Special feature 1

Behind the scenes: Talk with RIHN project leaders

Nitrogen is“everywhere”and we cannot see why it’s important
Research Project● Sustai-N-able (SusN): Towards Sustainable Nitrogen Use Connecting Human Society and Nature
Interviewee: Kentaro Hayashi, Professor
Interviewer: Ken-ichi Abe, Professor

Nitrogen (N) is the fifth most abundantelement in the solar system, and nearly
80% of the air is molecular nitrogen(dinitrogen, N2). Life on the Earthcannot live without N as an essential
component to form proteins andDNA. Whilst N offers great benefits
to humanity as fertilizer for foodproduction, raw materials for industrial
production and fuel, it always lays
behind every environmental issue.
Our N use unintendedly causes N
pollution, which has been gradually
undermining the health of people
and nature. “We cannot talk about the
future of our planet without looking
at N. Unless we look at the whole
picture of the complex N cycle, we will
be never able to solve environmental
issues,” says Prof. Hayashi. His projectʼsabbreviation, “Sustai-N-able,” with“nitrogen (N)” at the center, does
highlight his determination.
Abe●Your project has finally begun on full scaleas PR (Pre-Research) in FY2022. I can lookup your project’s overview in the ResearchInstitute for Humanity and Nature (RIHN)
Prospectus, and I have had some opportunities
to learn about the same as it has progressedfrom IS (Incubation Study) phase to FS(Feasibility Study), then to PR, but to be honest,
I still haven’t got the gist of it. Although I
understand that the project focuses on the N
issue, it’s just difficult for me to understandwhat your project is trying to archive.
First of all, the fact that N is one of the major
environmental issues is not well understoodeven by those of us who are conducting
research at RIHN.
Hayashi●Absolutely. It has been a constantquestion since the IS and FS phases. They
always told me, “I don't know why N is an issue”(laughs).
You also often asked me, and you would say,“I think I understood,” when I explained, butthen you would repeat, “I think I am confusedagain” (laughs).
Abe●Perhaps it’s because the N issue is socomplex, but I just felt like I was stuck in afathomless swamp.
Hayashi●I recently had some opportunities
to visit the Ministry of Agriculture, Forestry
and Fisheries (MAFF), the Ministry of the2every day. The air we breathe in contains 78%
nitrogen.

Useless N and usable N

Kentaro Hayashi

Environment, the Ministry of Economy,
Trade and Industry, and the Ministry of Land,
Infrastructure, Transport and Tourism to talkabout the N issue, and they all responded in thesame way. In a sense, I think it’s only fair, andtoday I would like to explain why that is so.
Abe●I can finally get out of the swamp (laughs).

How much do
we know about“N that is everywhere”?
Hayashi●Nitrogen is very important andessential but people just don't get that.
For example, living organisms need N to
make proteins and DNA. We, humans, canonly take in N by “eating” it. For us to produce
food to eat, we also need N as fertilizer. Plants
also need N to grow and to produce enzymes
necessary for photosynthesis.
Abe●I see. Then, it’s basically the same as when
we at RIHN do very conscious efforts to tell thegeneral public how important biodiversity is,but it’s difficult for them to understand. RIHN’s
first Director-General, Prof. Toshitaka Hidaka
always said, “so that high school students canunderstand,” but it’s quite difficult to convey
something so obvious. Nitrogen is “criticallyimportant” in this sense.
Hayashi●That’s exactly correct. It’s like breathing

Humanity & Nature Newsletter No.89 August 2023

Abe●Nitrogen is present everywhere in ourlives, plus a significant portion of our body iscomposed of protein containing N. And yet, wedon’t really know what the N issue is.
Hayashi●Actually, there are two types of N.
One is the most abundant N species in the airaround us, which basically “does nothing” inboth good and bad ways. This inert N species
is called “nitrogen gas (N2).” Although I just said
it would not do anything or useless, if the air
were composed only of N2 (chisso), we would
asphyxiate (chissoku) and die. This is how theJapanese name of N, or chisso comes fromchissoku.
Abe●Chisso (N) comes from chissoku(asphyxiation), I see.
Hayashi●In German, it’s “stickstoff,” meaning
asphyxiating substance, which was thentranslated directly into Japanese. Humanity
hadn’t known the existence of this “useless N
that does nothing” and only discovered thiselement in the late 18th century.
Abe●That’s why it’s so hard for people tounderstand when you tell them it’s an issue(laughs).
Hayashi●Exactly. It’s around us everywhere, andit really doesn’t do anything. Even when webreathe it in, it just goes in and out of our bodies
and it doesn’t build muscle or grow any otherorgans. So, we as animals have to eat “usable
forms of N.” Animals take in N compounds
such as protein and amino acids, and plants
take in forms of ammonium and nitrate.
Abe ●Do we call these “usable forms of N” active
N as opposed to inert N?
Hayashi●It’s called “reactive nitrogen (Nr).”
There are various forms of N, but all Ncompounds other than N2 is called Nr.
In fact, there is a small amount of Nr in the
air as well. Let’s say, if we collect only N2 froma balloon with a diameter of 1 m, the diameterof N2 would be 92 cm. If we collect only Nr, thediameter would only be about 0.7 cm. Livingorganisms want this small amount of Nr. And
this tiny existence of Nr controls the material
cycling in ecosystems.
Abe●The word “cycling” reminds me of theSpecial feature 1

