Study finds growing evidence of global warming threat to future food supplies

Jan 15, 2013

(Phys.org)—Increasingly hot summer weather could cause a fall in crop yields over the next two decades unless farming techniques are improved more quickly, scientists at the University have found.

are having an increasingly damaging effect on maize (sweetcorn) in France – the largest supplier of the crop to the UK – which may explain a recent slowdown in the trend towards higher yields, according to researchers at the Universities of Leeds, Reading and Exeter.

Improvements in agricultural technology, such as fertilisers and new , will need to increase yields by up to 12% by the 2020s to be confident about offsetting future decreases in yield from .

However, the current rate of improvement, driven by , is not quick enough to meet such a high target, says research published today in the journal .

Professor Andrew Challinor, from the University of Leeds' School of Eearth & Environment, said: "Feeding a growing population as climate changes is a major challenge, especially since the land available for agricultural expansion is limited. Supplies of the major food crops could be at risk unless we plan for future climates."

Dr Ed Hawkins, from the National Centre for Atmospheric Science (NCAS) at the University of Reading, said:

"Our research rings alarm bells for future food security. Over the last 50 years, developments in agriculture, such as fertilisers and irrigation, have increased yields of the world's staple foods, but we're starting to see a slowdown in yield increases. Our research into maize suggests the increasing frequency of hot days across the world might explain some of this slowdown.

"We expect hot days to become more frequent still, and our work on maize suggests that current advances in agriculture are too slow to offset the expected damage to crops from heat stress in the future."

The study shows that over the last 50 years, yields of maize in France have become less sensitive to variations in the amount of rain over the summer and relatively more sensitive to temperature. This is likely due to increased irrigation and hence reduced dependence on natural rainfall. This means that temperature may be more significant than rainfall for future yields.

The number of days with temperatures over 32 degrees C has more than doubled in some parts of France over the last 50 years. Many other land areas show similar increases. By the 2020s, temperatures over 32 degrees C could occur over large areas of France where previously they were uncommon. Without agricultural development, this increase in hot days could decrease yields of French maize by more than 10% relative to current yield, the research found.

Explore further: Air quality in San Joaquin Valley improving according to study

More information: The paper 'Increasing influence of heat stress on French maize yields from the 1960s to the 2030s' has been published in Global Change Biology. DOI: 10.1111/gcb.12069 http://dx.doi.org/10.1111/gcb.12069

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The Alchemist
1 / 5 (7) Jan 15, 2013
Looks like we need to climate control those farms: transparent roof, control runoff, recycle water, is there a down side?
antialias_physorg
4 / 5 (8) Jan 15, 2013
is there a down side?

A missing sense of realism? Have you ever been out in a field? Have you ever seen how absolutely huge the fields are that feed a populace?
The Alchemist
1 / 5 (5) Jan 15, 2013
LOLOLOLOLOL- a little bit of sarcasm.
But let me ask you a question, "when was the last time you built the pyramids?"
Yes, it would be a huge endeavor, and yes, it probably will never happen, but, like the super-conducting, supersonic, subterrainian world-spanning train, a man can dream can't he?
Cordially.TA
BTW I showed the math, and as always, invite criticisms on my assuptions... (other thread.)
extinct
2 / 5 (4) Jan 15, 2013
Desperately lacking once again in this article is the ability for humans to think outside the box... that's my opinion. Now, opinions aside, here are two facts: 1) Hemp can be grown pretty much in any climate, naturally and organically without chemicals. Unlike corn, hemp actually thrives in stressful environments with high heat, high ultraviolet radiation, etc. 2) Hemp seed is the one and only food source on the planet that provides 100% complete nutrition to human beings. Please look it up. You could eat hemp seed (and drink water) exclusively for your entire life without eating anything else, and you'd get complete nutrition; you'd never come up with a nutritional toxicity or a nutritional deficiency. If you tried that same experiment with any other staple food of your choice, like exclusively eating corn, meat, milk, bread, beans, or soybeans, etc., those would each cause toxicities and deficiencies. So... these big brained people need to think outside the box... promote hemp.
VendicarD
3.2 / 5 (5) Jan 15, 2013
The inventor of the computer language LISP once told me that his solution to UV damage to plants in Europe caused by ozone depletion would be to cover all of Europe in a layer of sandwich wrap.

