Global warming: More insects, eating more crops

August 30, 2018, University of Vermont
Credit: CC0 Public Domain

Crop losses for critical food grains will increase substantially as the climate warms, as rising temperatures increase the metabolic rate and population growth of insect pests, according to new research.

"Climate change will have a negative impact on crops," said Scott Merrill of the University of Vermont, a co-author of the study published today in Science. "We're going to see increased pest pressure with ."

The research team looked at how the insect pests that attack three staple crops—rice, maize and wheat—would respond under a variety of climate scenarios. They found that rising global temperatures would lead to an increase in crop losses from insects, especially in temperate regions. Losses are projected to rise by 10 to 25% per degree of warming.

Just a 2-degree rise in will result in total crop losses of approximately 213 million tons for the three grains, the researchers say.

Insects like it hotter—up to a point

The losses will come from an increase in insect metabolism, and from faster insect rates. The link with metabolism is straightforward. "When the temperature increases, the insects' metabolism increases so they have to eat more," said Merrill, a researcher in UVM's Dept. of Plant and Soil Science and Gund Institute for Environment. "That's not good for crops."

The link with growth, however, is more complex. Insects have an optimal temperature where their population grows best. If the temperature is too cold or too hot, the population will grow more slowly. That is why the losses will be greatest in temperate regions, but less severe in the tropics.

"Temperate regions are not at that optimal temperature, so if the temperature increases there, populations will grow faster," said Merrill, an ecologist who studies plant-crop interactions. "But insects in the tropics are already close to their optimal temperature, so the populations will actually grow slower. It's just too hot for them."

Key grain crops to take a hit

According to the study, wheat, which is typically grown in cool climates, will suffer the most, as increased temperatures will lead to greater insect metabolism, as well as increased pest populations and survival rates over the winter. Maize, which is grown in some areas where population rates will increase and others where they will decline, will face a more uneven future.

In rice, which is mostly grown in warm tropical environments, crop losses will actually stabilize if average temperatures rise above 3°C, as population growth drops, counteracting the effect of increased metabolism in the pests. "Rice losses will taper off as the rises above a certain point," said Merrill.

That means that the most substantial yield declines will happen in some of the world's most productive agricultural regions. "The overall picture is, if you're growing a lot of food in a temperate region, you're going to be hit hardest," said Merrill.

"I hope our results demonstrate the importance of collecting more data on how pests will impact crop losses in a warming world—because collectively, our choice now is not whether or not we will allow warming to occur, but how much warming we're willing to tolerate," said Curtis Deutsch of the University of Washington, who co-led the study with Joshua Tewksbury, director of Future Earth at the University of Colorado, Boulder.

France, China and the United States, which produce most of the world's maize, are among the countries that are expected to experience the largest increases in crop losses from . France and China, as major producers of wheat and rice, respectively, are also expected to face large increases in losses of those grains as well. "The areas that produce the most grain, especially wheat and corn—the US, France and China—are going to be hit hardest," said Merrill.

Reduced yields in these three staple crops are a particular concern, because so many people around the world rely on them. Together they account for 42% of direct calories consumed by humans worldwide. Increased will result in a rise in food insecurity, especially in those parts of the world where it is already rife, and could lead to conflict.

As farmers adapt to a changing climate by shifting planting dates or switching to new cultivars, they will also have to find ways to deal with pests, by introducing new crop rotations, or using more pesticides. But not all of these strategies will be available to all farmers. "There are a lot of things richer countries can do to reduce the effect, by increasing pesticide use or expanding integrated management strategies," said Merrill. "But poorer countries that rely on these as staple grains will have a harder time."

Explore further: Africa's most notorious insects – the bugs that hit agriculture the hardest

More information: C.A. Deutsch el al., "Increase in crop losses to insect pests in a warming climate," Science (2018). science.sciencemag.org/cgi/doi … 1126/science.aat3466

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Hyperfuzzy
1.8 / 5 (5) Aug 30, 2018
Move the crops in doors.
Hyperfuzzy
1 / 5 (3) Aug 30, 2018
Think about it Re engineer the surface! Think volume! Necessary and Sufficient; with apologies to nature; not insults.
Hyperfuzzy
1 / 5 (3) Aug 30, 2018
You'll have surfaces left.
grandpa
1.4 / 5 (9) Aug 30, 2018
Lions Tigers and Bears! Oh my!
eachus
1 / 5 (3) Aug 30, 2018
Much easier: move sensitive crops further North (and South in the Southern Hemisphere). The other solution is to stop monoculture. Didn't anyone learn from the Irish potato famine? If you rotate crops over large enough areas, the pests will tend to die off before the same crop is grown in that area again.