This interview was conducted in June 2022. The statements made by bothparties are based on the findings at the time of the interview and thesituations in Japan and overseas. As one year has passed since the full-scalelaunch of the project at the time of this publication in August 2023, theproject activities have become more concrete and some events may differ
from the views expressed at the time of the interview, they have been
included to respect the documentary nature of the interview.

radar chart of the Planetary Boundaries (Fig. 1),
and the “N cycling” out of the nine subsystems
far transgresses its boundary.
Hayashi●The thing is, this radar chart shows
only one aspect of N. It’s shown as an indicator
to prevent eutrophication in shallow coastal
areas. It’s calculated using numerical models on
a global scale and shows the acceptable level ofthe anthropogenic N loading and then, sends
an alert to humanity because the actual load ismuch higher than that, telling all of us, “this isdangerous.”
Abe●That means it’s not referring to the whole
N cycling, then.

Biosphere integrity

Climate change

How much of ecosystem functions aremaintained andRate of extinction
the extension rate of species
Loss of ecosystem

CO2 concentration in the atmosphere andenergy balance between the Earth and spacefunctions(not assessed)

Novel entities

Land-system change

Including pollution by chemicalcompounds such as plastics

The size of forest areas

Freshwater change

Freshwater use (Blue water)

Stratospheric ozone depletion

The amount of freshwater available
for human use and the amountof water taken up by plants
Green water

Reactive N (Nr) lurking behindenvironmental issues
Hayashi●There are various forms of Nr, the most
known of which is nitrous oxide (N2O) as agreenhouse gas.
Actually, N2O has a greenhouse effect about
300 times greater than carbon dioxide (CO2)of the same weight. Although the atmosphericlevels of CO2 are much higher, N2O is also an
important greenhouse gas, and destroys ozone
in the stratosphere.
Abe●Not only chlorofluorocarbons (CFCs) dothat...
Hayashi●While there has been considerable
progress in eliminating CFCs, N2O emissions
continue to increase. It is recognized thatN2O is now the largest contributor of thestratospheric ozone depletion.
Abe●People really don’t know that.
Hayashi●It’s already common knowledge
among experts, so we don’t have to venture tomention it. According to the radar chart of thePlanetary Boundaries, the stratospheric ozone
depletion is settling down compared to theother eight problems and has subsided within
the safe range. In terms of N2O, I feel it’s betterto give priority to the climate change issue.
Abe●Is there anything else related to N that weshould particularly take notice of?
Hayashi●I mentioned earlier that there is only
a tiny amount of Nr in the air, but this “tiny”
is the key here. For example, it’s associatedwith aerosols, particularly fine particulatematter called PM2.5 defined as particles ofless than 2.5 ㎛ in diameter. PM2.5 is so smallthat you can inhale it and it can go deep into

For the most up-to-date
information on thisproject activities, please
visit their website.

Stratospheric ozone concentration

Phosphorus (P)Biogeochemical flows
The amount of runoff to oceans andsoils of synthetic N and P fertilizers

Atmospheric aerosol loading
The amount of air pollutants (not assessed)

Nitrogen (N)Ocean acidification
Carbonate ion concentrationin oceans

Below the boundary …Safe
Unstable zone …Increasing risk
Overshoot …High risk

Figure 1: The Planetary Boundaries’update status
The Planetary Boundaries concept proposes a set of nine planetary boundaries that humanity must
not exceed to survive sustainably on the Earth and illustrates its update status in the radar chart format.
In Japanese, it’s called “Chikyu no genkai (limits of the Earth).” A team led by Dr. Johan Rockström, anenvironmental scientist from Sweden, first announced this concept in 2009, and it has been updated several
times. This chart is based on data published in 2015.
Source: Azote for Stockholm Resilience Centre, based on analysis in Wang-Erlandsson et al 2022

your respiratory system, causing respiratory
diseases. Nitrogen is a significant componentof these particles. Specifically, fine particles
of nitrate and ammonium account for a large
percentage of the chemical composition of
PM2.5, as some papers even indicate that itcomposes as much as 40%. Therefore, N isalso associated with the “atmospheric aerosol
loading” in the Planetary Boundaries. In thevery beginning, I mentioned that “the N issue isdifficult to understand,” but if you look beneathvarious environmental issues, you will find that
N is lurking behind almost every issue. But
since we can’t see it on the surface, it becomesdifficult to understand its impact. We eat tosurvive, and we don’t even think twice to use
N as fertilizer for food production. However,it’s not well known that N is behind manyenvironmental issues.

