They reckon average global temperatures will have risen by 1.5°C.
There's more discussion about striving to be close to 1.5°.
We should aim for under 1.5°. Limiting the global temperature rise to below 1.5°C.
One little number to rule them all. You must have heard of it - on the news,
chanted on the streets or maybe in your social feed. One point five.
To be fair by this point if I didn't know what it meant,
I'd be too afraid to ask, but that's where we
come in. What do we mean when we talk about 1.5° in climate change?
I'm Jordan Dunbar and I'm one of the hosts of The Climate Question podcast from the
BBC World Service. In this episode I'm asking simple questions and getting simple answers.
To help me out I've asked Dr Adam Levy or Climate Adam as he's known on YouTube.
I am a climate scientist by training and now I work as a science communicator,
climate change YouTuber and all around kind of climate change talking person.
OK so 1.5 to me has to be one of the
most controversial, talked about,
fought over and mentioned numbers, why are people banging on about 1.5° of warming?
So 1.5° of warming kind of came into everyone's consciousness as part of the Paris climate
agreement. It was actually the kind of more ambitious part of that agreement.
It said we should limit global warming to two degrees and if we're really good let's
try and limit global warming to 1.5° and then scientists,
people in policy, people just generally working in climate change really started
to look more and more into what limiting global warming to 1.5 degrees would mean.
The Paris climate agreement is something that gets talked about all the time in climate circles. It
was the global climate conference back in 2015 where the majority of polluters around the world
agreed to make cuts to their emissions to try and keep global warming under control. This
was the first time so many countries had agreed to try and tackle climate change.
Our work here is done and now we can return home to implement this historic agreement.
Why 1.5° though, why not 2° or 1.4°?
So 1.5° manages to relatively protect us from a lot of the worst consequences of climate change,
things like extreme weather events, so heatwaves, floods, droughts. It protects animals. It means we're more protected from food shortages,
but in particular it really protects the most vulnerable people and things on this
planet. So for example low-lying island nations could be just swept under by sea
level rise if we allow global warming to reach 2° and in terms of ecosystems, coral reefs,
these vital beautiful ecosystems could be pretty much eliminated from the planet.
We've spoken to someone who knows only too well the consequences of that sea level rise.
This is a very real thing that the Maldives is facing and struggling with right now.
Rae Munavaar is a journalist working for The Edition newspaper based in the Maldives
in the Indian Ocean. The warming caused by our emissions causes ice caps and glaciers to melt,
as well as making the oceans rise through expanding water. What?
I hear you say. Well grab a helmet because I'm going to blow your mind.
As seawater heats up it expands. Yes, seawater gets bigger and literally takes up more space.
So the sea rises and that is thermal expansion for you ladies and gentlemen,
which if you live a few meters above sea level is a real and present danger.
We've been advocating because this is our way of life, this is something
we're doing for survival, it's an existential threat for us.
Everything in the Maldives is less than 10m away
from a shoreline. All of our facilities from health care
to banking to emergency response to food storage to farming, all of this is at the shoreline.
So there is nowhere we have to run, there is
nothing we can do we cannot keep building higher either.
When we're talking about these amounts of global warming firstly we're talking about an average
for the entire planet, so some bits of the planet are heating faster than others but these limits
are really talking about the global average and this warming is relative sort of to pre-industrial
times before we actually got started burning fossil fuels seriously. In practice though,
in policy and in science we actually use the period 1850 to 1900 as the reference
point because that's when we have really good records to compare to and the important thing
is that scientists and policy people are all talking the same language. That they're
all referring to the same thing when we're talking about 1.5 degrees. So that we know
if we're heading towards that politically we know what the consequences of that will be.
Back in 2015 though it was a fight to get the target down to 1.5° and unsurprisingly it was
the low-lying island states, the ones most at risk who argued to get the target down.
It has become the core of the climate conversation.
Janine Felson was a strategic adviser with the Alliance of
Small Island States back in 2015. She came onto the show
and told us why she was negotiating so hard to make 1.5 the agreement.
The days and nights and mornings of Paris are still very fresh in my mind. We worked non-stop.
...the citizens of my country and the Caribbean,
who adopted 1.5 to stay alive as their mantra, their future looks much
brighter today than it did two weeks ago. brighter today than it did two weeks ago.
We were completely euphoric
1.5 is the ultimate defence line for small island developing states. That is the only
way in which we can provide any hope for our children’s future.
