Benjamin Cook: "Global warming is caused by cow farts."
It's not by their farts, but it's by belching.
Cook: "A few degrees' difference is not a big deal."
And the way I always like to think about it too
is like your body's temperature.
If your temperature is three or four degrees warmer,
then you're seriously sick.
"It's too late to do anything about it."
Unless you're Elon Musk
and gonna head off towards Mars,
we're all stuck here,
so we should try to figure out
how we can make it the best planet we can.
I'm Deepti Singh.
I'm an assistant professor
in the School of the Environment
at Washington State University.
I've been studying climate change for about 11 years,
and I study extreme weather events
and how human activities are influencing them.
My name is Benjamin Cook, and I'm a climate scientist
at the NASA Goddard Institute for Space Studies.
I've been working there for about 14 years now.
And I study how droughts are changing
with global warming and climate change.
And today we'll be debunking myths about global warming.
Cook: Myths from pop culture.
Oh, boy, I'm glad you got this one, Deepti.
"The sun is causing global warming."
Changes in the amount of energy we get from the sun
do affect our climate.
But over the last 150 years, we know that
because the amount of energy we're getting from the sun
has not changed significantly over this period.
Satellites have been recording
the amount of solar radiation that our planet receives.
I think Ben has a graph that shows that.
Cook: And what we're looking at here on the yellow
is the amount of energy that's coming from the sun,
and red is global temperatures.
It's pretty clear that the amount of energy
we're getting from the sun has been more or less flat
for the last several decades,
even as temperatures continue to go up and up.
Singh: "Scientists don't agree
on what causes climate change."
100% of the climate scientists on this Skype call agree.
If you review the published literature
in reputable journals by reputable scientists,
all those papers agree
that climate change is caused by human activities.
There's really no other explanation that fits the data.
We've looked at the sun.
We've looked at just natural variations
in circulation in the ocean, in the atmosphere.
We've looked at volcanoes.
We've looked at changes in ecosystems.
And at the end of the day, the only thing
that can adequately explain the degree of warming
that we've seen over the last 150 years
is human greenhouse gas emissions,
primarily through the burning of fossil fuels.
There's a real clear incentive
for people to find some other explanation.
Nobody can come up with
even a plausible alternative hypothesis.
"Global warming is caused by cow farts."
It's not by their farts, but it's by belching.
Agriculture is a pretty substantial contributor
to greenhouse gas emissions, close to 25%.
It's not the whole 25%, but it's a good chunk.
It's important to note, too, that even the cow burps
that are producing this methane is not natural.
It's all part of a kind of human agricultural system.
So blaming it all on cows
doesn't take people off the hook.
"Plants and animals will adapt."
So, we know that in the past,
plants and animals have adapted to climate change,
but there's a few fundamental different things now
that are very likely to make it quite difficult.
In addition, it's not just climate change
that's threatening plants and animals,
it's habitat fragmentation,
it's pollution,
it's a variety of other environmental stressors.
And so once you kind of put climate change
on top of pollution, on top of habitat loss,
then it becomes much, much more difficult.
And just to add to that,
I think the extinction rate of species is much higher
than the natural extinction rate.
And it's partly driven by
the processes that Ben just mentioned.
Cook: Myths from social media.
"Global warming is natural."
So, we know in the past that climate can change
really dramatically from natural causes.
The climate during the time of the dinosaurs
is very different from the climate
during the time of the last ice age.
But the changes that we're seeing right now
for the most part are not natural.
The warming that we're seeing is very likely
the fastest warming we've seen
anytime in the last several thousand years.
It coincides directly with the industrial revolution
and the burning of fossil fuels
and widespread deforestation.
You can look at almost any natural cause,
and none of them are sufficient to explain
the warming that we've seen in recent decades.
"Carbon dioxide is the problem."
So, CO2 isn't the problem.
It's the increase in the concentration of CO2
in the atmosphere that is resulting
in the rapid warming we're seeing
over the last century, which is the problem.
So, carbon dioxide is one of these gases
that we call greenhouse gases,
because they're responsible for the greenhouse effect,
which basically helps trap energy on Earth
and make things much, much warmer
than it otherwise would have been.
It's not a big stretch then to observe
that if we start increasing CO2 concentrations,
we're gonna trap more energy and we're gonna warm up.
Before the industrial revolution,
CO2 levels were close to, like, 280 parts per million.
And now we're at close to 418 parts per million.
So that's a pretty large change in the concentration.
And the fact is that pretty much anytime
the world was warmer,
CO2 levels in the atmosphere were higher.
And anytime the world was cooler,
CO2 concentrations were lower.
"A few degrees' difference is not a big deal."
And the way I always like to think about it too
is like your body's temperature.
We're all supposed to be about 98.6 degrees Fahrenheit.
Even one degree or two degrees of warming
is considered a low-grade fever.
And if your temperature is three or four degrees warmer,
then you're seriously sick.
So, just to give you a sense,
the Earth has warmed by about one degree
over the last century.
That one degree is an average temperature around our planet.
That means some parts of our planet
are warming faster than others.
I come from India.
We have a lot of people
that live below poverty in the country.
And most of those people, for example,
don't have an air conditioner
to deal with extreme heat events.
So it depends on who we're talking about
when we say it's not a big deal,
because there are some people around the planet
that have the capacity to adapt or cope
with these kind of extreme events
and with the warming that we've experienced,
and then there are billions of people
that do not have the capacity to cope
with even small changes.
Myths that we, climate scientists, hear the most.
