Climate change and air pollution will combine to curb food supplies

Jul 27, 2014 by David L. Chandler, Mit News Office

Many studies have shown the potential for global climate change to cut food supplies. But these studies have, for the most part, ignored the interactions between increasing temperature and air pollution—specifically ozone pollution, which is known to damage crops.

A new study involving researchers at MIT shows that these interactions can be quite significant, suggesting that policymakers need to take both warming and air pollution into account in addressing food security.

The study looked in detail at global production of four leading food crops—rice, wheat, corn, and soy—that account for more than half the calories humans consume worldwide. It predicts that effects will vary considerably from region to region, and that some of the crops are much more strongly affected by one or the other of the factors: For example, wheat is very sensitive to , while corn is much more adversely affected by heat.

The research was carried out by Colette Heald, an associate professor of civil and environmental engineering (CEE) at MIT, former CEE postdoc Amos Tai, and Maria van Martin at Colorado State University. Their work is described this week in the journal Nature Climate Change.

Heald explains that while it's known that both higher temperatures and ozone pollution can damage plants and reduce , "nobody has looked at these together." And while rising temperatures are widely discussed, the impact of air quality on crops is less recognized.

The effects are likely to vary widely by region, the study predicts. In the United States, tougher air-quality regulations are expected to lead to a sharp decline in ozone pollution, mitigating its impact on crops. But in other regions, the outcome "will depend on domestic air-pollution policies," Heald says. "An air-quality cleanup would improve crop yields."

Overall, with all other factors being equal, warming may reduce crop yields globally by about 10 percent by 2050, the study found. But the effects of ozone pollution are more complex—some crops are more strongly affected by it than others—which suggests that pollution-control measures could play a major role in determining outcomes.

Ozone pollution can also be tricky to identify, Heald says, because its damage can resemble other plant illnesses, producing flecks on leaves and discoloration.

Potential reductions in crop yields are worrisome: The world is expected to need about 50 percent more food by 2050, the authors say, due to population growth and changing dietary trends in the developing world. So any yield reductions come against a backdrop of an overall need to increase production significantly through improved crop selections and farming methods, as well as expansion of farmland.

While heat and ozone can each damage plants independently, the factors also interact. For example, warmer temperatures significantly increase production of ozone from the reactions, in sunlight, of volatile organic compounds and nitrogen oxides. Because of these interactions, the team found that 46 percent of damage to soybean crops that had previously been attributed to heat is actually caused by increased ozone.

Under some scenarios, the researchers found that pollution-control measures could make a major dent in the expected crop reductions following . For example, while global food production was projected to fall by 15 percent under one scenario, larger emissions decreases projected in an alternate scenario reduce that drop to 9 percent.

Air pollution is even more decisive in shaping undernourishment in the developing world, the researchers found: Under the more pessimistic air-quality scenario, rates of malnourishment might increase from 18 to 27 percent by 2050—about a 50 percent jump; under the more optimistic scenario, the rate would still increase, but that increase would almost be cut in half, they found.

Agricultural production is "very sensitive to ," Heald says, adding that these findings "show how important it is to think about the agricultural implications of air-quality regulations. Ozone is something that we understand the causes of, and the steps that need to be taken to improve air quality."

Explore further: Climate change increases risk of crop slowdown in next 20 years

More information: Threat to future global food security from climate change and ozone air pollution. Nature Climate Change. DOI: 10.1038/nclimate2317

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User comments : 18

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Vietvet
3.6 / 5 (14) Jul 27, 2014
Yet again a science denying troll gives an important story a one star ranking.
discouragedinMI
Jul 27, 2014
This comment has been removed by a moderator.
jonekat
1 / 5 (7) Jul 27, 2014
Air pollution in china and india effectively is a form of population control because it kills so many people ...so it will all even out
Shootist
2.5 / 5 (8) Jul 27, 2014
Air pollution in china and india effectively is a form of population control because it kills so many people ...so it will all even out


which is exactly why peoples life span's aren't increasing, everywhere around the globe, even the Indians and Chinese. cause they're all like dying and stuff . . . jeez
chrismcphail1
2.4 / 5 (14) Jul 27, 2014
The National Oceanic and Atmospheric Administration's most accurate, up-to-date temperature data confirm the United States has been cooling for at least the past decade. The NOAA temperature data are driving a stake through the heart of alarmists claiming accelerating global warming.

Responding to widespread criticism that its temperature station readings were corrupted by poor citing issues and suspect adjustments, NOAA established a network of 114 pristinely cited temperature stations spread out fairly uniformly throughout the United States. Because the network, known as the U.S. Climate Reference Network (USCRN), is so uniformly and pristinely situated, the temperature data require no adjustments to provide an accurate nationwide temperature record. USCRN began compiling temperature data in January 2005. Now, nearly a decade later, NOAA has finally made the USCRN temperature readings available.

According to the USCRN temperature readings, U.S. temperatures are not rising at all – at least not since the network became operational 10 years ago. Instead, the United States has cooled by approximately 0.4 degrees Celsius, which is more than half of the claimed global warming of the twentieth century.

Of course, 10 years is hardly enough to establish a long-term trend. Nevertheless, the 10-year cooling period does present some interesting facts.

Antarctica continues to defy the global warming script, with a report from Meteo France, that June this year was the coldest Antarctic June ever recorded, at the French Antarctic Dumont d'Urville Station.

According to the press release, during June this year, the average temperature was -22.4c (-8.3F), 6.6c (11.9F) lower than normal. This is the coldest June ever recorded at the station, and almost the coldest monthly average ever – only September 1953 was colder, with a recorded average temperature of -23.5c (-10.3F).