Honestly it's great news for the whole world that the 1.5 degree figure is this crucial figure that
the world is now focusing on because for things like extreme weather events, heatwaves which are
already devastating countries around the world you know costing tens of thousands of lives you
know limiting global warming to 1.5° it won't completely protect us from that but it will
seriously limit the risks and the harms caused by climate change. OK well this brings me to
the scary bit because there's been lots and lots of headlines saying we are going to go over 1.5
degrees warming this year. Is that true and what happens if we do go over? So what the 1.5° limit
refers to is the average in global temperatures. But that's an average over several years and so
if you have one freakishly hot year that doesn't mean the limit has been breached it really has
to be many years in a row over that limit for us to have passed 1.5° and if we do pass 1.5°
that doesn't mean game over, it's not like a switch that takes us from everything was fine
to you know world over. It's various degrees of bad and it's not like if we pass 1.5 degrees we
then just give up and say OK well two degrees of warming or three degrees of warming there's
a world of difference between every fraction of a degree of global warming. Because every
fraction of a degree brings more likelihood of extreme weather, so working towards not hitting
1.7 if we're at 1.6 means you're eliminating some of that risk. It's not game over, there's so many
more levels to play. 1.5 is not the final boss, it's just one of many bosses, right?
Yeah for sure and you know if we fail at that boss you know it sucks but
we've just got to get ourselves even more ready for the next boss.
Reload, reload, go in. Yes.
But can we actually do it? Can we stay under 1.5? So it's important that we
bear in mind that there's nothing in the physics of how the atmosphere
or the climate work that says 1.5 degrees is off the table. That is until we have passed it.
And so since we are still under 1.5 degrees of global warming,
we should really be fighting to stay under with everything we've got.
Now if we do pass it, what does that mean? There's a risk that some people will throw their hands up
in there and say "Oh that's game over, you know, we've tried and we failed, let's stop trying to
do anything about climate change, it's the end of the world". That's absolutely not what the science
shows us, it shows us that before or after 1.5 degrees of global warming we need to fight as hard
as possible to stop burning fossil fuels so we can stop the planet heating as quickly as possible.
It's clear how important trying to keep under the 1.5 degree limit is, but Adam how do we do it?
In some ways it's really easy to think about and in some ways it's really complicated.
So to stop the world from heating up there's one number you need to keep in mind, which is zero
and so reaching zero emissions of carbon dioxide means transitioning as rapidly as possible away
from fossil fuels to things like renewable energy, nuclear power, battery storage, things like this
and it also means making serious changes in how we use land, so doing things like reforestation,
protecting the forests that already exist. This is what we need to do to stop global warming
full stop, but to stop global warming at 1.5° we need to do this really incredibly quickly.
So we need to reach zero emissions overall by around the middle of
the century if we want to limit global warming to 1.5 degrees.
So that sounds like it's not about some amazing new technologies but government's
just actually taking action, actually doing things and not just talking about it.
Yeah I think a lot of people have in their heads that to achieve this would need some
magical thing like nuclear fusion to come in and save the day that's not at all the case we already
have the tools to get us most of the way to the net zero that we need to go for and you know over
the coming decades of course new technologies will be developed, but we need to start that
transition as quickly as we possibly can and the great news is yeah we have the tools to do that.
Right, let's recap. So we got to the 1.5° target to be ambitious. It lets us protect ourselves as
much as we can including the many, many low-lying islands and vital coral reefs.
If for one or two years the world is over 1.5° warmer that doesn't mean we've exceeded the
target, it's an average. So if we do go over it this year it's a warning it is not the end.
The other number we need to think about is zero. Zero emissions - we
have to get fossil fuel emissions down and fast. The good news is
we don't need any mad futuristic technologies to do a lot of this.
We have the tools we need right now but companies and governments have to use them rapidly and in
huge numbers and the best available evidence suggests once we get emissions down to zero
the temperature will begin to drop. If you want to know more we've got some other amazing explainers,
like 'What is climate change?' and 'What is COP?' which you can find wherever you
get your podcasts. The Climate Question takes all of the issues we've heard about and tackles
them with a global perspective so wherever you live we'll be finding out how climate change is
affecting you and what can be done about it. Join us each week to meet experts, activists, actors,
businesses, scientists and everyday people as they deal with the world's biggest challenge.