We're facing an urgent crisis.
One which threatens our very existence,
the Climate Catastrophe.
The climate stability of the
past twelve thousand years
has come to an end
and around the world we are now
suffering from the impact.
Bleached coral reefs
becoming cemeteries.
Polar regions melting.
Species driven to the brink of extinction.
It doesn't make any sense if you think
we're the most intellectual creature 
on the planet,
that we're destroying our only home.
We are at a critical juncture
in our planet's history.
What each one of us does
in the next few years,
will determine what happens in the
next few thousand years.
It will define our legacy 
to all future generations.
One of the things that
concerns me the most is just the scale
and the urgency of the challenge.
If you look at our current emissions of carbon
dioxide they're continuing to increase
like this and if we look at the
trajectories that we need to be on if we
are to avoid exceeding 1.5 degrees of
warming we need to essentially reverse
that - today.
It's really obvious that the
climate change that we're experiencing is
due to human activity and the reason
really comes partly from the ice cores.
From the ice cores, we know that the
carbon dioxide concentration today at
just over 400 parts per million is about
40% higher than it's been at any time in
the previous 800,000 years. And that
tells us we ought to get climate warming,
and sure enough when we look at the
records we do have climate warming of
about a degree globally over the last
hundred years. So those two things put
together a really the smoking gun.
The amount of data we're getting is just
fast from satellites, from climate models
and from our sensors. We need artificial
intelligence or AI to really tackle
some of those large datasets. To look for
those patterns and interconnections in
these data sets which are previously
hidden to traditional techniques.
AI will enable us to build improved predictive
models for future climate change.
The level of detail from these will be a
game-changer for governments,
for policymakers and businesses who require
to make decisions.
The transition we have to make to hit 
zero carbon in 30 years time
is going to change the whole economy.
Every aspect of it is going to have to change.
We need to ship trillions of dollars
worth of investment over the next few
decades and they need to be deployed to
do things like make all of our homes
energy efficient and Net Zero, we need to
have decarbonisation of Agriculture,
we need to see the entire electrification
of our energy and power systems so that
we can run off all renewables.
And all of that needs to be financed.
The primary source of greenhouse gas is the way we
generate and use energy.
It is burning coal, oil and gas.
The biggest opportunity
now is that we now have technologies for
energy generation and energy storage
that are zero carbon.
So in Cambridge, we have fabulous work on
high voltage electronics which is transforming the
way we move electricity around.
Our work on batteries is pushing the performance,
particularly how long you can use a
battery for, to unexpected heights.
We have absolutely groundbreaking work on
new approaches for solar cells.
And the challenge of how we can handle different
parts of the solar spectrum more
efficiently using a sequence of
different semiconductors to pick out
different colours, is the big opportunity
to get the next big drop in the cost of solar.
The generation of electricity that comes
from renewable sources was enabled by a
huge number of government policies
throughout the world in the U.S. in
Germany, in Japan and in China
that really created early markets
for these technologies
while they were still expensive.
The challenge is, that the
rest of the world is growing richer,
faster and as it does so it uses more energy.
So the conversation regarding the
emerging economies, and I've done a lot
of work on China and India has changed a
little bit between the Copenhagen
agreement and the Paris agreement.
Both China and India signed up to the Paris
agreement as equal partners to countries
like the UK, the United States and so
forth and increasingly these countries
are seeing a low-carbon economy or the
green economy as an opportunity more so
than a threat. They're investing in these
technologies. China is now the largest
manufacturer and deployer of solar
panels, wind turbines and Lithium-ion
batteries. India has put very aggressive
policies in place to also, both build
solar panels but also try to develop a
local manufacturing sector.
increasingly, we're getting to a point where it's not
a matter of either/or you can design
policies that can try to domestically
that can try to both reduce greenhouse
gas emissions and also contribute to
local development.
Cities by their nature
are energy intense environments and if we
for a minute just focus on built
environments - buildings, just to get to
the level where we are even coming close
to meeting the 2050 carbon targets, we'll
have to be very aggressive
in what we do from all angles.
A lot of our built environment already exists.
We have to be very aggressive about retrofitting it.
We have to also continue strategies to
incentivise reduction of demand and
finally that reduced amount of energy
per household needs to be supplied by
carbon neutral sources
such as renewables.
In addition to retrofitting
built environments we have a couple of
exciting projects that are currently ongoing.
One is on urban farming which is
making use of derelict spaces across
cities to grow food.
So the second project that we have ongoing is on
subsurface environments.