He was also fond of demanding that da gubderment permit him to eat a gram of plutonium.

"Have you ever seen how absolutely huge the fields are that feed a populace?" - Antilias

John McCarthy is dead now.

The world is an intellectually better place for it.
VendicarD
3 / 5 (6) Jan 15, 2013
"a man can dream can't he?" - Alchemist

A reasonable man does not offer his fantasies as a solution to real problems.

Children however, often do, since they can't distinguish reality from fantasy as well as rational men.

What is your excuse?

VendicarD
3.4 / 5 (5) Jan 15, 2013
antialias_physorg
4 / 5 (4) Jan 15, 2013
"when was the last time you built the pyramids?"

The pyramids are peanuts compared to the putting roofs on all the fields.
You really lack all sense of realism/scale when 'thinking' about things. You're so proud of your math. Try doing some next time before venturing a comment.

You're probably one ofthose people that think that 'setting up a breathable atmosphere' on another planet or 'moving an asteroid of several hundred meters diameter' is not much more difficult than getting a shoe box sized probe there.

You really ought to try this "real life" thing once in a while. It's fascinating, I assure you.

Yes, it would be a huge endeavor,

This isn't super-trains. This is ORDERS and ORDERS of magnitude more. Your naiveté is shocking. How old are you? 12?
The Alchemist
1 / 5 (2) Jan 16, 2013
Wow, everyone is so threated by even whimsical statements by The Alchemist.
"The pyramids" is just a stock phrase.
Would you prefer, in terms of orders of magnitude...
When was the last time you...
Built the Great Wall...
Built the roads and highways of the world...
Went to the Moon?

I guess "my excuse" is I am not afraid of endeavor, matching my strength and blood against what the majority think is impossible and trying to make my surroundings better.

But really, would putting down an irrigation layer underneath a farm be so impossible? Would putting up a durable layer of plastic be so expensive?
Perhaps so... but food is more important than the security the Chinese got, an interesting question compared to infrastructure, and going to the moon, well, that was pure spirit.
Peace guys, and cordially... (sincerely, without sarcasm).
antialias_physorg
3.7 / 5 (3) Jan 16, 2013
Built the Great Wall...

The great wall is peanuts compared to this.
It's 2400km long and 9m wide. Total area covered: 21.6 square kilometers.
Closer to home for you:
All the roads and parking lost in the US cover roughly 160000 square kilometers.

Agricultural area of the world: Roughly 50 million square kilometers.

If you don't see the difference here you're stone crazy.

I guess "my excuse" is I am not afraid of endeavor

Lazyness (of thought) is not an excuse. Learn to think in real(istic) dimensions. Proposing unattainable castles in the sky is not science and not creativity or innovation. Relitycheck your brainfarts BEFORE posting. Please.
That is the minimum courtesy/effort you should expend on a science site.

The innovative (and useful) thinker is the one who proposes a method that can be REALISTICALLY implemented. Postulating something that takes infinite resources or time isn't helpful. It just wastes bandwith.
The Alchemist
2.3 / 5 (3) Jan 16, 2013
I must have really hit a nerve. Your comparisons are non-sequitor. But then so were mine. I just wanted a little thought in that direction, not some sort of war where I refuse to fight with other than rubber weapons. If you're trying desperately to discredit me, this is not the place, 1, and 2, why? (retorical...)
Signing off this post.
rubberman
4 / 5 (4) Jan 16, 2013
I have a whole sea can full of rubber weapons....then of course...
antialias_physorg
3.7 / 5 (3) Jan 16, 2013
I just wanted a little thought in that direction

So do I. Expend some before posting. It's tiring to have to explain to people like you over and over again why the sky isn't green - when they could expend the minimal energy to just open their eyes and look for themselves.

If you're trying desperately to discredit me, this is not the place,

But it IS the place to tell you that you are lazy, uneducated fool. This is NOT done for the sake of discrediting you.
This is done so that you please STOP being a lazy uneducated fool spamming lazy, uneducated posts in comment sections where people would prefer to see a certain quality of discussion.

