you're buying some groceries,

and you get given the option

for a plastic or a paper shopping bag.

Which one do you choose if you want to do

the right thing by the environment?

Most people do pick the paper.

Okay, let's think of why.

It's brown to start with.

Therefore, it must be good for the environment.

It's biodegradable. It's reusable.

In some cases, it's recyclable.

So when people are looking at the plastic bag,

it's likely they're thinking of something like this,

which we all know is absolutely terrible,

and we should be avoiding at all expenses

these kinds of environmental damages.

But people are often not thinking

of something like this,

which is the other end of the spectrum.

When we produce materials,

we need to extract them from the environment,

and we need a whole bunch of environmental impacts.

You see, what happens is, when we need

to make complex choices,

us humans like really simple solutions,

and so we often ask for simple solutions.

And I work in design.

I advise designers

and innovators around sustainability,

and everyone always says to me, "Oh Leyla,

I just want the eco-materials."

And I say, "Well, that's very complex,

and we'll have to spend four hours talking about

what exactly an eco-material means,

because everything at some point

comes from nature,

and it's how you use the material

that dictates the environmental impact.

So what happens is, we have to rely

on some sort of intuitive framework

when we make decisions.

So I like to call that intuitive framework

our environmental folklore.

It's either the little voice at the back of your head,

or it's that gut feeling you get

when you've done the right thing,

so when you've picked the paper bag

or when you've bought a fuel-efficient car.

And environmental folklore is a really important thing

because we're trying to do the right thing.

But how do we know if we're actually

reducing the net environmental impacts

that our actions as individuals and as professionals

and as a society are actually having

on the natural environment?

So the thing about environmental folklore is

it tends to be based on our experiences,

the things we've heard from other people.

It doesn't tend to be based on any scientific framework.

And this is really hard, because we live

in incredibly complex systems.

We have the human systems

of how we communicate and interrelate

and have our whole constructed society,

We have the industrial systems, which is essentially the entire economy,

and then all of that has to operate

within the biggest system,

and, I would argue, the most important,

the ecosystem.

And you see, the choices that we make

as an individual,

but the choices that we make

in every single job that we have,

no matter how high or low you are in the pecking order,

has an impact on all of these systems.

And the thing is that we have to find ways

if we're actually going to address sustainability

of interlocking those complex systems

and making better choices that result

in net environmental gains.

What we need to do is we need to learn

to do more with less.

We have an increasing population,

and everybody likes their mobile phones,

especially in this situation here.

So we need to find innovative ways of solving some of these problems that we face.

And that's where this process called life cycle thinking comes in.

So essentially, everything that is created

goes through a series of life cycle stages,

and we use this scientific process

called life cycle assessment,

or in America, you guys say life cycle analysis,

in order to have a clearer picture of how

everything that we do in the technical part of those systems

affects the natural environment.

So we go all the way back

to the extraction of raw materials,

and then we look at manufacturing,

we look at packaging and transportation,

use, and end of life,

and at every single one of these stages,

the things that we do

have an interaction with the natural environment,

and we can monitor how that interaction

is actually affecting the systems and services

that make life on Earth possible.

And through doing this,

we've learned some absolutely fascinating things.

And we've busted a bunch of myths.

So to start with, there's a word that's used a lot.

It's used a lot in marketing,

and it's used a lot, I think, in our conversation

when we're talking about sustainability,

and that's the word biodegradability.

Now biodegradability is a material property;

it is not a definition of environmental benefits.

Allow me to explain.

When something natural,

something that's made from a cellulose fiber

like a piece of bread, even, or any food waste,

or even a piece of paper,

when something natural ends up

in the natural environment, it degrades normally.

Its little carbon molecules that it stored up

as it was growing are naturally released

back into the atmosphere as carbon dioxide,

but this is a net situation.

Most natural things

don't actually end up in nature.

Most of the things, the waste that we produce, end up in landfill.

Landfill is a different environment.

In landfill, those same carbon molecules

degrade in a different way,

because a landfill is anaerobic.

