Potent,
climate-warming gases are being emitted into the atmosphere but are not being
recorded in official inventories, a
BBC investigation
has found.
Air monitors in Switzerland
have detected large quantities of one gas coming from a location in Italy.
However, the Italian
submission to the UN records just a tiny amount of the substance being emitted.
Levels of some emissions
from India and China are so uncertain that experts say their records are plus
or minus 100%.
These flaws posed a bigger
threat to the Paris climate agreement than US President Donald Trump's
intention to withdraw, researchers told BBC Radio 4's
Counting Carbon
programme.
Bottom-up records
Among the key provisions of
the Paris climate deal, signed by 195 countries in December 2015, is the
requirement that every country, rich or poor, has to submit an inventory of its
greenhouse-gas emissions every two years.
Under UN rules, most
countries produce "bottom-up" records, based on how many car journeys
are made or how much energy is used for heating homes and offices.
But
air-sampling programmes that record actual levels of gases, such as those run
by the UK and Switzerland, sometimes reveal errors and omissions.
In 2011, Swiss scientists
first
published their data
on levels of a gas called HFC-23
coming from a location in northern Italy.
Between 2008 and 2010, they
had recorded samples of the chemical, produced in the refrigeration and air
conditioning industries, which is 14,800 times more warming to the atmosphere
than CO2.
Now the scientists, at the
Jungfraujoch Swiss air monitoring station, have told the BBC the gas is still
going into the atmosphere.
"Our estimate for this
location in Italy is about 60-80 tonnes of this substance being emitted every
year. Then we can compare this with the Italian emission inventory, and that is
quite interesting because the official inventory says below 10 tonnes or in the
region of two to three tonnes," said Dr Stefan Reimann, from the Swiss
Federal Laboratories for Materials Science and Technology.
"They actually say it
is happening, but they don't think it is happening as much as we see.
"Just to put it into
perspective, this greenhouse gas is thousands of times stronger than CO2.
"So, that would be
like an Italian town of 80,000 inhabitants not emitting any CO2."
The Italian environment
agency told the BBC its inventory was correct and complied with UN regulations
and it did not accept the Swiss figures.
Another rare warming gas, carbon tetrachloride, once
popular as a refrigerant and a solvent but very damaging to the ozone layer,
has been banned in Europe since 2002.
But Dr Reimann told Counting Carbon: "We still
see 10,000-20,000 tonnes coming out of China every year."
"That is something that shouldn't be there.
"There is actually no Chinese inventory for these
gases, as they are banned and industry shouldn't be releasing them
anymore."
China's approach to reporting its overall output of
warming gases to the UN is also subject to constant and significant revisions.
Its last submission ran to about 30 pages - the UK's,
by contrast, runs to several hundred.
Back in 2007, China simply refused to accept, in
official documents, that it had become the largest emitter of CO2.
"I was working in China in 2007," said Dr
Angel Hsu, from Yale University.
"I would include a citation and statistics that
made this claim of China's position as the number one emitter - these were just
stricken out, and I was told the Chinese government doesn't yet recognise this
particular statistic so we are not going to include it."
A report in 2015 suggested one error in China's statisticsamounted to 10% of global emissions in 2013.
The BBC investigation also discovered vast
uncertainties in carbon emissions inventories, particularly in developing
countries.
Methane, the second most abundant greenhouse gas after
CO2, is produced by microbe activity in marshlands, in rice cultivation, from
landfill, from agriculture and in the production of fossil fuels.
Global levels have been rising in recent years, and
scientists are unsure why.
For a country such as India, home to 15% of the
world's livestock, methane is a very important gas in their inventory - but the
amount produced is subject to a high degree of uncertainty.
"What they note is that methane emissions are
about 50% uncertain for categories like ruminants, so what this means is that
the emissions they submit could be plus or minus 50% of what's been
submitted," said Dr Anita Ganesan, from the University of Bristol, who has
overseen air monitoring research in the country.
"For nitrous oxide, that's 100%."
There are similar uncertainties with methane emissions
in Russia, of between 30-40%, according to scientists who work there.
"What we're worried about is what the planet
experiences, never mind what the statistics are," said Prof Euan Nisbet,
from Royal Holloway, University of London.
"In the air, we see methane going up. The warming
impact from that methane is enough to derail Paris."
The rules covering how countries report their
emissions are currently being negotiated.
But Prof Glen Peters, from the Centre for
International Climate Research, in Oslo, said: "The core part of Paris
[is] the global stock-takes which are going to happen every five years, and
after the stock-takes countries are meant to raise their ambition, but if you
can't track progress sufficiently, which is the whole point of these
stock-takes, you basically can't do anything.
"So, without good data as a basis, Paris
essentially collapses. It just becomes a talkfest without much progress."
* Matt McGrath is a BBC Environment correspondent
(bbc.com)