO2 in the making.
How many more times have we got to learn that all chemical sprays do have an eventual effect on the human body?

[bengrean]

The world would be a better place if we had politicians that are actually informed about the topics they reside over. Botany being a key topic

[lordgigenshtain]

as an agricultural technician i am grateful you made a video about agriculture Simon.
in my career its just prevention and adapting agriculture.
also fun fact at 40-45C chlorophyll annihilates due to heat.

[RustyWalker]

Plants close their stomata when its warmer to prevent water loss so there isn't a straightforward relationship between increasing CO2 and increasing plant growth. Add that fact about total nutrient and energy availability decreasing as plants produce more sugar. That impacts how many we need to be healthy, but also being eaten by pests, who also need more of them to survive.
Besides droughts, severe weather can wipe out food crops very quickly.
Folate deficiency can increase the risk of miscarriages.

[enag]

As someone who used to farm way up north, specifically in the tiny north-western dot in Canada on the wheat production map, I'm happy to see it addressed that just moving north isn't a simple solution. While we did have the soil required, the droughts in large forested areas nearby have been causing fires and the reduced sunlight from the smoke blowing over has lost the area at least 1 week of growth each year. This put a lot more pressure on our already short growing season of mid May to mid October and farmers were regularly not finishing harvests in time. Those that were finishing often were taking crops off before they had fully matured resulting in low protein counts. Ultimately my family quit farming in 2019 in part due to the weather related changes causing constant strain.

[bazoo]

So, in short: more CO2 does mean more productive photosynthesis _under ideal conditions_ but the problem is that virtually every other factor influencing yields will change for the worse. Not to mention decreased nutritious value of fast photosynthesizing plants.
In slow changing systems like biocenoses, the best change is usually no change.

[funky]

Its so frustrating, most of this has been known for ages but people just wont accept it and will continue to plug their pollution machienes in. Its so painful how slow the change is happening because of money.

[lucas]

props for comparing numbers properly: 230 million -> 8000 million, using the same multiple (million), instead of switching to billion. Right at the beginning 00:10

[idraote]

Loved this video: the repercussions of global warming you speak about are less immediately evident to the layman and it's good that science communicators finally begin talking about it.

[elliottprats]

The amount of farmland being used to grow crops not for human consumption is a bigger issue. I worked in Iowa (Sept-Dec19’) and was shocked that ALL the corn grown south of I-80 wasn’t edible and was grow for either animal feed or ethanol. If we can waste that much land to grow non edible corn then food shortages must not be an issue, and if it is its mostly a self induced problem

[namenloss]

lower nutrition means physically weaker yes, but more importantly: intellectually stunted.
We can make up for "physically weaker" with modern means, but not intellectually stunted.

[MiguelGarcia-xxwe]

Thank you for this video. Food getting less and less nutritious will definitely be a huge problem in the next decades.

Could you please do a video on the impact that the health of soil has on its ability to store CO2?

[lordrindfleisch]

I saw this brilliant comment in the comment section of a PragerU video. "Life has existed with 10 times higher CO2 concentration in the atmosphere". Well yes mister Conservative, but not current life and certainly not humans.




And you are correct Simon, the Last Jedi sucks

[davidhilderman]

It is helping us grow more food. Lots more. It is the reason that greenhouses PAY for CO2 to increase levels to 1000 ppm. It is one of the reasons that crop productivity records are being broken every subsequent year. Dems da facts man!

[наш_путь]

I study organic vegetable production and regarding crops being less nutrient dense, in our course of soil fertility we studied how cultivated soil around the world having every year less organic matter because of practices like tilling and keeping the soil barren, isn't able to provide nutrients in the correct amounts. This is not only caused by the decrease of soil organic matter but also by the decrease of the soil biota which is the mediator that plants use to absorb nutrients. But it was very interesting to discover a new interpretation of the problem

[dson]

Thankyou for this video. Have found lately alot of people spruiking the "greening" of the planet thing, and this is a perfect response.

[davidbarry]

7:27 Zinc deficiency is also linked to lower male fertility. Increasing grain content in diets and decreasing zinc content in diets are part of the pattern of declining male fertility, although probably not the only factor.

[Gigano]

Terrifying really, but also good to know these effects are avoidable. Thanks for this one!

[stephenjacks]

Except polar temps rise faster than equator, and the 4°C polar temp rise is melting permafrost releasing more CO2 and Methane than humans produce. Even at zero human CO2, we have pushed Earth's Carbon cycle beyond Earth's ability to correct it if we stop polluting.