It's got no oxygen. It's tightly compacted and hot.

Those same molecules, they become methane,

and methane is a 25 times more potent

greenhouse gas than carbon dioxide.

So our old lettuces and products

that we have thrown out that are made

out of biodegradable materials,

if they end up in landfill,

contribute to climate change.

You see, there are facilities now

that can actually capture that methane

and generate power,

displacing the need for fossil fuel power,

but we need to be smart about this.

We need to identify how we can start to leverage

these types of things that are already happening

and start to design systems and services

that alleviate these problems.

Because right now, what people do is they turn around and they say,

"Let's ban plastic bags. We'll give people paper

because that is better for the environment."

But if you're throwing it in the bin,

and your local landfill facility

is just a normal one,

then we're having what's called a double negative.

I'm a product designer by trade.

I then did social science.

And so I'm absolutely fascinated

by consumer goods and how the consumer goods

that we have kind of become immune to

that fill our lives

have an impact on the natural environment.

And these guys are, like, serial offenders,

and I'm pretty sure everyone in this room

has a refrigerator.

Now America has this amazing ability

to keep growing refrigerators.

In the last few years, they've grown one cubic foot

on average, the standard size

of a refrigerator.

And the problem is, they're so big now,

it's easier for us to buy more food

that we can't eat or find.

I mean, I have things at the back of my refrigerator

that have been there for years, all right?

And so what happens is, we waste more food.

And as I was just explaining, food waste is a problem.

In fact, here in the U.S., 40 percent

of food purchased for the home is wasted.

Half of the world's produced food is wasted.

That's the latest U.N. stats. Up to half of the food.

It's insane. It's 1.3 billion tons of food per annum.

And I blame it on the refrigerator,

well, especially in Western cultures,

because it makes it easier.

I mean, there's a lot of complex systems going on here.

I don't want to make it so simplistic.

But the refrigerator is a serious contributor to this,

and one of the features of it

is the crisper drawer.

You all got crisper drawers?

The drawer that you put your lettuces in?

Lettuces have a habit of going soggy

in the crisper drawers, don't they?

Yeah? Soggy lettuces?

In the U.K., this is such a problem

that there was a government report a few years ago

that actually said the second biggest offender

of wasted food in the U.K. is the soggy lettuce.

It was called the Soggy Lettuce Report.

Okay? So this is a problem, people.

These poor little lettuces are getting thrown out

left, right and center because the crisper drawers

are not designed to actually keep things crisp.

Okay. You need a tight environment.

You need, like, an airless environment

to prevent the degrading that would happen naturally.

But the crisper drawers, they're just a drawer

with a slightly better seal.

Anyway, I'm clearly obsessed.

Don't ever invite me over because I'll just start going through your refrigerator

and looking at all sorts of things like that.

But essentially, this is a big problem.

Because when we lose something like the lettuce from the system,

not only do we have that impact I just explained at the end of life,

but we actually have had to grow that lettuce.

The life cycle impact of that lettuce is astronomical.

We've had to clear land.

We've had to plant seeds, phosphorus,

fertilizers, nutrients, water, sunlight.

All of the embodied impacts in that lettuce

get lost from the system,

which makes it a far bigger environmental impact

than the loss of the energy from the fridge.

So we need to design things like this far better

if we're going to start addressing serious environmental problems.

We could start with the crisper drawer and the size.

For those of you in the room who do design fridges,

that would be great.

The problem is, imagine if we

actually started to reconsider how we designed things.

So I look at the refrigerator as a sign of modernity,

but we actually haven't really changed the design

of them that much since the 1950s.

A little bit, but essentially they're still big boxes,

cold boxes that we store stuff in.

So imagine if we actually really started

to identify these problems and use that

as the foundation for finding innovative and elegant

design solutions that will solve those problems.

This is design-led system change,

design dictating the way in which the system

can be far more sustainable.

Forty percent food waste is a major problem.

Imagine if we designed fridges that halved that.

Another item that I find fascinating