New Scientist - USA (2021-11-06)

28 | New Scientist | 6 November 2021

Views Columnist

James Wong is a botanist

and science writer, with a

particular interest in food

crops, conservation and the

environment. Trained at the

Royal Botanic Gardens, Kew, he

shares his tiny London flat with

more than 500 houseplants.

You can follow him on Twitter

and Instagram @botanygeek

T

HE interconnectivity of our

world never fails to amaze

me. Even as a plant scientist

fascinated by food production, I

am often astonished by the extent

to which changes in a seemingly

unrelated industry on a distant

part of the planet can affect our

dinner plates – and the reaction

of pundits to these impacts.

Recently, news broke that

soaring global fertiliser costs,

created by factors such as rising

energy prices in China, would

be likely to have a devastating

knock-on effect on the food

security of some of the poorest

people on Earth.

Surprisingly, some activists and

thought leaders saw this price hike

as a good thing, because it would

provide a market mechanism

to force farmers to reduce their

“addiction” to fertilisers. According

to this narrative, fertiliser use has

gone “up and up”, and masked

a “terrifying and accelerating”

collapse in global soil health,

which is often worse for people

in low-income countries trying

to feed themselves. Given the

frequency and conviction with

which this view is expressed,

and the devastating impact it

could have, I thought I should

go in search of the facts.

So, the first thing we need to

acknowledge is that overuse of

fertiliser is a problem. It is well

established that run-off of excess

nutrients pollutes water courses,

with a destructive impact on the

environment. The extent of this

effect can be wide-ranging,

with farmland run-off in the

US Midwest contributing to

algal blooms in the Gulf of

Mexico hundreds, sometimes

thousands, of kilometres away.

That is before we talk about

the greenhouse gas emissions

produced in the manufacture of

fertiliser. Alone, the Haber-Bosch

process – which captures

atmospheric nitrogen and

converts it into a soluble form

that plants can more readily

use – produces roughly 1.4 per

cent of global carbon dioxide

emissions. That might sound like

a small amount until you compare

it with the emissions associated

with all of the aviation industry,

which are around 2 per cent.

I think we can all agree that

reducing our reliance on such

synthetic fertilisers would be a

good thing. But this is where it

starts to get complicated. Despite

frequent reports of ever-escalating

use of synthetic fertiliser, in fact,

in many Western countries,

it has markedly declined.

In the UK, for example, the

amount of fertiliser used per

hectare has fallen by about

20 per cent since the turn of

the millennium, and is now at

its lowest levels for more than

30 years. Many other European

countries, including the

Netherlands, Italy and Denmark,

have seen a similar trajectory,

as has Japan. Even when you

include some of the world’s

most important food-producing

countries such as the US, Russia

and Australia, you see a plateauing

of fertiliser use over the past

two decades, certainly not

the unstoppable upwards

trajectory that is often claimed.

What is true, however, is that

on a global level, there has been a

big increase in the use of fertilisers

in the same period, with a 32 per

cent rise recorded since 2002.

Even this, though, doesn’t really

show us the complete picture.

Fertiliser usage is traditionally

calculated by the weight used per

unit of land. Given that the whole

point of the exercise is to feed

people, would it not make more

sense to see these stats in the

context of global population

levels? After all, while global land

area hasn’t changed in the past

two decades, our population has

increased by around 27 per cent.

Use of synthetic fertiliser

broadly reflects an increase in the

number of mouths to feed. In fact,

some scientists have calculated

that since its widespread adoption

at the beginning of the 20th

century, it has been the only way

we have been able to support a

growing population. Two decades

ago, these fertilisers allowed us

to feed 43 per cent of humanity.

By 2015, that figure was estimated

to have increased to just under

half the world’s population.

Here is some more context:

today, as many as 811 million

people go hungry. In fact, after

decades of progress, the number

of people lacking access to

sufficient food is on the rise again,

growing by as many as 161 million

between 2019 and 2020 alone.

Severe food insecurity now

affects just under 1 in 10 people.

So, yes, we do need to reduce

our reliance on fertiliser use, and

many of the world’s advanced

economies have already taken

great strides to do that. However,

there is no solid evidence to

support the claim that fertiliser

use is dramatically rising,

particularly in the context

of countries like the UK. And,

crucially, taking into account the

human cost, the argument that

fertiliser price rises are in some

way beneficial to humanity is

one that can be made only with

the luxury of a full belly. ❚

“ In the UK, the

amount of fertiliser

used per hectare has

fallen by about

20 per cent since

the millennium”

Are we really addicted to fertiliser? Frequent reports decrying

our ever-increasing use of synthetic fertilisers don’t reflect reality

and fail to see the bigger picture, writes James Wong

#FactsMatter

This column appears

monthly. Up next week:

Chandra Prescod-Weinstein

What I’m reading

In an effort to create some

semblance of a work-life

balance, my reading has

been confined to pub

and restaurant menus.

What I’m watching

Am I the only person not

watching Squid Game? So

far this month, it has been

a Frasier marathon.

What I’m working on

I am finishing up making

a global farming series

for the BBC as I type.

James’s week