20 20 13 February 2021 | The Guardian Weekend13 February 2021 | The Guardian Weekend
There are two numbers you need to know about
climate change. The fi rst is 51bn. The other is zero.
Fifty-one billion is how many ton s of
greenhouse gases the world typically adds to the
atmosphere every year. Zero is what we need to
aim for. To stop the warming and avoid the worst
eff ects of climate change, humans need to stop
adding greenhouse gases to the atmosphere. The
climate is like a bathtub that’s slowly fi lling up
with water. Even if we slow the fl ow of water to
a trickle, the tub will eventually overfl ow. Setting
a goal to reduce our emissions won’t do it. The
only sensible goal is zero.
This sounds diffi cult, because it will be. Take
this past year: economic activity has slowed down
so much, due to Covid-19, that the world will emit
fewer greenhouse gases. But the reduction will
probably be about 5%. In real terms, that means
we will release the equivalent of 48 -49bn ton s of
carbon, instead of 51b n.
Consider what it took to achieve this 5%
reduction. More than 2 million people died and
tens of millions were put out of work. To put it
mildly, this was not a situation that anyone would
want to continue or repeat. And yet the world’s
greenhouse gas emissions probably dropped just
5% , and possibly less.
This small decline in emissions is proof that
we cannot get to zero simply, or even mostly, by
fl ying and driving less. Just as we needed new
tests, treatments and vaccines for the novel
coronavirus, we need new tools for fi ghting
climate change: zero-carbon ways to produce
electricity, make things, grow food, keep our
buildings cool or warm, and move people and
goods around the world.
I am aware that I’m an imperfect messenger on
climate change. The world is not exactly lacking
in rich men with big ideas about what other
people should do, or who think technology can
fi x any problem. I own big houses and fl y in
private planes – in fact, I took one to Paris for the
climate conference, so who am I to lecture anyone
on the environment?
I plead guilty to all three charges. I can’t deny
being a rich guy with an opinion. I do believe,
though, that it is an informed opinion, and I am
always trying to learn more.
I’m also a technophile. When it comes to climate
change, I know innovation isn’t the only thing
we need. But we cannot keep the Earth liveable
without it. Techno fi xes are not suffi cient, but
they are necessary.
It’s true that my carbon footprint is absurdly
high. For a long time I have felt guilty about
this. Working on this book has made me even
more conscious of my responsibility to reduce
my emissions; shrinking my carbon footprint is
the least that can be expected of someone in my
position. In 2020, I started buying sustainable
jet fuel and will fully off set my family’s aviation
emissions in 2021. For our non-aviation
emissions, I’m buying off sets through a company
that removes carbon dioxide from the air and
a nonprofi t that installs clean energy upgrades in
aff ordable housing units in Chicago.
I’m also investing in zero-carbon technologies.
Some things, like electricity and cars, get lots
of attention, but they are only the beginning.
Passenger cars represent less than half of all the
emissions from transportation, which in turn
is 16% of all emissions worldwide. Meanwhile,
making steel and cement accounts for around 10%
of all emissions.
Each year, America alone produces more than
96m ton s of cement, one of the main ingredients
in concrete, and we’re not even the biggest
consumers of the stuff – that would be China,
which installed more concrete in the fi rst 16 years
of the 21st century than the United States did in the
entire 20th century.
To make cement, you need calcium. To get
calcium, you start with limestone and burn it
in a furnace until you end up with the thing
you want – calcium for your cement – plus
something you don’t want: carbon dioxide.
Nobody knows of a way to make cement withoutgoing through this process. It’s a one-to-one
relationship; make a ton of cement and you’ll get
a ton of carbon dioxide.
Between now and 2050, the world’s annual
cement production is predicted to go up a bit, as
the building boom slows in China and picks up
in smaller developing countries before settling
back down near 4bn ton s a year, roughly where it
is today. Cement is a tough case, but a couple of
companies have good ideas.
One approach is to take recycled carbon dioxide
and inject it back into the cement before it’s used
at the construction site. The company that’s
pursuing this idea, CarbonCure, has several
dozen customers already, including LinkedIn
and McDonald’s. S o far it’s only able to reduce
emissions by around 10%, though it hopes to get
to 33% eventually.
Another, more theoretical, approach involves
making cement out of seawater and the
carbon dioxide captured from power plants.
The inventors behind this idea think it could
ultimately cut emissions by more than 70%.
I’ve put more than $1bn into approaches that
I hope will help the world get to zero, including
aff ordable and reliable clean energy and low-
emissions steel, meat and cement. Of course,
investing in companies like these doesn’t make
my carbon footprint smaller. But if I’ve picked
any winners at all, they will be responsible for
removing much more carbon than I and my family
are responsible for. Besides, the goal isn’t simply
for any one person to make up for his or her
emissions; it’s to avoid a climate disaster.
When the global economy went into severe
recession in 2008, public support for action on
climate change plummeted. People just couldn’t
see how we could respond to both crises at the
same time. This time is diff erent. Even though the
pandemic has wrecked the global economy,
support for action on climate change remains
high. Our emissions, it seems, are no longer
a problem that we’re willing to kick down the road.
The question now is this: what should we do
with this momentum? To me, the answer is clear.
We should spend the next decade focusing on the
technologies, policies and market structures that
will put us on the path to eliminating greenhouse
gases by 2050. It’s hard to think of a better
response to a miserable 2020 than spending
the next 10 years dedicating ourselves to this
ambitious goal Bill Gates’ How To Avoid A Climate Disaster: The
Solutions We Have And The Breakthroughs We
Need is published by Allen Lane on 16 February
at £20. To order a copy for £17.40, visit
guardianbookshop.com‘Without
innovation,
we cannot
keep the Earth
liveable’
An exclusive
extract from
How To Avoid A
Climate Disaster
‘I’ve put more
than a billion
dollars into
approaches
that I hope will
help the world
get to zero
emissions’