"Global warming will destroy the planet by 2030."
Just like there's kind of climate deniers
who don't know what they're talking about,
there's climate doomists
who also don't know what they're talking about.
This whole idea of the planet
being destroyed by 2030 comes out of discussion
about, how much time do we have
to keep global warming under two degrees?
And so it's very likely that we need to
kind of get emissions under control by 2030
to keep it under two degrees.
It doesn't mean that the world is going to explode
or we're all going to be consigned
to a fiery "Mad Max" kind of hellscape.
It just means that it'll be warmer
than we maybe wanted it to be.
When they say it's gonna destroy the planet,
well, the planet's not going to blow up.
But it does mean that the way of life
and the livelihoods
and the things people depend on
are going to be affected.
There are already people who have been displaced
because of sea-level rise,
people that are experiencing
life-threatening heat conditions.
The impacts of climate change
are not going to be equally felt.
These kind of blanket statements
are very, very dismissive.
And I think they can take attention
away from the people who are likely to be
most vulnerable to climate change.
It's not really helpful to put a date on it.
I think we just need to know that
delaying action on climate change
is going to just cost more to society.
Cook: "Global warming is China's fault."
So, to address that myth,
I think there's one important fact we need to understand.
When CO2 is emitted,
it can stay in the atmosphere for hundreds,
if not thousands of years.
The CO2 concentrations we're seeing today
are a consequence of emissions that have happened
over a much longer period, over the last century.
And most of those emissions are associated
with the industrial revolution
and development of countries like the US
and industrialized nations in Europe.
If we look at emissions this year specifically,
sure, the emissions from China
are close to what the emissions from the US are.
But those emissions are being used
to produce products and goods
that are being used in other parts of the world.
So I don't think it's fair to say
that China's responsible
when we're all benefiting from the products
that are produced there.
I think even today, it's worth thinking
not just about how much is a country emitting,
but how much are they emitting per person?
And I have another visual aid here.
You can pretty clearly see
the highest-intensity emitters
are places like Australia,
the US, Canada, Russia, Saudi Arabia.
China isn't even in the top 10.
It's also a complicated problem
because the well-being of people
is tied to their consumption of energy.
So as long as we're doing that
in a sustainable, cleaner way,
I think we all have to benefit from it.
"Renewable energy is too expensive to be realistic."
Renewable energy is getting cheaper all the time,
even faster than we expected.
And there's a lot of places
where it actually can outcompete some fossil fuel sources.
For example, I believe wind and solar
is more cost-effective than coal
in pretty much the entire United States.
The cost of producing solar panels today
is a fraction of what it was just a decade ago.
I keep going back to India
because that's another region I'm very familiar with.
There are a lot of villages there
that have been provided energy
because they're using solar and wind,
which would not have been possible
if we were still depending upon CO2.
Now, there's still challenges.
We're not going to kind of
be able to switch everything overnight,
but it's like any other technology.
It's getting cheaper over time.
It's getting more efficient.
And the more we kind of invest in it,
then the faster we'll get to the point
that we'll be able to use it for most of our needs.
"Extreme weather isn't caused by global warming."
So, the right question to ask
is not whether an extreme event
would have been possible without warming,
but it's to ask how the event itself
was affected by warming.
For example, a tropical storm or a tropical cyclone
might result in heavier precipitation
because a warmer atmosphere holds more moisture.
And so there's more moisture, more fuel in the storm,
which results in heavier precipitation
and likely more flooding.
I think a good analogy
is a professional athlete on steroids.
Athletes need to have some kind of innate fitness
and ability, but if you go on steroids,
you're a bit more likely to hit a home run.
So CO2 is kind of like
the steroids of the climate system,
and it's just intensifying everything that's already there.
"The temperature record is unreliable."
What do you have to say about that, Ben?
The record we have of warming for the last 150 years
is constructed from basically
thousands of thermometer records from around the world.
Climate scientists often get accused
of modifying the temperature record
to make it look like it's warming more than it actually is.
At least half a dozen groups around the world
who are all independently putting together these records
and estimating the global temperature changes
that we've seen over the last two centuries,
and they're all basically getting the same answer.
All this data is publicly available!
Anybody can go and get this data
and come up with their own calculation.
And the fact is that nobody has shown one
that is credibly different.
"It's too late to do anything about it."
It's easy for us to say,
"Well, it's too late to do anything about it.
Let's throw our hands up and not do anything about it."
But there is a lot we can do about it, both individually
as well as at the international level.
It doesn't have to be a major change,
but reducing our consumption of certain meat products
that are extremely energy-intensive
is one way in which we can affect greenhouse emissions.
The decisions we make today,
we are going to have to deal with,
our children are going to have to live with.
I will never say that people should not recycle
or reduce their car use or eat less meat.
But at the end of the day,
the big lever is just going to be government.
And 'cause the government can set policies
that can incentivize actions.
It's also a weird time to say
that it's too late to do anything about it,
because we're at a point in time
when we have so much information.
There are people working on technologies
to address climate change
and to make our environment cleaner and better.
So this is not a time for us to put our hands up.
It's our time to take action.
Climate change itself is not pass-fail.
Keeping warming to three degrees
is better than four degrees.
Keeping warming to two and a half degrees
is better than three degrees.
Keeping warming to two degrees
is better than all of those things.
We're all stuck here,
so we should try to figure out
how we can make it the best planet we can.
Climate change is a global problem,
and it's going to require a global solution
and people to actually kind of work together.