- When world leaders and activists talk
about combating climate change...
- Mitigating CO2 emissions. - Carbon-free economy.
- Carbon neutrality, net zero. - ...
Their main goal is to reduce greenhouse gas emissions.
Those gasses from cars, oil refineries, cows,
etcetera, all trap heat
and lead to warming temperatures,
causing more devastating natural disasters and drought,
and melting glaciers, leading to sea level rise.
According to the August 2021 UN Climate Report,
the average global temperature has already been predicted
to soon reach an increase of 1.
5 degrees Celsius,
only stopping there if countries make immediate,
large-scale reductions.
But do we have a clear picture of the world's emissions?
- The UN has asked countries across the world
to report greenhouse emissions
within their countries to the UN,
and they put that in a centralized database.
We developed a model
which would represent 2019 numbers for countries
that didn't report data from that year.
And at that point, we were able to tally this up
and come up with a global number.
- What we found is that there is
a pretty significant gap between the two.
- The Post found that total global emissions
are significantly undercounted, and that there is a 16-23% gap
in unclaimed emissions from 2019.
Figuring out why the numbers are off
might come down to a basic question --
how are countries measuring their emissions?
- The most simple equation that many countries use
is to take an activity, like, you know,
how many cows are there on pastures in your country --
that would be your activity data,
and then multiply it by what's called an emissions factor.
So, per cow, we think that this much methane
is belched into the air in a year,
and then that multiplication, more or less,
is your emission number.
Obviously, that is a huge oversimplification
of what is actually going on.
Cows are not all the same size.
They do not all emit the same amount of methane.
Plus, that's assuming you have the number of cows
correct to begin with.
So this is the process by which a lot of errors
inevitably get introduced.
- The alternative to using the UN's ground-up method
is the top-down model, which uses satellite data.
- Scientists can now take satellite measurements
of emissions over a territory of at least a large country,
or atmospheric measurements,
or both and run them through a computer simulation
and attribute where they came from.
- One of the drawbacks of that method is that not --
it doesn't help capture every country,
every small nation across the globe,
and that's one of the biggest challenges
that we faced in trying to find a global number.
- Currently, countries divide their land
into managed or unmanaged areas.
- Land gets divided in the UN's system into forest,
grassland, croplands, settlements -- those are cities.
A lot of countries claim that the managed area is sucking
a lot of carbon out of the air rather than emitting it,
and so that can then be applied to lower the total emissions.
- But not all countries use the same approach.
- The US, for instance, almost the entire country
is considered managed land.
They can take any reductions from the land
and apply it into their net emissions.
But Australia does it differently.
Canada does it differently.
So there isn't an equal playing field for all these countries.
- And it's not a simple equation.
Some land areas, like rainforests, are carbon sinks.
- The reason land is so tough is that, "A",
it's full of scientific uncertainties,
so what is actually happening with how forests,
for instance, pull carbon in but then give it up again
if they, you know, face drought,
or if they're chopped down, or if they burn.
- Another issue is that the numbers are self-reported,
with little accountability.
- [speaking in French] -World leaders have
repeatedly committed to lowering emissions --
in Kyoto in 1997, and in Paris in 2015.
- Under that agreement, that was the first time
the world got organized to do something about climate change,
and really, they all are driven by the will
and the participation of the countries.
You know, if you don't do this, there's no punishment,
except for sort of political --
being unpopular, being criticized.
There's nothing other than that.
- We're already in a crucial moment,
where greenhouse gas emissions need to be drastically reduced.
- If we are wrongly calculating the emissions today,
our policies that we should be adhering to
for the next 50 years
are going to be based on these incorrect numbers.
So 50 years from now,
we are going to be in a much worse place
than our models or predictions are foreseeing.