Doesn't mean you can grow corn this year and corn the next, there are about 100 varieties of corn that can be planted where I live (Southern New Hampshire), and there is nothing better than corn picked from the field and eaten within hours. ;-)
Hyperfuzzy
1 / 5 (4) Aug 30, 2018
Too cheap to prepare for the future?
philstacy9
1.7 / 5 (10) Aug 30, 2018
Even if this speculation were true it wouldn't be as bad as socialist government control causing mass starvation in Venezuela.
TrollBane
4 / 5 (4) Aug 30, 2018
Hyperfuzzball: "You'll have surfaces left."
Going by your comment history, that's an apt self-characterization.
Shootist
2 / 5 (8) Aug 30, 2018
Call me when barley, wheat and cattle have been raised on Greenland. For 400 years.
eachus
3 / 5 (4) Aug 30, 2018
Call me when barley, wheat and cattle have been raised on Greenland. For 400 years.

Like now? During the Medieval Warm Period you get pretty close to your 400 years--well for about a century after the end of the MWP the colonists in Iceland tried to carry on, but near the end, their diet was mostly fish.

Now agriculture in Greenland is flourishing again. There is a small herd of cattle, winter wheat is easy, I don't know about barley. Oh, and one of the advantages of agriculture in Greenland is the pest free nature.

If you look at a globe, Greenland isn't that big. Agriculture migrating North in Siberia could feed the whole earth.
dudester
4 / 5 (4) Aug 30, 2018
I can assure the flat earthers above that no matter the temperature, at higher latitudes insufficient light/hours hit the ground for plants-- especially the domesticated crops our ancestors have been developing for the past several millennia from the equators to the furthest reaches of the arable temperate zones-- to engage in the photosynthesis necessary for mere existence, let alone the amount of energy needed to produce quantities of sugars, fats and proteins sufficient to produce surplus food.
Crop pests aren't so highly specialized that crop rotation in the absence of hard fall freezes and multiple killing cold snaps over the winter will slow them down. They wake up in spring and take off where they left off in autumn with little "kill back". Weeds are the same. When I was little, winters were so cruel working outside. My fingers and toes were always numb. Not today. No fall to speak of, then a mild winter, a dry spring, then blazing summer. Our crops are not "built" for that.
cantdrive85
1.5 / 5 (8) Aug 30, 2018
When I was little,

You mean when you were Chicken Little?
Bob Osaka
4.8 / 5 (4) Aug 31, 2018
This contradicts credible research indicating a 74% decline in flying insects in the last 27 years and a 60% loss of animal biodiversity through extinction since 1970. It reads like an advertisement for pesticides or technological equipment for vertical hydroponic agriculture. Not one species is mentioned other than collectively calling them "insect pests."
Forecasting the future by looking into a crystal ball isn't as useful as recalling the buzz of insect activity occurring around street lamps during summer months and looking tonight and counting little to none.
eachus
1 / 5 (3) Aug 31, 2018
I can assure the flat earthers above that no matter the temperature, at higher latitudes insufficient light/hours hit the ground for plants-- especially the domesticated crops our ancestors have been developing for the past several millennia from the equators to the furthest reaches of the arable temperate zones-- to engage in the photosynthesis necessary for mere existence, let alone the amount of energy needed to produce quantities of sugars, fats and proteins sufficient to produce surplus food.
I am not a flat earther, I am also able to read a map, In addition I have children (and grandchildren) living in Alaska and London. The Earth's tilt with respect to its orbit means that at midsummer, the sun is (a bit) higher in the sky at 45 degrees North, than at the equator. I wouldn't try growing mangoes in Sweden, but the issue isn't sunlight, it is the short growing season. It could probably be done in a greenhouse--but heating it in the winter would be much to costly.
TrollBane
5 / 5 (1) Aug 31, 2018
About agriculture migrating north, that warmth is only part of it. Soil types, lingering permafrost, the short growing season (as you mention) and access to market are impediments to that. That, and getting people with the needed skills to live there. And yes, modern agriculture needs skills. Yes, heating a greenhouse in the long winter nights could be tough, but unless you are talking about the very far north/south there is still some sunlight year round. There may be plenty of wind and wave power available for powering grow lights and heat. There has been a greenhouse operating in Inuvik (Northwest Territories, Canada) for twenty seasons, so it can be done. https://inuvikgreenhouse.com/
Joker23
1 / 5 (3) Aug 31, 2018
BIG numbers 213000000 tons!!!!!!!!!! Which amounts to about ..156 pounds per person per day or about 2.5 ounces per person per day. Little NUMBERS. More than that is wasted every day from spoilage.......in short not significant..................Maybe'll Vermont(?), funny place for such a study since, last time I checked their contribution to the World's food supply is insignificant, needs some more funding for more studies.
antigoracle
1.9 / 5 (9) Aug 31, 2018
GloBULL Warming: More lies, creating more bullshit.

