I have a confession to make.
I feel bad about flying.
And I know I'm not the only one here.
I love to travel, but I know it's hurting our environment.
When I was six years old, I moved to Taiwan.
My family, we boarded a regional jet in Iowa,
and 30 hours later we stepped off a 747 in Taiwan.
Airplanes had taken us halfway across the globe.
And I felt the wonder of a new world.
Air travel,
it builds bridges and it connects us.
It takes families and people to new lives and new experiences.
But it also comes with a cost.
A cost to our climate.
When I first started focusing on the aviation sector,
I quickly learned that aviation accounts for
about two percent of global CO2 emissions.
And while that number may seem small,
it could grow to 20 percent by 2050 if no action is taken.
And for those of us that do fly regularly,
it can be the biggest component of our individual carbon footprint.
That trip I took when I was six,
if I were to make the same trip today,
I would have to be vegetarian for nearly four years
to make up for the carbon and other emissions from that trip.
And so that's why I'm conflicted.
And it's also why I'm working with the aviation sector
to figure out how to decarbonize as soon as possible.
The next thing I learned is this:
decarbonizing aviation, it's no easy task.
Traditional jet fuel is so very good at its job.
It’s cheap, and it’s energy-dense.
And because of that engines, airplanes, airports,
fuel supply chains and regulations,
they are all built on flying planes from point A to point B
that run on jet fuel.
And those planes that run on jet fuel,
they're operated for 20 to 30 years on average
before they're retired.
That means a plane that's ordered today will be flying until around 2050.
So we can't get there on engines and airplanes alone.
If we want any hope of reaching our goal of zero emissions,
we need to find the mix of solutions now.
There's three broad buckets that we need to address.
The first is how we design and fly planes.
The second are the fuels that we use, namely biofuels, to power those planes.
And the third is new and emerging technology
that can entirely change the game.
Let's start with how we design planes.
Well, the basic design of a plane doesn't change much
from one generation to the next.
Improvements in aerodynamics, reductions in cabin weight
and even improved engine efficiency
means that each generation of aircraft
is about 20 percent more fuel-efficient than the last.
Now, that's great.
But turnover is slow, and so there's more we can do.
We can also fly planes differently.
Flying planes differently means changes to airport management,
to air traffic control, even individual pilot behavior.
If a plane sits on the runway for less time before takeoff,
we can reduce emissions.
If a plane takes a more direct route instead of flying around national borders,
we reduce emissions.
And if individual pilots don't gun it at takeoff,
we can also reduce emissions.
Now, these changes, they may sound easy, but they're not.
We all know that individual behavior change,
it doesn't always stick.
And changes to airports and air traffic management,
that's a really long march.
My team estimates that if we were to really prioritize
designing and flying planes differently,
we could reduce 2050 carbon dioxide emissions by 30 to 40 percent.
We need to do this.
But we need more.
We also need biofuels.
And for biofuels or bio-based, sustainable aviation fuel,
you need funding and you need feedstock.
Let's start with feedstock.
Biofuels are based on biological sources, like grains and oil seeds,
forestry residue, used cooking oil, even municipal solid waste.
You can take trash and convert it to fuel
in a way that meaningfully reduces emissions.
But there's a catch.
There's only so much forestry residue.
And there's only so much land that can or should be converted
to grow crops for fuel
without impacting global food supply chains.
And then there's funding. Biofuels are expensive.
They're more expensive than traditional jet fuel
and could raise ticket prices to consumers by 10 to 20 percent.
And we need a massive initial investment
to build the production facilities to meaningfully supply the sector.
It's a classic chicken and egg problem
because prices are high, there’s no demand.
And because there’s no demand, there’s no supply.
And because there's no supply,
prices aren't coming down and so there's no demand.
And on and on and on.
Thankfully, we are finally starting to break the cycle.
The European Commission recently proposed an alternative fuels mandate
of 5 percent by 2030 and 20 percent by 2035.
And there's even pressure to accelerate that.
A far cry from the .01 percent of biofuel usage
that we were at in 2018.
My team estimates that if we were to really focus on biofuels,
we could further reduce 2050 CO2 emissions by 10 to 30 percent.
That leaves us with a gap of 30 percent. That’s not good enough.
It doesn’t get us to our goals,
and it certainly doesn't absolve me of my guilt
when I consider getting on a plane.
The third bucket of things we need
lies in breakthrough, innovation and invention.
You have synthetic fuel,
which, like biofuels, works with existing engine technology and airplane design.
Synthetic fuels or e-kerosene actually take carbon dioxide from the air,
combine it with hydrogen that's cleanly separated from water
to produce fuel.
The science is amazing.
But it's really early days, it's small-batch and it's expensive.
And then you have hybrid electric and electric aircraft:
small planes that run on batteries.
By 2050, these planes could fly for short distances.
And then there's hydrogen. Green hydrogen.
There's hydrogen fuel cells, batteries that run on hydrogen,
or hydrogen-combustion engines, engines that use hydrogen as fuel.
These also show promise, and we need to continue to invest in them.
These new fuels pair really well with new aircraft design,
like the blended wing body where there's no clear dividing line
between the main body and the wings of the aircraft.
These planes could be at least 20 percent more fuel-efficient
than traditional aircraft.
And they create the opportunity to rethink where fuel is stored
so we can use new energy sources, like hydrogen.
Now, some of these innovations, they'll work, and some may not.
We may need to rely on high quality removals
like carbon capture and storage.
What is clear is that if we want any hope of getting to zero emissions,
we will need some of these and potentially other technologies.
There are challenges: ensuring the safety of these technologies,
investing billions and billions of dollars
to build the production facilities and supply chains
for biofuels and synthetic fuels.
And making sure that each and every country does its part.
If it sounds hard, that's because it is hard,
but it's not impossible.
I think we can get it done.
The hard work, it's already starting.
The sector is innovating and investing and collaborating,
and that hard work, it needs to continue.
And it needs to intensify.
And while that hard work happens, I'll remain conflicted.
I want to travel.
I want to see friends and family and colleagues.
And so there's a few things I do.
I ask myself: Do I really need to make that trip?
I work with my company to advocate for biofuels,
to try to break that chicken and egg cycle.
And I try to fly on the most climate-friendly
and fuel-efficient airlines.
We all know that individual choices can drive collective action.
This sector, like many others,
is one where the entire industry has to work together
if we want to reach our goal.
Thank you.
(Applause)