- With all the bad and
often terrifying news about climate change, doomsday may seem like it's just around the corner. But is it? There are electric cars, solar panels, and wind turbines everywhere. Still, we've wasted a lot of time arguing over if and why global
warming is even real, let alone a priority. So how are we doing? Well, in the early 2010s, a
set of emissions scenarios called RCPs ranging from
very stringent climate policy to no climate policy at all was developed to represent what warming
could look like by 2100. To get an idea of how we're doing, we asked experts in the field
which one of these scenarios looks most likely today. These scenarios were developed in the wake of the global financial
crisis, when emissions dropped for the first time in the history of many developed countries, but by 2010, they had begun to rebound
along with the economy, and developing countries
with enormous populations like China and India were
planning massive investment coal plants to power economic growth for billions of people. - If you had asked me 10 years ago whether I thought we would be in the place we are today, I would've
thought that it would've been very unlikely, I would've thought that there's no way that that's possible. (ominous music) - So where are we today? And where are we going? The RCP origin story
can help us understand. - Back in the lead up to the
IPCC fifth assessment report that came out in 2013, the
energy modeling community developed four pathways,
which were essentially four different possible warming outcomes at the end of the century. - Now the Representative
Concentration Pathways all come with a number,
for example RCP 2.6, RCP 4.5, or RCP 8.5. That number is essentially the imbalance in earth's energy budget
resulting from human influence on climate, and that number is expressed in watts per meter squared. - So in the case of RCP 8.5, this means that humans would have emitted
enough greenhouse gases into the atmosphere to add
an additional 8.5 watts per meter squared of solar
radiation to the climate by 2100. And considering how many square meters are on earth's surface,
that's a lot of watts. This many, to be exact. Each of the RCP levels
projects an estimated average of global warming. RCP 8.5 is close to five degrees, RCP 4.5 is just below three degrees, and RCP 2.6 represents
the Paris Agreement goal of limiting warming to
well below two degrees. RCP 8.5 with its associated
five degrees of warming is truly an apocalyptic scenario. It means game over, an existential threat. It models a world with no climate policy, and it's hard to argue that we had or have an effective climate policy either domestically or internationally. - Because RCP 8.5 was the
only one of the RCPs run with no climate policy, a lot of people started referring to it
as business as usual, or in a world without climate policy, we'll have, you know,
five degrees of warming. - Emissions were just increasing
year after year after year. There was the Kyoto Protocol in 1992, and it was widely considered
to have been a failure. It really seemed feasible
that we could end up on a pathway where coal use
would continue to expand, where we would continue to prioritize sort of fossil fuel economic growth throughout the remainder of the century. - And a real problem seemed to emerge with reducing emissions. So far in the 20th century,
increasing carbon emissions had been correlated with
increasing gross domestic product, and even reducing poverty. China's emissions were growing very fast along with their economy, and
even with all the problems associated with rapid development, they were lifting citizens out of poverty. Other developing nations
hoped to follow their lead, and coal was the fuel of choice. Could the developed
world, comparatively rich after more than a century
of burning fossil fuels, really ask them to give up on coal? And that's when something
very important changed. In the 2008 global financial crisis, the emissions of many developed countries did what they had always done,
they followed the economy, downward this time. But then, economies rebounded. After a brief uptick, the emissions of large carbon polluters like the US, EU, and Japan surprisingly continued to fall, even in a world with no
functioning climate policy. And GDP continued to rise. - We're not in "business
as usual" anymore, or at least "business
as usual" has changed. - So what exactly changed?