If we understand where the significant sources
of heat are and their magnitude, 
then we can tackle them sustainably.
So we can
actually use those heat sources where we
have heating needs above ground.
What we eat and how we produce food matters a
huge amount not only for our own health
and well-being but for the planets as well.
Agriculture is the human activity that's
transformed the world the most.
Producing food takes up 40% of the
world's land surface, it's responsible
for approximately 25 percent of human
greenhouse gas emissions and also about
70 percent of fresh water withdrawals.
It's vitally important we moved to a lower
meat and a more plant-based diet.
Animal agriculture has a disproportionate
impact, a very high carbon footprint.
A recent report came out in 2019, that
devised the planetary health diet and
essentially they recommend a small
amount of meat, fish and dairy, a lot of
vegetables, a lot of beings and pulses
and some fruit.
The amount of meat that they're recommending
adds up to about 15
kilos per person per year, to feed 10
billion people safely within planetary
boundaries. Let's call that 20 kilos per
person per year to take into account a
food waste.
In the UK on average per person
we're eating four times that
at over 80 kilos and that itself is
double what the average global citizen eats.
There are many other steps that are
also important but if you're going to make one change,
reducing clean dairy consumption
has the biggest suite environmental benefits.
So decarbonisation is one of
the great challenges facing humanity.
Electricity production produces about 25 %
of the world's CO2, and aviation
produces about 2%
of the world's CO2 but is rapidly growing.
We're working on
electrical and hybrid propulsion for
aircraft, in terms of land-based power
we're working on power generation from
low-grade heat such as solar plants.
We're working on tidal turbines,
extracting energy from the Earth's tidal
flows and we're working on hydrogen base
cycles which remove the need for fossil
fuels completely.
The Whittle Lab is also working on reducing
the emission of current technologies.
Rolls Royce is producing its first major new engine
the UltraFan engine, which will reduce
emissions by 25% and the Whittle lab is
doing a lot of research on technologies
that will go into that engine.
Taking an innovative idea and making it into a reality,
is an incredibly difficult process and
what the Whittle Lab has done over the last
50 years is through a close interaction
between industry and academia we've
built a bridge to allow these great
ideas that are produced in Cambridge to
be translated into real products and
that is what is needed if we're going to really
successfully decarbonise the power 
and propulsion  sectors.
So we have to work out
how within the UK we can get existing
and developing and completely new
technologies up to scale very quickly.
What really makes that work is when it's
economically attractive to do so.
And there are many ingredients to that: we
need skills, we need the right
spread of competences in the UK, we need
the right availability of investment and
we need the ambition that that's where
we're going to get to.
We have a very exciting research initiative in
looking at how and provide and  
preserve a carbon future s in the world.
That has to be complemented by the
University itself looking at its own
operations and having a pathway
to zero carbon for the University. So
those targets will worry about different
scopes of emission so for scope one
emission which is largely the gas that
we burn on the estate. And we're looking
at how to get rid of that that's going
to cost a few hundred million over the
next ten years to get rid of.
Scope 2, largely the electricity we buy to make
sure that we're buying that from
renewable sources where we can trace the
provenance of what we're doing.
Scope 3 is hard,
that's everything else. That includes air
travel we hope that we'll have a policy
about limiting air travel coming up this
year and also providing greater
transparency about our actual air travel.
That Scope 3 includes things like
stopping serving ruminant meat in
our catering outlets. It also includes
everything else we buy.
And this is tough but one of
the things that's driving our new
procurement system will be consideration
of how we account for the carbon in that
and how we reduce the carbon by being
selective about what we buy and from whom we buy it.
Then we need to play a role in
shifting policies, regulations, practices
of investment firms and other
institutional investors as quickly and
as effectively as possible. And
preferably based on the research that we
do here so that we're picking the things
that are the most effective and moving
as quickly as possible in this very
brief period we have
to make the difference we need to make.
As a climate scientist,
I'm deeply aware of the scale of the
threat posed by climate change.
But at the same time I really am genuinely
optimistic that if we harness
the excitement and the energy and the
enthusiasm around responding to that
great challenge, bringing together the
ideas and the innovation, inspiring a
future generation of leaders with the
skill set that's going to be required to
navigate through the coming decades, then
maybe, maybe we do have an opportunity to
really make progress and to tackle this
global problem. But above all else it's
very clear this is something on which
we cannot fail.
There are huge opportunities to getting things right.
The only way to operate is to believe
we can do something about it
and I truly think we can.
