Multiple Benefits Include
Improved Air Quality and Human Health, Higher
Crop Yields, Reduced Rate of Climate Change
in the Near-Term and a Chance to Slow Serious
Melting of the Arctic
New UNEP-WMO Assessment Complements Urgent
Action Needed to
Cut CO2 Emissions Under UN Climate Treaty
Bonn, 14 June 2011 - - Fast action on pollutants
such as black carbon, ground level ozone
and methane may help limit near term global
temperature rise and significantly increase
the chances of keeping temperature rise
below 2 degrees Celsius, and perhaps even
1.5 degrees C, a new assessment says.
Protecting the near-term
climate is central to significantly cutting
the risk of "amplified global climate
change" linked with rapid and extensive
loss of Arctic ice on both the land and
at sea.
Fast action might also
reduce losses of mountain glaciers linked
in part with black carbon deposits while
reducing projected warming in the Arctic
over the coming decades by two thirds.
The scientists behind
the assessment, coordinated by the United
Nations Environment Programme (UNEP) and
the World Meteorological Organization (WMO),
also point to numerous public health and
food security opportunities above and beyond
those linked with tackling climate change.
Big cuts in emissions
of black carbon will improve respiratory
health; reduce hospital admissions and days
lost at work due to sickness, says the assessment
whose Secretariat is provided by the Stockholm
Environment Institute. Indeed close to 2.5
million premature deaths from outdoor air
pollution could on average be avoided annually
world-wide by 2030 with many of those lives
saved being in Asia, it is estimated.
Big cuts in ground level
ozone could also contribute to reduced crop
damage equal to between one to four per
cent of the annual global maize, rice, soybean
and wheat production.
Cutting these so-called
'short-lived climate forcers' can have immediate
climate, health and agricultural benefits,
the report concludes. This is because, unlike
carbon dioxide (CO2) which can remain in
the atmosphere for centuries black carbon
for example only persists for days or weeks.
The researchers however
also underline the fact that while fast
action on black carbon and ground level
ozone could play a key role in limiting
near-term climate, immediate and sustained
action to cut back CO2 is crucial if temperature
rises are to be limited over the long-term.
It is the combination
of action on short-lived climate forcers
and long-lived greenhouse gases which improves
the chances of keeping below the 2 degree
target throughout the 21st Century.
The findings, released
today in Bonn, Germany during a meeting
of the UN Framework Convention on Climate
Change (UNFCCC) have been compiled by an
international team of more than 50 researchers
chaired by Drew Shindell of the National
Aeronautics and Space Administration (NASA).
Achim Steiner, UN Under-Secretary
General and UNEP Executive Director, said:
"There are now clear, powerful, abundant
and compelling reasons to reduce levels
of pollutants such as black carbon and tropospheric
ozone along with methane: their growing
contribution to climate change being just
one of them".
"This assessment
underlines how the science of short lived
climate forcers has evolved to a level of
maturity that now requires and requests
a robust policy response by nations. The
experts spotlight how a small number of
emission reduction measures- targeting for
example recovery of methane in the coal,
oil and gas sectors through to the provision
of cleaner burning cook stoves; particle
traps for diesel vehicles and the banning
of open burning of agricultural wastes-
offer dramatic public health, agricultural,
economic and environmental benefits,"
he added.
The UNEP/WMO Integrated
Assessment of Black Carbon and Tropospheric
Ozone suggests that action could be catalyzed
through not only the UN climate convention
process but also via, for example, strengthening
existing national and regional air quality
agreements.
Michel Jarraud, Secretary-General
of the WMO, said: "Most attention is
focused on reducing the main greenhouse
gas, CO2 , to combat climate change. However
recent years it has become clear that a
range of other pollutants such as black
carbon and tropospheric ozone are aggravating
the challenge".
"This report underlines
the need for a stronger observational basis
and research effort to increase scientific
understanding of the role of these other
pollutants in the changing climate system.
WMO's Global Atmosphere Watch Programme
is addressing these challenges as a priority,"
he added.
Drew Shindell of NASA's
Goddard Institute for Space Studies said:
"This report has brought clarity to
the complexity of the heating and cooling
effects of a range of pollutants and uses
the science to show that there are clear
and concrete measures that can be undertaken
to help protect the global climate in the
short to medium term".
"Perhaps the most
intriguing link is between emissions of
methane and the formation of tropospheric
ozone. Methane is a powerful greenhouse
gas in its own right, but it has emerged
that it is also triggering a great deal
more global warming by contributing to the
formation of significant levels of ground
level ozone?indeed more than was previously
supposed. The win-win here for limiting
climate change and improving air quality
is self-evident and the ways to achieve
it have become far clearer as a result of
this assessment," he added.
Today the Government
of Sweden announced support for a comprehensive
and forward-looking policy assessment to
assist governments on the next steps towards
fast action on short lived climate forcers.
This is line with Sweden's strategy on SLCFs
and its policy to integrate climate change
and air pollution policies.
The work, to be coordinated
by UNEP, is expected to be ready in advance
of the next Climate Convention meeting scheduled
later in the year in Durban, South Africa.