Microorganisms driving
the natural N cycling
Abe ●Though N is not visible to our eyes, it isassociated with pretty much everything. Now
we understand that, but what about “cycling”?
For example, what about the cycling between
Nr and N2?
Hayashi ●Microbes were originally driving the
N cycling. Some microbes can convert N2 into
ammonia (NH3), and this process is called“biological N fixation.”
Abe●I have heard, for example, root-nodule
bacteria of legumes have such ability…
Hayashi●Some live symbiotically with legumes
while others are free-living microbes. Bluegreen algae or cyanobacteria are probably thebest known. Many microbes have this ability.
They are scattered over a wide area, and eachslowly and independently produce NH3 from

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Special feature 1

Behind the scenes:Talk with RIHN project leaders

Nitrogen is“everywhere” andwe cannot see why it’s important

N2, which is then converted into amino acids
for plants to use. This is the start of the N
cycling in ecosystems.
On the other hand, there is a process called“denitrification,” in which nitrite and nitrate inecosystems are reduced to N2. This is also an
important microbial function.
Abe●Do these microbes perform both
functions?
Hayashi●They are carried out by different
microbes. The cycling works out as they bothare present in ecosystems. Otherwise, if only
fixation process is done, Nr will continue toaccumulate. If only denitrification is done,
nutrients will be lost. Since there are microbesthat fix N into Nr and other microbes that
reduce Nr into N2, the N cycling is balanced.
And, plants and animals exist in between, andthey utilize the nutrients successfully.
For exa mple, N-f i x i ng
microbes initially use the fixed
N to build their bodies, in otherwords, organic compound.
W hen they die, they aredecomposed into ammonium,
which are quickly absorbed byplants to grow their bodies. If
there are animals present, theyeat plants and grow, and animals
also have the predator-prey Ken-ichi Abe
relationship. When plants andanimals die, microbes decompose their bodies
and circulate again. In the final stage of such
N cycling, some microbes turn Nr into N2 andreturn it to the atmosphere, and they are called“denitrifying microbes.”
Abe●I don’t think I’ve heard much about them.
Hayashi● I think our field is the only one thatuses these terms (laughs).
Abe●However, they play a very important role.
Hayashi●Yes, exactly. The term “decomposer”
is often used, but the role of decomposers inecosystems is often discussed in the context
of the carbon (C) cycling of returning organic
matter into CO2.
Abe●We learn about the C cycling as themechanism of photosynthesis, don't we?
Hayashi●Carbon and N are actually associatedwith each other. This is because organic
matter is composed of C, N, hydrogen, oxygen,
phosphorus (P) and some other elements, so C

4alone cannot circulate on its own.
Abe●So, N plays an important role behind the
C cycling.
Hayashi●It’s not actually “behind,” but it rather
controls the whole process. It looks like C isdoing the work, but it’s N and P that are
essentially controlling the C cycling.
There is a book entitled “Eat Like theAnimals” written by a nutritional ecologist andan entomologist at the University of Sydney. A
Japanese translation of the book is available
with the title “Kagakusha-tachi ga kataru
shokuyoku (Scientists Talk about Appetite).”They says that all living things eat because
these things want protein. That was true
when they first researched insects. Then theylooked at larger animals, and it was all thesame. Finally, it was also found the same when
they looked at human beings. In sum, the factthat we all eat to have proteinmeans that we want N.
Abe● Our staple food today
is carbohydrates, but somepeople believe that our healthproblems began when we
started eating carbohydrates.
Prof. Taro Yamauchi of RIHN
Sanitation Project (*1) also said,“the problem is that rice is tootasty”(laughs).
Hayashi●That would be true
(laughs). I read in a book by Shinya Nishimaru,
a food ecologist that we should never bring
Japanese rice to Papua New Guinea when
doing field research. He said that people who
had been eating taro and yam would be in somuch trouble if they experienced and learned
the taste of rice (laughs).
Abe●As far as I remember, his research field
was also Papua New Guinea and the Solomon
Islands.
Hayashi●Rice also contains about 6% protein.
When Japanese people had rice as the mainpart of their diet in the past, they would eat
about 3 or 4 go’s (about 330 g per go) of cookedrice at a time. Rice was also a source of protein.
Abe●It is different now, isn't it? Does wheat
contain less protein than rice?
*1 The RIHN Research Project “theSanitation Value Chain: Designing
Sanitation Systems as Eco Community-Value System” which
was completed in FY2021.

Humanity & Nature Newsletter No.89 August 2023

↑ Download from here.

This brochure was developed as part of the
project’s activities to provide an overview of theN issue to various stakeholders and to inspire free
discussion. Both Japanese and English versions
area available for download on the project website.

Hayashi●It does contain a certain amount suchas gluten.
Abe●An old classmate of mine who joined theMAFF was searching for effective genes tobring the protein level of wheat up to that ofrice. He patiently studied about 4,000 varietiesof wheat and finally found it after the 3,000
varieties. I was amazed with his patience(laughs).
Hayashi●Thremmatologists always have to takethat way (laughs).

The Haber-Bosch processthat changed the balanceof natural N cycling
Abe●We are getting sidetracked, so let us getback to “cycling.” The problem is that the N
cycling is now greatly distorted, isn’t it?
Hayashi●As I mentioned earlier, the balance innatural ecosystems used to be maintained bysome microbes that fixed N2 into Nr, while
denitrifying microbes turned it back to N2.
Then, once humanity came into the picture,they gradually created the “anthroposphere”
within the “biosphere.”