June this year also broke the June daily minimum temperature record, with a new record low of -34.9c (-30.8F).
ryggesogn2
1.6 / 5 (7) Jul 27, 2014
See the story on physorg about vertical farming.
Read Heinlein's The Moon is a Harsh Mistress.
Watch Silent Running.
Captain Stumpy
3.9 / 5 (12) Jul 27, 2014
driving a stake through the heart of alarmists claiming accelerating global warming.
@chrismcphail1
I guess this is your lucky day, Mcfail1!
IF you truly believe that "alarmists" are wrong about global warming, and you can prove it... feel free to go to this site and do so: http://dialogueso...and.html

The rules are simple. be 18 or older and prove, via the scientific method, that man-made global climate change is not occurring;
remember, entries do not have to be original, but they DO have to be first!

I suggest you take your arguments there and prove yourself... should you succeed, then you will gain admiration from the ENTIRE denialist camp, the big oil backing of the denialist regime (as proven HERE: http://www.drexel...nge.ashx ) but you would also bring attention to IMPORTANT WORK because the BULK of the empirical data is against you
Captain Stumpy
3.9 / 5 (11) Jul 27, 2014
Antarctica continues to defy the global warming script, with a report from Meteo France, that June this year was the coldest Antarctic June ever recorded, at the French Antarctic Dumont d'Urville Station.
@chrismcfail1

I suggest you talk to Runrig and learn some SCIENCE

until then... here is a nice video to watch.

https://www.youtu...m9JAdfcs

Based upon her study called out in the video.

Then go here: http://theconsens...ect.com/

Start learning about the OVERWHELMING evidence which is the ELEPHANT in the corner of the room that you are ignoring...

Thanks

ryggesogn2
2.5 / 5 (14) Jul 27, 2014
I suggest you talk to Runrig and learn some SCIENCE

An AGWite doesn't have to have a PhD in climate science to be an 'expert', but climate scientists with PhDs who do not toe the AGW line must be shouted down and ridiculed.
jonekat
1.9 / 5 (14) Jul 27, 2014
@Captain Stumpy

You realize that no amount of screeching AGW mem from the mount will change the fact that for 18 years there has been no global warming and that the most up to date climate monitoring system in the world (USCRN) has shown a .04 C cooling trend

We all know what happened to Chicken Little right, It may have happened to you already you just haven't realized it yet ;0)
antigoracle
1 / 5 (8) Jul 27, 2014
I suggest you talk to Runrig and learn some SCIENCE
--stuntytard
Well, he certainly does not want to talk to you, tard.
nilbud
4.2 / 5 (11) Jul 27, 2014
Why are Americans so susceptible to nonsense? Alex Jones would have starved to death in Europe by now. The drooling vegetables who imagine you can increase the population from 1 billion to 7 billion and burn huge amounts of oil, coal, and wood and have no effect whatsoever on the climate have to be the most stupid people to ever live on the planet.
antigoracle
1 / 5 (8) Jul 27, 2014
So nilbud, if you believe that, then why are you alive?
D_Dan Westeman
1.8 / 5 (10) Jul 27, 2014
YAWN. The "man-made climate change" fantasy rolls on...
Climate cultists are becoming more dangerous than islamists. They are just as anti-science and intolerant as islamists but soon they will be committing terror acts against those who refuse to believe their lies.
alfie_null
4.4 / 5 (9) Jul 28, 2014
YAWN. The "man-made climate change" fantasy rolls on...
Climate cultists are becoming more dangerous than islamists. They are just as anti-science and intolerant as islamists but soon they will be committing terror acts against those who refuse to believe their lies.

The overwhelming majority of scientists is hardly a cult. Then, the English language being so malleable, I suppose you can choose to redefine "cult" as all the people who say things you don't want to believe.

Care to try arguing the science, instead of just rehashing tired old rhetoric?
dogbert
1.6 / 5 (9) Jul 28, 2014
If the climate actually warms, the longer growing seasons and the ability to produce crops at higher latitudes would tend to increase food production.

Conversely, we might expect a cooling climate to shorten growing seasons and prevent farming at higher latitudes tending toward a decrease in food production.

Yet all discussions of climate change which presume a warming climate come with dire warnings that food production must decline.
ItsThatGuy
4 / 5 (4) Jul 28, 2014
Then wouldn't that lead you to believe that maybe the experts on the subject who have been doing the research might know something you don't? Explain what methods you think they used that were faulty, or what data they misinterpreted, and share with us your credentials. If you are not a agriculture scientist, botanist, or similar, what studies have you done that are the source of your disagreement with the research?
dogbert
1.5 / 5 (8) Jul 28, 2014
ItsThatGuy,
Then wouldn't that lead you to believe that maybe the experts on the subject who have been doing the research might know something you don't?


No. I am merely pointing out that when it comes to climate change (which always means anthropogenic global warming), the effects of that warming are always bad. There is never an up side to a warmer world.

This is to be expected when the predictions originate from a political agenda. A truly scientific examination of climate change would find positive and negative results from any change.
ryggesogn2
1.6 / 5 (7) Jul 28, 2014
Why are Americans so susceptible to nonsense? Alex Jones would have starved to death in Europe by now. The drooling vegetables who imagine you can increase the population from 1 billion to 7 billion and burn huge amounts of oil, coal, and wood and have no effect whatsoever on the climate have to be the most stupid people to ever live on the planet.

Why do Euros hate Jews?