5. How much clean electricity do we really need (subtitles)

00:16

Hello, how is everyone feeling?

00:18

(Cheers)

00:20

Are you ready to solve climate change?

00:22

(Cheers)

00:23

Good.

00:24

Do you know what a pettawat hour is?

00:27

Yeah, it's a unit of energy like kilowatt hour or megawatt hour.

00:32

I've been a climate activist since age 11

00:35

and I studied engineering,

00:36

and so I was familiar with those terms.

00:38

Kilowatt, megawatt, even gigawatt and terawatt.

00:43

But I had never heard of a petawatt hour

00:45

until I wrote a book on climate change solutions.

00:47

That's because it's so big.

00:50

But that's the scale I want to talk about.

00:52

A petawatt hour is a trillion kilowatt hours.

00:57

And today the world generates about 25 trillion kilowatt hours

01:01

of electricity each year.

01:03

Most of that is from fossil-fuel power plants,

01:06

and the dominant mindset is that we have to change

01:08

the current electricity system

01:10

by replacing those fossil-fuel plants

01:12

with clean generation by 2050.

01:16

Well, over one third of our electricity generation is already clean,

01:20

mostly from hydro and nuclear,

01:21

along with wind and solar,

01:23

and clean generation is growing.

01:25

Projections based on current policies around the world show

01:28

that we are on track to have about 25 petawatt hours

01:32

of clean electricity generation in 2050.

01:35

That's two and a half times today's amount of clean generation

01:39

and equal to today's total generation.

01:42

So this is great.

01:43

We can replace all our fossil fuel plants,

01:45

have a clean version of today's world,

01:48

walk away, we've solved climate change.

01:50

Thank you very much.

01:52

Oh, but I did forget one tiny little detail.

01:56

We actually need five times that much.

02:00

To be clear, we need and we're on track to have

02:02

two and a half times today's amount of clean generation

02:06

to switch to a clean version of our current electricity system.

02:10

But changing the current system isn't enough.

02:13

We need five times that,

02:16

all of it clean,

02:17

or 12 times today's clean electricity production,

02:21

to actually avoid the worst impacts of climate change.

02:25

Can I repeat that?

02:26

To avoid the worst impacts of climate change,

02:29

we have to multiply today's clean electricity production by 12 times.

02:35

There are four main reasons we need that much.

02:38

First, let’s keep in mind scientists’ goalpost for addressing climate change:

02:42

achieving net-negative emissions globally by around 2050.

02:47

Most of us know that to do so,

02:48

we'll have to electrify a whole range of vehicles,

02:51

heating systems and some industrial processes.

02:54

Electric equipment is more efficient than fuel-based equipment.

02:57

So electrification actually lowers total global energy demand,

03:01

but it increases electricity generation needed.

03:04

In our current energy world,

03:06

electrifying 60 percent, which is ambitious,

03:08

would add enough demand

03:10

that we would need roughly 40 petawatt hours

03:13

of total electricity generation by 2050.

03:17

Second, it's not OK to simply replace today's world with a clean version.

03:23

In today's world,

03:25

over 700 million people don't have access to electricity.

03:29

Billions more have access only to small amounts

03:32

or to unreliable supply that often cuts out.

03:35

Energy demand in rich industrialized countries will grow more slowly

03:39

over the next few decades with increased efficiency.

03:42

But energy demand in developing countries will continue to grow dramatically,

03:47

especially if we can make electricity cheaper.

03:49

This is good.

03:50

Energy access is lifting people out of poverty,

03:53

driving access to education,

03:56

commerce, health care and lower birth rates.

03:59

Both for moral and practical reasons,

04:01

those of us in richer countries need to realize that addressing climate change

04:05

will necessarily center

04:07

on a massive expansion of energy access in developing countries.

04:12

So electricity generation will have to grow even more

04:15

and get cheaper

04:16

to accommodate global economic development.

04:18

Based on projections of global development by 2050,

04:22

generation needed rises to 60 petawatt hours per year.

04:27

The third reason is a bit more debatable,

04:29

but it needs to be talked about more in public discourse.

04:32

It has to do with the fact

04:33

that not everything can be electrified by 2050.

04:36

Long-range airplanes, for instance,

04:38

are still going to need the energy density of a liquid fuel.

04:40

Similar for some industrial processes.

04:43

Now, many models waive this issue away with two overoptimistic assumptions:

04:48

that all those factories continue burning fossil fuels but use carbon capture,

04:53

which costs extra and will only happen where governments mandate it,

04:56

and that all those long-range vehicles use sustainable biofuel,

05:00

which is only sustainable if every supplying country,

05:03

and its local governments,

05:05

fully enforces strict standards for biomass

05:08

to avoid deforestation and other impacts

05:10

that could increase emissions from agriculture.