If nobody told you that you are lazy, uneducated fool you'd never know and just keep doing what you are currently doing. Stop. Just stop. It's hurting this site.
equalwatts
4 / 5 (4) Jan 20, 2013
If antialias's data is correct:
US roads and parking lots = 160,000 sq km
Global agricultural area = 50,000,000 sq km
Then his contention that The Alchemist's mild musing is absurd is actually incorrect.
First, let us extrapolate from antialias's data two additional data points.
1) Since, it is well established that indoor agriculture yields per square area are ~ 10X that of outdoor agriculture. Depending upon crop, yield improvements range from 5X to 25X. Therefore indoor agriculture requires 1/10 the area of outdoor agriculture (and 1/20 the fresh water BTW).
2) Since the rest of the world has roads and parking lots roughly in proportion to energy consumption; and US today consumes ~1/6 of world energy.
Global indoor agriculture area =~ 5,000,000 sq km
Global roads and parking lots =~ 1,000,000 sq km

The Alchemist's musing is not off by "ORDERS and ORDERS of magnitudes" but only by ~ 5X.
Certainly not worthy of the sneering dismissal by so many commentators on this thread
ubavontuba
1 / 5 (4) Jan 20, 2013
Increasingly hot summer weather could cause a fall in crop yields over the next two decades unless farming techniques are improved more quickly, scientists at the University have found.
Well, as some of the most productive farmland in the world is also in one of the hottest regions in the world (California's central valley), why don't they just adapt to these methods?

"Summer daytime temperatures approach 100 °F (38 °C), and common heat waves might bring temperatures exceeding 115 °F (46 °C)."

"On less than 1 percent of the total farmland in the United States, the Central Valley produces 8 percent of the nation's agricultural output by value:"

http://en.wikiped...iculture

ryggesogn2
2 / 5 (5) Jan 20, 2013
Latest tempearatue anomaly: .2C.
http://www.drroys...ratures/
obama_socks
1 / 5 (5) Jan 20, 2013
"when was the last time you built the pyramids?"

The pyramids are peanuts compared to the putting roofs on all the fields.
You really lack all sense of realism/scale when 'thinking' about things. You're so proud of your math. Try doing some next time before venturing a comment.

You're probably one ofthose people that think that 'setting up a breathable atmosphere' on another planet or 'moving an asteroid of several hundred meters diameter' is not much more difficult than getting a shoe box sized probe there.

You really ought to try this "real life" thing once in a while. It's fascinating, I assure you.

Yes, it would be a huge endeavor,

This isn't super-trains. This is ORDERS and ORDERS of magnitude more. Your naiveté is shocking. How old are you? 12?
-auntiealice

Well, it looks like you have flunked the test, AA

You have managed to make a display of your rigid intolerance. You have managed also to insult one of the best scientists worldwide...bar none.
ValeriaT
1 / 5 (2) Jan 20, 2013
So far the biofuels raised the price of food way more, than the global warming. The investments into cold fusion research would remove both the need to burn the food in form of biofuel, both the devastation of tropical forests with biofuels, which accelerates the spreading of droughts, both the carbon emissions released with burning of fossil fuels.
obama_socks
1 / 5 (5) Jan 20, 2013
The oceans on Earth will begin to boil away in approx. ~800 million years when the sun has exhausted all or most of its fuel and starts its expansion. 800 million years from now may seem like a very long way off, but in the general scheme of Earthly things, it can be like the blink of an eye. Of course, to us humans who are still (generally) Earth-bound at this time and may always be so, it is simply an iteration to say that we (or our posterity) MUST find ways to get off this planet and move out to intra-galactic space before our descendants of the far future are baked, boiled or fried.

Global warming/climate change is an outrage to our sensibilities (and sensitivities) which are well attuned to enjoying our creature comforts and our waiting impatiently for the next batch of technology that will give us continued self-gratification. But that self-gratification comes with a steep price and most people (especially the poor) are very UNwilling to give up what they consider precious.

obama_socks
1 / 5 (5) Jan 20, 2013
Before the advent of central heating with coal and then with oil and gas, the deforestation was necessary to heat homes, heat water and cook food. Married couples living on farms had numerous children and one of the reasons for large families was the infant and children mortality rate was high in some areas. Then, when better living conditions and life-saving pharmaceuticals became available to most everyone, those who could afford it, bought...cars.