And should we still call RCP 8.5 "business as usual?" - You know, RCP 8.5 is very much a world dominated by coal. By 2100, global coal use
has increased sixfold above 2010 levels, and global
emissions have tripled. In the real world, global
coal use has been flat, if not slightly declining since 2014. You know, clean energy costs
have fallen dramatically, solar is 90% cheaper in the last decade. Wind is 66% cheaper,
batteries are 90% cheaper, you know, electric vehicles are about 14% of new vehicle sales globally now, and upwards of 20% in places
like China and Europe, and so you know, we're
having an energy transition that was not accounted
for in these sort of worst-case scenarios a decade ago. - Seaver described this transition as one where activists, advocates, and even scientists push
for emission reductions. No one got exactly what they wanted, but there was just enough government and society support to create a tailwind for innovators, even
while the U.S. was busy pulling out of international agreements. - You can't really just
disentangle sort of state policies from real acceleration in
private sector clean energy. It was actually because
of early subsidy programs in Japan, in Germany, and
in China in particular, that really helped fill in the gap between what was economically feasible and sort of what needed to happen. - This is all extremely good news, and we're no longer in a
no climate policy world, at least not entirely. In 2015, the Paris Agreement was signed, creating voluntary benchmarks
for countries to meet in order to stay well below
two degrees of warming, or RCP 2.6. However, almost no countries
are actually on target to meet their benchmarks,
and the four largest emitters have a long way to go to even get close, so at this point, RCP 2.6
is also not very likely. - And so that's the
reason why we think now that the world is probably
headed toward a bit under three degrees under current policies and sort of technological developments, rather than you know,
close to five degrees, where some people thought we were headed. - But even if two degrees of warming is still hugely ambitious,
isn't it cause for celebration that we've come so far
from the old projections of five degrees? - You know, it's probably not literally the end of the world, I
think humanity could survive in a world of three degrees,
but it's not a world we want to leave to our children. - You know, the IPCC was very clear, saying that every little
increment of global warming is gonna make things
more difficult to face, come more frequent heat
waves, worse floods, more intense hurricanes,
more prolonged droughts. - We've already warmed 1.1 degrees, so we're talking about almost three times what we're experiencing today. - If you think about
being a young person at 40 and how it's gonna be at
80, I feel like it's similar to a world where everything is getting a little more difficult, a little worse, and all the risks are increasing of, you know, catastrophic outcome. - And the list of impacts
goes on and on... and on. But perhaps the most important reason to curb emissions is not
just to stop warming, but to slow it down. - So a scenario like
RCP 8.5 warms quickly, and therefore, doesn't
leave us enough time or challenges our adaptation by changing the climate not only a lot, but fast. And a scenario that limits
warming at two degrees is not only beneficial
because of that sheer point, but also because by definition, it's going to do that slowly, and
therefore, letting society but also importantly the
natural ecosystems adapt. - At the current rate of
warming, human adaptation has actually been working
out pretty well so far. In fact, according to WMO,
over the last 50 years, the number of disasters
globally has increased by around 400%, while the number of deaths has fallen by two thirds. - Right now, rich
countries could potentially adapt to these changes, poorer countries will have a lot harder time doing so, and there may well be a
world where we don't do a great job of solving poverty or some of these other challenges
that face humanity today. And so to have that
world with climate change on top of it could
potentially be catastrophic for a lot of societies. And so yeah, I'd like to hope for a world where we all become rich
and equal and high tech and can deal with three
degrees of warming, but I don't want to bet
on it, and I don't want to bet the future of humanity on it. - And our current trajectory
of RCP 4.5 looks likely to trigger some of the tipping elements we discussed in an earlier episode. So limiting warming to
under two degrees, RCP 2.6, or even RCP 1.9, is a new target for avoiding the worst
impacts of climate change, and this will require
getting all global emissions down to zero in just the
next 50 years or sooner. - You know, right now we are
dealing with the easier parts of the economy to decarbonize. So you know, I'm, I think
it's gonna be a heavy lift. So we're not just talking about emissions in the U.S. and Europe, we're also talking about China, we're talking
about sub-Saharan Africa, which is a huge amount of you know, development and growth
expected over the next century and needed over the next century, and we're talking about, you know, all the different players in the world aligning on these sort of goals. The good news is that we've started to see more commitments by
countries to do just that. So as of 2022, about
75% of global emissions are covered by countries
that have committed, at least on paper, to
get to net zero emissions by the middle to late 21st century, and that includes countries
like China and India, Japan, South Korea, Brazil,
as well as of course, the U.S., the EU, and others. - While we have solutions
for things like decarbonizing the electricity system or
the transportation system, there are large, unsolved
challenges in areas like heavy industry and
shipping and aircraft. - But I'll be honest, what
I take from this episode are two things. First is the fact that humanity created a reality of goals that
felt like a fantasy just a few years ago. As just one example,
in 2006, a documentary called "Who Killed the Electric Car" detailed all the government
and industry resistance to electric vehicles. Now, the U.S. government will pay you thousands of dollars to buy one, and they're everywhere. And second, the reason
this remarkable progress was able to occur was
because people fought for it. - I think the fact that we've already made so much progress in the last decade toward bending down the
curve of future emissions, should be a hopeful sign. It's evidence that we can
actually solve this problem if we collectively get our act together. At the same time, we can't
be blindly optimistic. We can't assume the
technology is gonna solve all our problems, we can't
assume that the problem is gonna solve itself,
we need concerted action by governments, we need policy, and we need people to get
involved in pushing that, 'cause we're not heading toward a world we want to leave future
generations right now. We might not be heading
towards the literal apocalypse anymore, but we're still heading toward a pretty bad outcome,
and we can do much better. - And now it's time to
hear what you think. Are we too alarmist,
or not alarmed enough? Considering how far we've
come in the last decade, is it possible we can shift
business as usual again, this time, from RCP 4.5 to RCP 2.6, and keep global warming under two degrees and a planet we all want to live on? You're watching "Weathered,"
so you're probably passionate about fighting climate change. You might also be interested
in The Earthshot Prize. Created by Prince William,
The Earthshot Prize aims to spotlight and fund
groundbreaking solutions to the world's most urgent
environmental challenges. Check out The Earthshot Prize over on the PBS YouTube
Channel, and get to know the amazing scientists who were awarded more than $1 million each. The link is in the description below. (calm music)