Alchemy of “making bread from air”
Hayashi●It’s obvious that as the population
grows, the demand for food increases. Food
harvested from the natural world could nolonger feed the increasing population. ThereSpecial feature 1

are several strategies to overcome this problem,
one of which is to increase the area of farmland.
But there is a limit, of course. Then, the next
possible option is to use fertilizer to increase
the production per area, i.e., yield.
Historically, livestock waste and, of course,
human waste were used as fertilizer. However,as a matter of course, this was done by simply
returning what people and livestock had eaten
to land, so if there was not enough food to eat,
the availability of such the organic fertilizer
also decreased. This means that we need otherforms of fertilizer. That is why humans havebeen searching for materials for fertilizer for avery long time.
Then, what happened was the discovery
of guano and Chilean nitrate. Guano is theaccumulated excrement and carcasses ofseabirds on the islands off the coast of Peru.
Chilean nitrate can be found in the Atacama
Desert, which straddles Peru, Bolivia, andChile. The area used to be an ocean, but it has

dried up due to uplift. Nutrient salts that had
accumulated in the ocean spread out with lowgrade contents. People rake this layer to collectnitrate salts.
But these fossil N will be eventually gone ifthey keep digging up. Guano has been alreadygone. Chilean nitrate is still available, but notefficient because of its low-grade content in thedesert soils.
Just before the turn of the 20th century, Sir
William Crookes (*2) said during his speech at
the British Association for the Advancementof Science, that if things continue as they are,humanity will starve in the near future, and theonly way to avoid this is to artificially produce
N fertilizer. By that time, it was known thatabundant N2 existed in the atmosphere, so thecompetition in technological development for
artificial N fixation began.
Abe●It is like alchemy, isn’t it?
Hayashi●Alchemy, yes exactly. As you all know,
it’s “the Haber-Bosch process.”
Abe●So, the “unusable N” in the atmospherecan be....... something like that can be done.
Hayashi●When Fritz Haber was working on
this research, people made fun of him, saying
it was a “technology for making bread fromair.” Precisely speaking, it’s “making fertilizer
from air, growing wheat with the fertilizer,
and making bread with the wheat,” but he wascalled “a strange person who is trying to makebread from air,” skipping over the in-between
steps.
However, he succeeded in synthesizing
NH3 from N2 and hydrogen on a bench scale.
And Carl Bosch, who was an engineer at alarge German chemical company called BASF,
which still exists today, bought out Harber’s
research achievement. He, then, took thelaboratory recipe and brought it to a level where
it could be industrially produced. That was in
the early 20th century.
Abe●This is truly a revolutionary innovation.
Hayashi●Absolutely, and there is plenty of
N2 around us, which is the ingredient forthis process. All we need now is hydrogen.
There are various techniques for this, suchas electrolysis of water or extracting only
*2 Sir William Crookes (17 June 1832 - 4 April 1919)
was a British chemist and physicist. He is known
for his discovery of the element thallium andworks on cathode rays and became president of
the Royal Society in 1913.

hydrogen from coal and natural gas. Then, we
can produce fertilizer.
Abe●An energy source is obviously necessary,right?
Hayashi●Right. Back in those days, the energy
source was mostly fossil fuel combustion. You
would have to go to an island in South America
to harvest guano, but the NH3 production
using the Haber-Bosch process made it possible
to produce fertilizer anywhere in the world
as long as hydrogen and N2 were available
together with an input of energy.

Fertilizer in peacetime,
gunpowder in wartime
Hayashi●I’m sidetracking again, but there isa reason why the Haber-Bosch process wasdeveloped in Germany. Germany at thattime was already in a state of quasi-war, or
rather, a state close to conflict with Britain,
and Germany needed fertilizer to feed its own
people. In addition, the negative side of N is that
N can also be used as gunpowder.
Abe●Oh well, whether you think of it as
negative or positive is.......
Hayashi●I feel that they rather prioritized that
aspect. Potassium nitrate as an Nr species
can be used as explosives. Nitroglycerin is
too unstable to use as it is, so it was soaked indiatomaceous earth and fused to make it stableenough to use. Since it was Nobel who invented

National Institutes for the Humanities ● The Research Institute for Humanity and Nature5

Special feature 1

Behind the scenes:Talk with RIHN project leaders

Nitrogen is“everywhere” andwe cannot see why it’s important

this dynamite, we can see that the Nobel Prizealso has a deep connection with N.
Because of the British blockade of the sea,
Germany could no longer import Chilean
nitrate, leaving them with no means to produce
fertilizer and gunpowder. They had to dosomething to produce on their own, so they
stepped up efforts toward developing N-fixing
technology.
Abe●That’s why it started in Germany.
Hayashi● I don’t think that was necessarily the
only reason, but many competing researchers
were also from Germany. Wilhelm Ostwald,
who invented a process for manufacturingnitric acid, and Walter Nernst, who worked onthermodynamics, all received Nobel Prizes inchemistry. Germany in those days was terrific.