There, fixed that headline.
According to AGW Cult lore, when did manmade gloBull warming begin?
How much has the human population increased during that time?
How much has food production increased to sustain that population?

The US wastes 40% of its food, and yet sustain the fattest population on the planet. The TRUE PARASITES, created by GloBULL Warming, are those in the AGW Cult, who believe CO2 is destroying the planet, yet continue to burn fossil fuels, as if there is no tomorrow. This is just more Pathological LIES from the AGW Cult and their Pathological "science". The Chicken Littles must be hungry.
antialias_physorg
3.7 / 5 (6) Aug 31, 2018
156 pounds per person per day or about 2.5 ounces per person per day.

Erm...this makes no sense.

BIG numbers 213000000 tons

Reading seems to be a lost art. This is for the three grains. There's other agricultural products than those, too, you know?

At current prices we're dealing with a loss in the range of 50bn US dollars for these grains alone - which would have to be paid out to farmers from (your) taxes in form of subsidies to keep them afloat. Every single year from then on.
antialias_physorg
3.9 / 5 (7) Aug 31, 2018
I really don't get the kind of mentality behind saying "this is peanuts".

When your car leaks oil what do you do:
1) Fix the leak for 100 dollars
or
2) Keep topping off the oil for 50 dollars every year...forever?

Old_C_Code
1 / 5 (5) Aug 31, 2018
And so a cooling planet will help crops? You can't win with these endless BS articles. It's people/society that keep asking for oil you nit wit. It didn't start with them saying "hey, how can we make big bucks off of people?"... people want oil, and continue to demand it, you dope.
Hyperfuzzy
1 / 5 (2) Aug 31, 2018
Wow! See it! Saw it coming. Know why, how, how much, when. Have tech focused upon cellular communication 'cause $. We know that everything can be controlled, made better by logical design. Yet we do not fix self. We'd rather imagine that we are created by Logic or meh? Not only is there enough for everybody, the world is bountiful! Starvation? I'll watch this #hit on live TV! NONSENSE! Been disobedient for 4000 years.
gkam
4 / 5 (4) Aug 31, 2018
Hey, C code, I do not need oil or gasoline.

Sorry about you and your addiction to it.
Old_C_Code
1 / 5 (3) Aug 31, 2018
gkam: Yes you do. Unless you live in the woods with solar and fireplaces, and make a living weaving baskets. But the fact that you are online, indicates oil usage.
gkam
4 / 5 (4) Aug 31, 2018
Nope. My household is powered by the PV panels on the roof, which also power my cars.

Nobody burns oil for power anymore.
Hyperfuzzy
1 / 5 (2) Aug 31, 2018
Collective Thinking for the last 4000 years!
barakn
5 / 5 (5) Aug 31, 2018
Call me when barley, wheat and cattle have been raised on Greenland. For 400 years. -Shootist
No evidence for wheat growing there at all. Zip, zilch, nada. The evidence for barley consists of a few scorched grains in a single layer at the bottom of one trash heap. "The find also substantiates a well-known text from about 1250, 'King's mirror (Konungs skuggsjá)', which mentions in passing that the Vikings attempted to grow grain on Greenland. It is the only report about cultivating barley that we have from that time and says: "As to whether any sort of grain can grow there, my belief is that the country draws but little profit from that source. And yet there are men among those who are counted the wealthiest and most prominent who have tried to sow grain as an experiment; but the great majority in that country do not know what bread is, having never seen it."" https://ancientfo...eenland/

Old_C_Code
1 / 5 (4) Aug 31, 2018
"Nobody burns oil for power anymore".. I knew you were an idiot.
Hyperfuzzy
1 / 5 (1) Aug 31, 2018
Call me when barley, wheat and cattle have been raised on Greenland. For 400 years. -Shootist
No evidence for wheat growing there at all. Zip, zilch, nada. The evidence for barley consists of a few scorched grains in a single layer at the bottom of one trash heap. "The find also substantiates a well-known text from about 1250, 'King's mirror (Konungs skuggsjá)', which mentions in passing that the Vikings attempted to grow grain on Greenland. It is the only report about cultivating barley that we have from that time and says: "As to whether any sort of grain can grow there, my belief is that the country draws but little profit from that source. And yet there are men among those who are counted the wealthiest and most prominent who have tried to sow grain as an experiment; but the great majority in that country do not know what bread is, having never seen it."" https://ancientfo...eenland/


Such is your design?
gkam
3 / 5 (4) Aug 31, 2018
C code, how many oil-fired powerplants have you been in lately? Ever?

