Short-lived climate pollutants (SLCPs) are chemicals that remain in the atmosphere
for only a few days or a few decades at the most. They include black carbon particles
(or soot, emitted from wood fires, for example); methane (from oil and gas production
and municipal waste); and tropospheric ozone (from motor vehicles). In addition to
being powerful greenhouse gases, these are dangerous air pollutants, with various
detrimental impacts on human health, agriculture and ecosystems. Yet, there is
little public awareness of the threat these chemicals pose. Actions to reduce SLCPs
might be the only way to slow down global and regional warming in the short term
(10-30 years) and, at the same time, provide immediate air quality benefits. In this
chapter, the author provides examples of initiatives underway to tackle these
pollutants and, at the same time, bring benefits to developing countries. Many of
these measures are low-cost, with initial investments offset by subsequent cost
savings, for example, from reduced fuel use or harnessing of recovered methane.
Global action is needed to raise awareness, enable and encourage national and
regional initiatives, and support the widespread implementation of SLCP control
measures. In March 2012, Sweden, Bangladesh, Canada, Ghana, Mexico and the
United States launched the Climate and Clean Air Coalition, a global partnership to
help developing countries scale up their efforts to combat SLCPs.
Environmental impacts of short-lived climate pollutants
Global carbon dioxide (CO2) emissions continue to increase, reaching a record level of
32 billion tonnes in 2010. We are rapidly approaching concentration levels of long-lived
greenhouse gases that are projected to lead to an annual and global average temperature
increase of more than two degrees Celsius (2 oC) by the year 2100. The best available
scientific knowledge tells us that if we are to have a chance of limiting global climate
warming to 2 oC, we need to decrease global CO2 emissions significantly by 2015, cutting
them by at least 50% by 2050.
Focusing on short-lived climate pollutants (SLCPs, Box 6.1) is an effective way of
mitigating climate change impact in the short term – without losing sight of the
fundamental importance of reducing emissions of long-lived greenhouse gases. SLCPs are,
after CO2, the most important contributors to human (anthropogenic) enhancement of the
global greenhouse effect. The latest scientific evidence confirms that reducing SLCPs could
have a substantial effect on climate change within 10 to 30 years, which is indispensable if
we are to limit global warming to 2 °C by 2100 (UNEP, 2011a).
Short-lived climate pollutants are also dangerous air pollutants, with various detrimental
impacts on human health, agriculture and ecosystems (Box 6.2). According to a recent
study carried out by the United Nations Environment Programme (UNEP, 2011a), broad
implementation of 16 existing measures to reduce emissions of SLCPs through 2030 could
have the following benefits:
● 4 million premature deaths resulting from outdoor air pollution and a further 1.6 million
deaths resulting from indoor air pollution could be avoided each year.
● Annual harvest losses of 52 million tonnes per year of rice, maize, soya beans and wheat
could be avoided thanks to lower concentrations of ground-level ozone.
● Global warming could be reduced by up to 0.5 °C by 2050; by 2040, warming in the Arctic
could be reduced by 0.7 °C.
In many developing countries, the need to abate SLCP emissions is vital, especially for
health and food production. At the same time, developing countries have the least
financial resources to carry out abatement actions. This is why it is particularly important
to find actions that can actually save money. In view of the additional savings that can be
made in the areas of public health and food production, this offers a strong argument for
SLCP abatement measures to be integrated into a country’s development and poverty
reduction strategy
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