Nr leaking out of
the anthroposphere
Abe ●The Haber-Bosch process i s arevolutionary technology with its almost
unlimited materials.
Hayashi●You can produce as much as you want,
and the more fertilizers you put on farmland,
the more yields you can get. But then, theproduction of fertilizers alone would not beenough, so we need to develop new varietiesthat can yield more responding to the increased
fertilizer application rate, invent agrochemicals
such as pesticides and herbicides, andmechanize farm equipment….
The Green Revolution was the result ofdeveloping all these things. It’s around 1950s
and 60s after the World War II, when the
consumption of N via the Haber-Bosch process
began to increase rapidly, and it continues to do
so today.
Abe●The problem is that it continues toincrease.
Hayashi●When we produce a large amountof synthetic fertilizer and we keep its cycling
within the anthroposphere, there is notmuch of a problem. Unfortunately, however,a significant portion is leaking out. There arevarious estimates, but roughly speaking, 80% of
input N does leak out.
Abe●You mean, for example, into farmland?
Hayashi●Not only for agricultural use, but when
we burn fossil fuels for energy conversion,
it would produce nitrogen oxides and other6

substances being emitted to the atmosphere. Of
course, we have the technology for wastewaterand exhaust gas treatment, which allows us
to convert a significant portion of Nr back toharmless N2. But that involves a cost. Andenergy and materials are needed for suchtreatment. The remaining Nr is lost to theenvironment and causes issues such as global
warming, eutrophication, and air pollution.
Abe●So today, the amount of Nr that cannot beprocessed by the microbes on the earth.......
Hayashi●Not converted back to N2 and leaks out.
Abe●Then, it’s causing all kinds of problems.
In the Planetary Boundaries, thresholds
are set for the biochemical flows of P as well
as N. Phosphorus production still depends
on mineral phosphate because there is nomanmade alchemy like the Haber-Boschprocess.
Hayashi●The only means we currently have is tocollect it from where densely concentrated.
Abe●For P, the solution is quite easy tounderstand. However, in the case of N,
there are various forms of N, and it’s also
quantitatively massive.
How can we find a solution to this issue, which
is never easy?
Now let’s talk about your project.

How to deal with
the N issue closely related
to our dietHayashi●80% of our N use is for fertilizer. That
is why food production is so important here.
But this is two sides of the same coin. Japan
imports a large portion of its food and feed, so
more than half of N use in Japan is actually forindustrial purposes.
Abe●For industrial purposes?
Hayashi●An easy example is production ofchemical fibers and plastics such as nylon andurethane. We do use quite a lot of N for suchindustrial production. However, on a global
scale, 80% of the N created by the Haber-Boschprocess is used for agricultural purposes.
Abe●So, if we could do something about this
80% of N use for agricultural purposes, would
you say that the N cycling would improveconsiderably?
Hayashi●Yes. The Haber-Bosch process, which

Humanity & Nature Newsletter No.89 August 2023

was invented 110 years ago, is an entry pointof the current N cycling. A significant portionof the N used for food production leaks to theenvironment, so if we can improve its N use
efficiency (NUE, here the ratio of harvested N
to the total N input), we can definitely improve
the N cycling.

Looking at our diet throughthe lens of the NUE
Abe●Industry is a closed system while
agriculture is an open system. When you say
improving their NUE, do you mean preventing
N loss to the environment?
Hayashi●In short, yes. However, it’s notnecessarily only about improving the NUE of
agriculture, but it also involves “what we eat.”
Abe●So, you mean we have to think not only
about agriculture but also our diet?
Hayashi●Yes. The crop production NUE in
the world is roughly 50%, but with livestock
production, its NUE downs to 5% to 20%

Special feature 1

N pollution

Fossil fuelN2
Natural gas
H source

Climate change

N wasteStratospheric O3 depletion
ExhaustNH3 Synthesis→Nr transformation

Nr

Energyconversion

Treatment

Loss to theenvironment

N2 ：Dinitrogen
NH3 ：Ammonia
Nr ：Reactive Nitorogen(Compounds other than N2)

Air polluthion
Water pollution

loss and waste

N2

Fuel NH3（new）

Eutrophication
Acidification

Fertilizer/Material

Food/Goods
Benefit of N use

Harmless

EnergyHealth impact

Trade off
(N issue)

Ecosystem impact

Threat of N pollution

Fig. 2: Tradeoff between the benefits of nitrogen (N) use
and the threats due N pollution (N issue)
The Haber-Bosch process, the invention of the artificial synthesis technology for ammonia, made it possible
to produce as much reactive (Nr) as desired, and Nr provides great benefits to humanity as fertilizer for foodproduction and materials for industrial production. On the other hand, most of the Nr used by humans is lost as
the reactive Nr to the environment. Nitrogen use efficiency is low in the food production process, but food loss
is another major factor. The Nr emission causes various types of nitrogen pollution, and damages to ecosystem
health. The tradeoff between the benefits of N use and the threats due to N pollution is called the “N issue.”depending on farming styles and species.
Livestock nowadays are sometimes fattened on
grain that humans can eat, so it’s no surprisethat the livestock production NUE would
naturally drop. Livestock are animals, andobviously not everything they are fed turns into
meat. They repeat eating and excreting to growbigger and produce meat or eggs, so the NUE isinevitably lower.
Therefore, the NUE varies greatly dependingon, for example, whether you eat plant-based
protein such as soybeans or meat to have thesame amount of protein.
Abe●Tofu is better than meat.
Hayashi●I mean it’s better than meat, butsoybeans also have its own problems if welook closely... It also involves the aspect of foodculture and the freedom to choose what to eat.
But at the very least, I would like everyone toimagine how eating something will affect theenvironment.
When eating meat, beef or pork, for example,
you should better know how cows and pigs
live and walk. We should think about where
and how the food we are going to eat camefrom. We tend to look at food traceability often
from the perspective of consumer safety andsecurity, but it’s also related to environmental
issues. If we better understand how “eating” isassociated with the environment, we will be
more conscious of the food we eat, which will

hopefully lead to reducing food loss.