So, one of our creature comforts is riding around in a car because 1) it offers protection, 2) it gets us to our destination usually in a timely manner, 3) you don't have to feed it oats and hay.
And now, we find ourselves possibly needing to go back to those wonderful but labor intensive horse and buggy days because WE are being blamed for (allegedly) causing the globe to warm and the climate to change.
obama_socks
1 / 5 (5) Jan 20, 2013
But guess what!! NOBODY seems to want the responsibility of telling us what we MUST give up. They just say, "stop the drilling for oil" and "stop digging for coal" and "stop fracking".
So they tell us that we MUST have alternative energy and they build solar arrays that use a great amount of space; they build wind farms and hydroelectric dams, etc.
But most power companies still get the electricity that they sell to us from...coal, gas and nuclear.
Why? Because it's inexpensive mostly and...it's available. Nobody wants to freeze in winter and bake in summer as our ancestors did. But these are the things we will have to do to try and stop AGW.
To stop AGW, we will have to forego our creature comforts and our love of brand new technology. But, what of people like Al (Al Jazeera) Gore and his LearJet trips to everywhere, who turned out to be a friend of Middle East oil? What of the 84 Obama vacation trips on AirForceOne to Hawaii, etc?. When is AlGore and Obama getting a horse and buggy??
VendicarD
3.8 / 5 (4) Jan 21, 2013
Isn't it interesting how Christie's chosen zero point continues to rise as global temperatures go up?

"Latest tempearatue anomaly: .2C." - RyggTard

And isn't it interesting how the years below 1998 have negative average temperatures in Christie's plot.

Why do you think that is Tard Boy?
VendicarD
4.2 / 5 (6) Jan 21, 2013
Translation, Sox is 12 years old.

"You have managed also to insult one of the best scientists worldwide...bar none." - Sox

"But guess what!! NOBODY seems to want the responsibility of telling us what we MUST give up" - Sox

Grow up Retard.
obama_socks
1 / 5 (3) Jan 21, 2013
Translation, Sox is 12 years old.


Bad guess, Venditardtard

"You have managed also to insult one of the best scientists worldwide...bar none." - Sox


Not too surprising that Venditardtard replies to a comment said to someone else. Poor lonely tard that VendiDtardtard

"But guess what!! NOBODY seems to want the responsibility of telling us what we MUST give up" - Sox


So Venditardtard doesn't like my little short essay...and yet offers nothing of value in response. What a droll little Venditardtard

Grow up Retard. That's what my retard girlfriend tells me every day since she got knocked up.
-says VenditarDeTardTard

obama_socks
1 / 5 (3) Jan 21, 2013
hmmm...Venditardietardietardtard may have a problem with my mentioning Al(Al Jazeera)Gore. Yes...THAT AlGore who sold his CurrentTV to Al Jazeera for ~$100 million (US) so that he could beat the Obama deadline to keep from paying enormous taxes from the sale. Al Jazeera, as we all know, is based in Qatar, a country known for BIG OIL.
But as we all knew from the start, Al Gore IS all about money and flying in Lear Jets. He talks the talk, but he can't bring himself to walk the walk.

Venditartardtard likes big Al. And the third Al is...Al Qaeda.....ta da

http://www.usatod...1805685/
TheGhostofOtto1923
1 / 5 (4) Jan 24, 2013
The Alchemist's musing is not off by "ORDERS and ORDERS of magnitudes" but only by ~ 5X. Certainly not worthy of the sneering dismissal by so many commentators on this thread
Yeah AAs bluster is getting embarrassing. I suspect it is intestinal in nature. And no response I see.

People are also considering alternatives: http://en.wikiped..._farming

-And with the coming revolution in fully-automated manufacturing and construction, covered farming could explode. And coupled with fully-automated farming and processing, yields could could explode as well.
http://www.ecofri...ing.html
http://www.future...tag=/sea water greenhouse
http://www.spacea...ohen.pdf