I was in a few in the early 1980s, but no more.
What do yours burn, . . . tallow?
Old_C_Code
1 / 5 (3) Aug 31, 2018
Half the houses on the east coast and midwest have oil burners for heat. But that's no one to you.
gkam
3 / 5 (4) Aug 31, 2018
We are talking powerplants.
howhot3
4.2 / 5 (5) Sep 01, 2018
This should be a real DUHHHH moment for all the climate denier goons, It should be stupidly obvious that if you warm the atmosphere from fossil fuel use, you will make the insects breed more. Grass-hoppers, Beatles, Aphids (Oh my)! Grass-hoppers, Beatles, Aphids (Oh my)! Grass-hoppers, Beatles, Aphids (Oh my)! They are not good for crops.

Let's just say its one more side note in the development of a "Soylent Green" type of Extinction event for our planet from global warming. If the heat doesn't get you the bugs will.
Old_C_Code
1 / 5 (4) Sep 01, 2018
We are talking burning oil. You are ignorant, and have little idea how to help this world.
Old_C_Code
1 / 5 (4) Sep 01, 2018
howhot3: lol, you such a little frightened baby. And colder is better, got it.
Old_C_Code
1 / 5 (4) Sep 01, 2018
"the world achieved a new oil production record of 92.6 million barrels per day... in 2017"
gkam
3 / 5 (2) Sep 01, 2018
C code thinks personal attacks help his cause of polluting us out of existence.

Oil is dying. That is why the Saudi want to sell theirs before it is pumped out.
gkam
3.7 / 5 (3) Sep 01, 2018
As much as I liked their music, I do not think the beatles will come back, howhot.

And the Koch Brothers own the Soylent Corporation.
eachus
5 / 5 (1) Sep 01, 2018
No evidence for wheat growing there at all. Zip, zilch, nada.
Agreed, we could do it today, if it made economic sense, but the winter wheat varieties available today were not available to the Vikings
The evidence for barley consists of a few scorched grains in a single layer at the bottom of one trash heap.
Of course the rich grew barley, otherwise they would have to import it to make beer. (The Germans have a beer, weissbier made mostly from wheat, and evidence for it dates back to 800 BC. But it wasn't very popular when the Vikings were in Greenland.)
eachus
5 / 5 (1) Sep 01, 2018
"the world achieved a new oil production record of 92.6 million barrels per day... in 2017"
And this year will set a new record.

To the extent that oil replaces coal, and natural gas replaces oil the amount of CO2 per quad of energy goes down. In the US we are skipping the intermediate step: replacing coal plants for generating electricity with combined-cycle gas plants which are also more efficient. Oh, and the US is now a net oil exporter for the first time in decades.

But the real solution to the energy problem is not fusion but nuclear fission plants. See lots of discussion mostly filed under thorium about a generation of molten salt reactors (MSR) It turns out that thorium is a better fuel than uranium for MSRs, thus liquid fluoride thorium reactors (LFTR). But you don't need to use thorium to get most of the safety benefits of MSRs. It is just that thorium is literally dirt cheap compared to uranium. It is a waste product from rare earth mining.
gkam
3.7 / 5 (3) Sep 01, 2018
We do not need nukes. We can do it with renewables.
eachus
5 / 5 (1) Sep 01, 2018
We do not need nukes. We can do it with renewables.


Thorium fueled nuclear plants should count as renewables. There is about 4 times as much thorium as uranium, and thorium is mined as a byproduct of rare earth mining. Both almost details. 0.7% of uranium is U235, almost all the rest is U238. U235 is capable of self-sustaining fission, U238 is not. If you convert the U238 in a reactor into Plutonium239 that fissions, Pu240 does not. So to use U238 as a fuel you have to put it in a reactor fueled with something else, and refine the Pu239 out of the spent fuel before too much of it becomes Pu240.

What about thorium in molten salt reactors? It doesn't fission, but all of it is Th232, pick up a neutron and you get Th233, which decays quickly to Pa233 then with a half-life of 29 days to U233. That is the fuel you need to start the cycle all over. So Thorium reactors not only do not produce transuranics, they can be burned up in MSRs.
eachus
not rated yet Sep 01, 2018
We can do it with renewables.
Sorry, we can't. Current renewables, mostly hydro and tidal, makes a reasonable addition to other sources of electricity. But you want the light to go on when you flip the switch. That is not a big problem, but some industrial plants, for example steel recycling plants, need that capability on a huge scale. So the electricity network needs to respond to fluctuations in demand, immediately, and in large chunks. What happens when you add wind and solar to the network. They provide some power, but it varies, and the resiliency the network needs for large industrial users gets used up. Hydro provides the best edge handling for spikes in demand. Gas cogeneration plants are nice for swing load, and coal and nuclear are best at base load.