Thinking about environmental
issues through food
Abe● I understand that two of your project
members are from Tsuji Culinary Institute.
Hayashi●Our project wants chefs, in otherwords, people who work with food, to havecorrect knowledge of the environment.
Green jobs refer to jobs that contribute toenvironmental conservation and sustainability
while fulfilling the requirements for “decent
job.” I believe that our project can contributeto making more opportunities for them tocreate new green jobs. Rather than blindly
thinking that this might be a good way, I expectthat they will be well equipped with basic
knowledge of environmental issues, have goodunderstanding of “this will have this kind ofeffect,” and expand the horizons of new ideas.
Recently, I’ve been having more and more
opportunities to talk about N at high schools,
and the students have been very receptive,
writing in their post survey forms that “it wasinteresting to learn.” I think, if I continue to do
this process one step at a time, more and more
people can learn about the N issue. I especiallywould like junior high and high school students
to learn about this.
Abe●RIHN and the Kyoto Prefectural Boardof Education have signed a Memorandum ofUnderstanding (*3) to collaboratively develop
environmental education and researchmethods. I teach environmental education
classes at Kyoto Prefectural Rakuhoku HighSchool, a Super-Science-Highschool locatednear RIHN.
We also have an agreement on academic
exchange with Miyazaki Prefecture. Miyazaki
Omiya High School, one of the leading schools
in Miyazaki Prefecture, has been selected for
the Super Global High School (*4) and World
Wide Learning (*5) projects promoted by the
Ministry of Education, Culture, Sports, Scienceand Technology, and they are developing
new recipes that make the most of local foodproducts, and distributing to the world.
Hayashi●That sounds very compatible with our
project. I would love to speak at the high school
about how food is deeply connected to theenvironment.
Abe●Food is more than just being “tasty.”
Hayashi●Another food-related idea our project isworking on is to create opportunities for people
to feel the connection between food items andnature through the lens of food. Japanese dietcould have both traditional Japanese food andthe neo-Japanesque food that will be newly
created in the future, but Japanese diet makes
it possible for us to properly enjoy change ofseasons and connection with living things.
In Japan, we have “shun (top season)” formany food items. Not only we can savor
seasonal food, thinking “they are tasty because*3 Signed in June 2022. This MOU aims at promoting
the collaborative implementation of environmental
education, and research development in Kyoto by
RIHN researchers giving on-site classes at schools,
giving trainings to teachers, and helping createteaching materials, while RIHN will utilize firsthandfeedback from the field of education in its research
activities and the creation of educational programs,
etc.

*4 The program aims to nurture future global
leaders who can play an international andactive role and promotes the collaboration withboth Japanese and international universities,
companies and international organizations toengage in cross-sectional, comprehensive, andexploratory learning on global social issues andbusiness issues.
*5 The Support Project for Building the World
Wide Learning Consortium. With the aim ofdeveloping innovative global human resources,
the consortium will collaborate with universities,
companies and international organizations inJapan and abroad to research, develop, andimplement advanced curricula.

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Special feature 1

Behind the scenes: Talk with RIHN project leaders

Nitrogen is“everywhere” andwe cannot see why it’s importantthey are in season,” we can also appreciate eachseason, thinking “the season is passing by”
while eating them. It's just like saying, “see you
again next year.”Food is not just nutrition, but through eating,
we can understand that food items are also
living things, and that these living things areconnected to nature and to a vivid sense of
the season. Our project hopes to increase
opportunities for people to understand byseeing with their eyes, smelling with theirnoses, and tasting with their palates, not justby words.

Knowing and sharing
the current situation in
Japan and discussing“the futurability” together
Abe●In Japan, the major use of N is forindustrial purposes, but does this mean thatthe mode of N cycling differs completely fromregion to region?
Hayashi●Yes, there are tremendous differences.
Abe●How does your project consider suchregional variations? I think some regions
thoroughly use fertilizers in agriculture, andI would like to know about such regional
differences. ...... When you first told us about
the concept of your project, you talked about“the N cycling on a global scale,” I think…

Outsourcing the responsibility ofN pollution to other countries
Hayashi●I would like to separate the frameworkof this project and the N issue in general.
First, this project will focus on Japan.
There are reasons for this: Japan imports not
only various products but also a significant
amount of fossil fuels, which contain a lot of N
in total, all of which would be released to theatmosphere when combusted. I explain in oneof my papers that significantly more N comesfrom fossil fuels than fertilizers in the case ofJapan.
Of course, we also import a huge amount offood and feed. This means that we are making
the countries of production responsible for N
pollution during production. N pollution is
occurring at the production sites, but we are
only paying for the final products. In the future,8

when we import products, we may need tocompensate the cost of countermeasures forsuch environmental impacts. Japan would not
like to see that happen.
However, I would say that Japan is just too
unaware of this fact. Looking at the state quoof consumption in Japan, I believe that we aresomewhat on the way out of mass production
and mass consumption, but the way we handle
food is recklessly inefficient.
The annual amount of Japan’s food loss is 7
million tons. Japan’s rice production is 8 million
tons, so it’s about the same. The UN World
Food Program (WFP) provides about 4 million
tons of food aid, so Japan, just one country,
is throwing away nearly twice that amount.
I believe that we had better first learn about
this. While our project is researching on the N
cycling, we are also trying to raise awarenessabout food through N.