The Pollutants Assessed
Black carbon is a major
component of soot and is formed from the
incomplete combustion of fossil fuels, wood
and biomass. Key sources include emissions
from cars and trucks; cookstoves; forest
fires and some industrial facilities.
It affects the climate
by intercepting and absorbing sunlight and
darkens snow and ice when deposited, while
also influencing cloud formation. It is
also a health hazard.
Tropospheric ozone is
a major component of urban smog, is a powerful
greenhouse gas and air pollutant harmful
to human health and ecosystems.
The threefold increase
in concentrations in the northern hemisphere
in the past 100 years has made it the third
most important global greenhouse gas.
Tropospheric ozone is
formed from other gases including methane?itself
a potent greenhouse gas emitted from sources
such as waste tips, livestock and the oil
and gas industry.
How the Study was Carried
Out
Both black carbon and
the gases that form tropospheric or ground
level ozone are typically co-emitted with
other gases and particles, some of which
cause warming and others that cause cooling.
A relatively small selection
of policy measures were chosen from around
2,000 separate measures. The impact of measures
likely to reduce global warming, which have
a large potential for emission reductions
and provide air quality and other benefits
were modeled out to 2070.
Measures for Significantly
Reducing Black Carbon and Ground Level Ozone
Nine actions are pin
pointed in the assessment for black carbon,
all of which could be undertaken today including:-
*Diesel particle filters
for vehicles as part of combined standards
on vehicle emissions and fuels
*Replacing wood burning stoves in developed
countries with pellet stoves and boilers
using fuel from recycled wood and sawdust
*Clean-burning biomass stoves for cooking
and heating in developing countries
*Banning open burning of agricultural wastes
*Replacing traditional brick kilns with
vertical shaft and Hoffman kilns
Seven actions are pinpointed for addressing
ground level ozone which hinge on addressing
methane emissions including:-
*Encouraging composting and other measures
to curb organic wastes going to landfill
*Upgrading water treatment works to include
gas recovery
*Measures to cut methane emissions from
the coal, oil and gas industries, including
Cutting leaks from long distance gas pipelines
Promoting anaerobic digestion of manure
from cattle and pigs
*Intermittent aeration of continuously flooded
paddy fields
Notes to Editors
Key Findings from the
Integrated Assessment of Black Carbon and
Tropospheric Ozone Assessment in Detail
Without measures to
curb climate change emissions, temperatures
are projected to rise on average by a further
1.3 degrees C by mid-century "bringing
the total warming from pre-industrial levels
to about 2.2 degrees C.
Arctic
"Near term warming
may occur in sensitive regions and could
cause essentially irreversible changes such
as loss of Arctic land-ice, release of methane
and CO2 from Arctic permafrost and species
loss,' says the assessment.
"Reducing the near-term
rate of warming hence decreases the risk
of irreversible transitions that could influence
the global climate system for centuries,"
it adds.
*Fully implementing
the measures outlined in the assessment
in respect to black carbon, tropospheric
ozone and methane could roughly halve (around
0.5 degrees C) the projected global temperature
rise between now and the 2030s
*Such measures could
reduce warming in the Arctic by around 0.7
degrees C in 2040, or roughly two-thirds
of the estimated warming
Glaciers
Cutting black carbon
levels in high mountain regions such as
the Himalayas and the Tibetan Plateau could
slow the melting rates of glaciers-in part
because soot deposits increase the absorption
of sunlight- and reduce the risk of the
formation of glacial lakes and associated
catastrophic outburst floods.
In the high valleys
of the Himalayas, for example, black carbon
levels can now be as high as in a mid-sized
city
Impacts on the Asian
Monsoon and Africa rainfall
Increasing concentrations
of particles like black carbon may also
affect the timing and patterns of the Asian
monsoon with important implications for
"human well-being because of changes
in water supply and agricultural productivity,
drought and flooding," says the assessment.
Implementation of black
carbon measures could also lead to a considerable
reduction in the disruption of traditional
rainfall patterns in Africa
Health Benefits
Ground-level ozone and
fine particles, including black carbon,
are linked with premature deaths, primarily
heart disease and lung cancer alongside
other illnesses such as bronchitis and low
birth weight
Implementing the recommended
measures would benefit public health especially
in Asia and also in Africa.
Crop Benefits
Both ground-level ozone
and black carbon can affect the health,
growth and productivity of crops, trees
and other plants.
Implementing the measures
to reduce methane and thus ground-level
ozone would assist in avoiding annual yield
losses of about 25 million tonnes of four
staple crops
Significantly curbing
black carbon emissions would account for
a further 25 million tonnes of avoided crop
losses annually
The summary for decision
makers and full UNEP/WMO Integrated Assessment
of Black Carbon and Tropospheric Ozone report
can be found at : http://www.unep.org/dewa/Portals/67/pdf/BlackCarbon_SDM.pdf
The UN Climate Change
Conference June 2011 http://unfccc.int/2860.php
UNEP's work on climate
change http://www.unep.org/climatechange/
WMO, the U.N. system's
authoritative voice on weather, water and
climate, is at www.wmo.int