If you want to put solar panels on your roof? Go ahead. The subsidies make it look profitable, and if you lose mains power, you MAY be able to keep the fridge and some lights going. (Check with installer.)
gkam
3.7 / 5 (3) Sep 01, 2018
Yes, I was Plant Engineer of a foundry and understand the arc furnaces in steel plants very well. There is one in Australia which how gets much of its power from renewables in a 20-year contract. I do not remember if it is from wind or PV.

I was also a utility engineer in Technical Services and understand power generation, delivery and utilization.

BTW, I have a PV system which powers my household and two electric cars. Do I have to explain how I put it in the system in the daytime and take it out at night?

Oh, . . we also have Tesla batteries now, too, so we can get by, thanks.
gkam
3.7 / 5 (3) Sep 01, 2018
"If you want to put solar panels on your roof? Go ahead. The subsidies make it look profitable, and if you lose mains power, you MAY be able to keep the fridge and some lights going"

No, the inverters of PV systems are slaved to powerline frequency, and do not have their own clock. My household batteries do have the ability to provide AC power without a grid connection.

They are charged by the Sun.
Hyperfuzzy
1 / 5 (2) Sep 01, 2018
"If you want to put solar panels on your roof? Go ahead. The subsidies make it look profitable, and if you lose mains power, you MAY be able to keep the fridge and some lights going"

No, the inverters of PV systems are slaved to powerline frequency, and do not have their own clock. My household batteries do have the ability to provide AC power without a grid connection.

They are charged by the Sun.

You have not reviewed Tesla Battery Storage out the box; solar, .. OK

Any decent grid has manageable storage; how else to you manage? Oh 4got amuriraca, so use oil.
cantdrive85
1.7 / 5 (6) Sep 02, 2018
"the world achieved a new oil production record of 92.6 million barrels per day... in 2017"


It's quite amusing the scare tactics that are used on folks. About 10-years ago we had achieved "Peak Oil" and we were dooming our society with our reckless usage. What has happened? Amerika has tripled its output and has become the number one producer of hydrocarbons on the planet. It has been shown Peak Oil was a scam, and someday in the near future it will be shown AGWism is also a gigantic scam used to manipulate the populous.
Very fortunately for we Amerikans, we have been saved from complete economic/currency meltdown due to the tremendous increase in hydrocarbon production and exports.
gkam
3.7 / 5 (3) Sep 02, 2018
"You have not reviewed Tesla Battery Storage out the box; solar, .. OK"

Fuzzy, I do not understand what you are getting at.

And can'tdrive will really enjoy thinking of me when he gets his first electric car.
RichardBlumenthal
1.8 / 5 (5) Sep 02, 2018
Killing millions and millions of insect-eating birds and bats with foolish wind turbines has had quite an impact, hasn't it?
gkam
3.4 / 5 (5) Sep 02, 2018
No it hasn't.

Ever been below a utility-scale wind turbine? I have. No dead birds.
TheGhostofOtto1923
1 / 5 (1) Sep 06, 2018
Yes, I was Plant Engineer of a foundry and understand the arc furnaces in steel plants very well
-until you got canned because, well, they found out you didnt understand the arc furnaces in steel plants very well because you werent really an engr.

Shoppers come and shoppers go. George kamburoff might be a major factor in the advent of HR depts tho, a laudible accomplishment.
gkam
5 / 5 (2) Sep 06, 2018
Iron foundries do not use arc furnaces, they use induction furnaces, and we had three. Let me watch you stand in the same room when a 40MW arc furnace strikes an arc.
zz5555
5 / 5 (2) Sep 06, 2018
Killing millions and millions of insect-eating birds and bats with foolish wind turbines has had quite an impact, hasn't it?

Coal, oil & gas, and even nuclear kill many more birds than wind - so the more wind is used to replace other energy sources, the better for the birds. And better placement of windmills has reduced bird loss. Additionally, global warming/climate change kill more birds, so anything to lessen that has to be considered a plus.

Regardless, all energy sources combined kill < 10,000,000 birds a year in the US (mostly from coal). Cats kill billions of birds every year, so windmill deaths are very insignificant in comparison.

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