05:13

Some amount of carbon capture at factories and sustainable bioenergy

05:17

will absolutely be part of the picture.

05:19

But I’ve been in politics,

05:21

and I am sure that we should plan for imperfect policy.

05:25

And that means we need to plan

05:27

for building even more electricity generation.

05:29

We can use this additional generation to synthesize fuels

05:33

that are truly carbon neutral or entirely carbon free:

05:36

hydrogen, ammonia, synthetic jet fuel and others.

05:40

This is a much rougher estimate,

05:42

but to be confident of minimizing climate change impacts,

05:46

we should aim to push our line up to around 90 petawatt hours per year.

05:52

Finally, the fourth reason is that we need not only net-zero

05:55

but net-negative emissions in 2050.

05:58

There will be some non-energy emissions that remain, especially from agriculture.

06:02

And we'll have to pull CO2 from the atmosphere

06:04

to make up for those.

06:06

But we also need to use all our possible carbon-removal methods

06:10

at their maximum capacity

06:12

to remove more CO2 each year,

06:14

getting as far as possible in o net-negative emissions,

06:16

drawing down levels of greenhouse gases in the atmosphere

06:19

to eventually restore a stable climate.

06:22

One of the carbon-removal methods we’ll have to use is direct air-capture:

06:26

arrays of fans filtering CO2 from the air.

06:28

And doing enough of this to restore safe temperatures within decades,

06:32

not centuries,

06:33

will require yet more electricity generation.

06:36

Again, the exact amount depends on quite how ambitious we're able to be.

06:40

But for a comfortable rate of carbon removal,

06:42

we would need perhaps 120 petawatt hours per year total.

06:48

So roughly five times today's total global electricity system,

06:53

12 times today's clean electricity production,

06:56

and that can actually achieve net-negative emissions globally.

07:00

And there's a bonus reason to consider.

07:02

Because clean electricity is going to power so much

07:05

of the rest of the transition: electrification, global development,

07:08

synthesized fuels and sequestration,

07:11

to achieve net-negative emissions by 2050,

07:14

we should really build as much as possible

07:16

of that new electricity generation

07:18

at the beginning of the transition, starting now.

07:21

This will make sure that clean electricity is abundant

07:24

and cheap soon enough

07:25

to still leave time for all of the other transitions that rely on it

07:28

to fully roll out by 2050.

07:30

And when we talk about abundant and cheap electricity,

07:33

we're talking about eliminating poverty faster,

07:35

powering access to water desalination,

07:37

strengthening medical supply chains,

07:39

so much more.

07:41

Decarbonizing and scaling electricity generation

07:44

will also be the biggest global development project ever.

07:49

So if we want to avoid the worst of climate change,

07:51

we need to discard that dominant mindset

07:54

about merely replacing fossil fuel generation.

07:57

My point is, that misses the scale.

08:00

Our project is not changing the current global electricity system.

08:05

Our project is building a new global electricity system.

08:09

Political action that tinkers around within the current system

08:12

will never get us where we need to be by 2050.

08:15

Arguments over which sources of clean electricity we should use are unhelpful.

08:19

We need all of them:

08:21

hydro, solar, wind, nuclear, advanced nuclear,

08:25

advanced geothermal,

08:26

mandates for carbon capture on remaining fossil plants.

08:29

If you look at the potential rates of addition for each of these,

08:32

you'll see we need everything as much as possible

08:34

and we may still fall short.

08:38

It's not changing the electricity system.

08:40

It's building a new electricity system.

08:43

One five times bigger than today's total system

08:46

and 100 percent clean.

08:49

As fellow youth activists often say,

08:50

the project is much more comparable

08:52

to the World War II-era manufacturing boom

08:54

than anything the world has done since.

08:56

Building new things that we've barely ever built before,

09:00

in massive amounts, to create a new system entirely.

09:04

In fact, this mindset goes beyond electricity-generation itself.

09:07

Many people are wary of ambitious climate action

09:10

because they see the project as changing the familiar current world.

09:14

That's not it.

09:15

Addressing climate change means building a new world.

09:19

A world in which energy is healthier,

09:22

doesn't pollute the air we breathe

09:24

and where it's cheaper and everyone globally has access to it.

09:28

A world with higher incomes,

09:30

longer and better lives,

09:32

greater equality.

09:35

A better world.

09:37

Thank you, and let's make it happen.

09:39

(Applause)