Ecosystem restoration, a hard task
Hayashi●On the other hand, if we look outsideof Japan, there are areas in trouble without
sufficient N in the soil. Sub-Saharan Africa (theregion south of the Sahara Desert) is a typicalexample. They are economically distressed, sothey cannot afford fertilizer. But the population
is so large that they have to find a way tosomehow feed people, so they are simply forced
to continue farming, no matter what.
What happens when they continue like thisis that the organic matter stored in the soil
decreases gradually, and the land becomesless and less fertile. Once the soil becomes too
depleted, no matter how much fertilizer andwater are applied, it cannot hold and absorb
them and they would runoff.
Abe ● This is exactly what Prof. Shuichi
Oyama of the Organic Material Circulation
Project (*6) is doing in the Sub-Sahara, puttingorganic waste collected in urban areas into
farmland for greening. This is still at the
beginning stage. ......
What about Japan? For example, the Seto
Inland Sea in Japan is currently, in fact, facing*6 The RIHN Research Projectthat started in FY2022 as PreResearch: “Building up organic
material circulation system among
urban and rural area: Toward theintegration of local perception andscientific knowledge.”

Humanity & Nature Newsletter No.89 August 2023

oligotrophication.
When the Seto Inland Sea experienced
eutrophication in the past, I thought Japanwas quite competent since the government
controlled the total inflow of N and P. I comefrom a fisherman family, and they were talking
about how the catch was decreasing during thattime.
Professor Emeritus Tamiji Yamamoto at
Hiroshima University, for example, is one ofthose with the idea of “using the Seto Inland
Sea as garden or field.” He also argues that what
the Seto Inland Sea needs now may be N and P.
Hayashi●That’s quite possible.
Abe●Even within Japan, the nutritional statusvaries from region to region and from site tosite.
Hayashi●Absolutely correct. I think there
are regional variations. We know of theoligotrophication of the Seto Inland Sea, butthat is also the case in some parts of Lake Biwa
and Lake Suwa.
To be honest, I don’t think the expression“oligotrophication” is necessarily correct. I
think, if we look at what is exactly happening

Special feature 1

While N provides great benefits to humanity as fertilizer for food production, materials for industrial production, fuel among others, it also causes N pollution to theenvironment and poses a wide range of threats such as climate change, stratospheric ozone depletion, air pollution, water pollution, eutrophication, and acidification. The
brochure introduces the status of the N cycle with easy-to-understand illustrations.

there, a different term would be more suitableto describe the situation.
A red tide or blue tide occurs in the processof eutrophication, resulting in large-scale deathof living things. This could result in the loss of
key species and/or a decrease in biomass in theecosystem. In such situation, the improvementof water quality alone wouldn’t be able torestore the ecosystem to its original statebecause the key players are no longer present.
We call this “oligotrophication.”
Abe●If that is the case, could we just put N and
P in the Seto Inland Sea, just like we apply N
chemical fertilizers to farmland?
Hayashi●We cannot undo the changes
immediately. It would be difficult unless
we return the key species that were there
originally.
Abe●In Lake Biwa, several RIHN projects
were doing work. Prof. Noboru Okuda’s e-rec
Project (*7) strongly focused on involving the
local communities in the watershed, which
led to the successful establishment of human

network. This is what we can call an asset of
RIHN, and I think you can leverage this foryour project as well.

We can’t resolve the issue unless
we see the entire picture
Abe●When I first heard your project concept
at one of RIHN’s meetings, I thought, “they’regoing to do everything!”
Hayashi●Yes, we’re doing (laughs).
Abe●After talking with you today, I do
understand why.
Hayashi●It would be pointless when you control
something and end up having something else
overflow.
Abe●You think you are solving a problem, but
it’s like playing whack-a-mole.
Hayashi●If you know that “if you whack here,that will pop out,” you would probably try
pushing both a little.
*7 The RIHN Research Project“Biodiversity-driven Nutrient
Cycling and Human Well-beingin Social-Ecological Systems”
completed in FY2019.

Abe●The easiest way to get results is tosimplify the problem. It would be easier to see
the cause and effect in a linear relationship.
This may be just fine in respective fields,
but it will not resolve environmental issues.
Interdisciplinarity is required.
Hayashi●Agree. The integration of natural,social, and cultural sciences is important here.
Abe●We do have to look at the full picture of theN issue, which is complex and intertwined. But
at the same time, don’t we also have to think
about some sort of one-point breakthroughsolution?
Hayashi●Thank you for your importantquestion. I don't expect this project to address
everything optimistically, but at least I wantto make sure that people would know that
there was/is this project at RIHN with a clear
vision of “we can’t resolve the issue unless we
see the entire picture.” Then there will be thehope that the next generation of those withdetermination will develop it further in the
future. So, I want to be “a stone to be stepped

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Special feature 1

Behind the scenes: Talk with RIHN project leaders

Nitrogen is“everywhere” andwe cannot see why it’s important

Hayashi●An advantage of this project isgreat international connections that wehave. I’ve been a project member of the UN
Environment Programme’s (UNEP) program
called International Nitrogen Management
System (INMS) (*8). The UNEP holds the UN
Environment Assembly (UNEA) every two
years, where they will adopt the “Resolution on
Sustainable Nitrogen Management.”
However, the 5th UNEA in 2022 decided
to focus on the topic of microplastics in theocean, and consequently came up with very
important actions to take. The issue of N
management will probably be carried over tothe next assembly in 2024. We’re currently
discussing creating a framework for how eachmember nation can address the international N
management.
In response to this, I have proposed if our
project could collaborate, for example, in
communication such as the Future Design
approach. Of course, we hope to commit
our project to this international framework

scientifically, but we would also like to assist
people in each member nation to envision our
future.
Abe●Prof. Yoshinori Nakagawa is working on
RIHN Future Design project (*9).
Hayashi●The Future Design approach starts
with an assumption that, for example, we
become imaginary future persons living andeating happily in 2050 and think that “we arenow (2050) in this state because we made someactions in the past since 2020.” What I findinteresting is that different ideas would emerge
when we envision 2050 from the current
situation that we are in and when we generate
ideas based on what we did in the past (i.e., thepresent), immersing ourselves in pretending to
be living in 2050.
At the very least, if you look from both
perspectives, you will not suffer a loss. If
you look at the present from the future as
imaginary future persons and come up withinteresting ideas, it’s a lucky win; if not, that’s
what it was supposed to be anyways...... By
applying the Future Design approach, ourproject can contribute to bring new ideas tothe table.
Abe●I see, I think that is indeed a sort ofbreakthrough, or perhaps a way out.
When you introduced your project at one
of RIHN’s meetings, you mentioned thatyou were also thinking of contributing to theinternational N management led by UNEP, but
to be honest, I’m not sure what exactly UNEP
wants to do.
Hayashi●Yes, that's right. I think they’re still
discussing that.
Abe●If you can propose to incorporate theresearch results of your project and the Future
Design process into the discussion, and present
what should be done and what is important for
the future of N management, I do feel a sense ofhope that it will have a quite great impact.
Hayashi●I also have high hopes. I think it’s quitea challenge, though. Nitrogen experts alreadyhave a pretty good grasp of the issue, but inan organization as vast as UNEP, it is up to
the representatives of each member nation toregard the issue as their own.

*8 Scientists from around the world join to examine
the need for global N management and effective
management processes and investigate how
improving N use will expand benefits (completed inJune 2023).

*9 The RIHN Research Project“Development and Pluralis tic
Coexistence of Sustainability Visions
Through Future Design” started in
FR2022 as Full Research.

over” (laughs).
Abe●That’s too soon to say things like that! Your
project has only just started (laughs).
Hayashi●I think I will still be active for the time
being, but that’s what I am thinking about.
One of the important perspectives inenvironmental issues is when we take someaction, reactions will accompany. As you
pointed out, most of the measures taken forenvironmental issues to date have been a onepoint breakthrough solution. As a result, it
caused new problems in other areas. Therefore,
what I would like to emphasize here is that it’snecessary to have people with a broader vision.
Particularly, N is associated with almost allenvironmental issues, so if there is someone
with such a broad vision, for example, heor she can say to those who try to resolve
environmental issues with a one-point
breakthrough approach, “you have to be careful
because if you do that, you may encounter
other problems like this.”Envisioning future with
the Future Design10

Humanity & Nature Newsletter No.89 August 2023

Kentaro Hayashi (left)
He specializes in biogeochemistry, soil science,
and atmospheric science, and has a wide range ofinterests in biology, ecology, history, geography,
food culture, etc. In FY2016, he participated in the
58th Japanese Antarctic Research Expedition (JARE)
Summer Party. His main research interests arenitrogen cycling and sustainable use of nitrogen.
After working as a Senior Principal Scientist at theInstitute for Agro-Environmental Sciences, National
Agriculture and Food Research Organization (NARO),
he joined RIHN as a joint cross-appointment project
leader in 2022, and fully moved to RIHN in 2023.
Ken-ichi Abe
He is a Professor and Head of Communication Unit
Strategic Planning and Management Department at
RIHN. His expertise is environmental anthropology.
He has been a member of RIHN since 2008.

Humanity living toward
the future of good hope
Abe●When we look at a complex issue like N, it
is important to recognize the facts, of course,
but in the end, we must also ask about value
propositions, i.e., the question on how the issue
should be.
Hayashi●I believe that the facts and values are
all linked. How should we live? Or I should
probably say how we want to live.
When I say that we should return the N
cycling to how it used to be, everyone respondswith “why?” But the N cycling is directly
linked to our own life. If we can achieve thestate of “further wellbeing,” the N issue would
be resolved before we recognize it. In fact, I
sometimes wonder if such a solution would bebetter.
Envisioning the far future is one uniqueability of humanity, I would say. We can draw
a happy future and live toward it. Of course, theopposite is also possible, which is what I findscary about humanity.
Abe●It was a great talk today. Thank you verymuch.
June 15 (Wed), 2022: At the RIHN Courtyard
This interview was conducted in Japanese.
(Translated by Yuko Kobayashi)