What are climate pollutants

Headline: Air pollution and climate change

Air pollution: a major health risk worldwide

At the first WHO global conference on air pollution and health, WHO Director-General Dr. Tedros Adhanom Ghebreyesus describes air pollution as a "silent health crisis". Around 7 million premature deaths annually are caused by air pollution, of which 4 million are due to outdoor air pollution. Air pollution not only shortens life expectancy, but can also have a negative impact on our everyday lives, as it causes respiratory diseases and leads to absenteeism at work and at school. Children are particularly vulnerable to the effects of air pollution: exposure to air pollution in early childhood, when the lungs are still developing, can lead to decreased lung function, which continues into adulthood.

Effects of short-lived climate-affecting pollutants on health and ecosystems

Soot (black carbon, BC) is a component of fine particulate matter (PM2.5). Particulate matter is the air pollutant most harmful to human health and it is the leading cause of deaths from air pollution. Research suggests that soot is likely one of the constituents of PM2.5 with the greatest health impact.

Methanes (CH4) has no immediate health effects, i.e. inhaling methane in its typical concentration in the ambient air is not harmful to health. However, methane has very significant indirect effects on human health because it is a precursor to ground level ozone (O3, also known as tropospheric ozone), which causes asthma and other respiratory diseases and contributes to premature deaths from air pollution. Ozone also damages plants and results in annual crop losses of 11-18 billion dollars.

Climate change: we have to take action against air pollution and CO2

In order to meet the goal of the Paris Agreement of limiting global warming to 1.5 (or even 2) degrees Celsius, a rapid reduction in CO2 emissions is absolutely essential, but it is not enough on its own. The IPCC special report on 1.5 ° C global warming emphasizes that a drastic reduction in emissions of climate-relevant substances other than CO2, in particular the air pollutants methane and soot, is also of the utmost importance. Decarbonising the economy in general will reduce emissions of both CO2 and air pollutants, but phasing out fossil fuels alone is not sufficient for either air quality or the climate. First, emissions from other sectors also play an important role: For example, methane and soot emissions from agriculture have a significant impact on health and the climate, while emissions of coolants (especially fluorocarbons, HFC) from the cooling sector are extremely potent in heating the climate. Second, it is important to consider both CO2 and air pollutants when designing and selecting climate and air quality measures to ensure that the desired benefits can actually be achieved. For example, certain technologies that are touted as climate-friendly - such as the combustion of biomass and other biofuels to heat homes or in traffic - release more particulate matter, including soot, than the technology that has been replaced and thus continue to cause damage to health and potential climate impacts.

If we want to achieve the goals of the Paris Agreement, then emissions of other climate-affecting pollutants such as methane, soot and ground-level ozone must be reduced as well as carbon dioxide emissions. These reductions would benefit the climate and promote sustainable development because they improve the health of the population through increased air quality, prevent crop losses and ensure that we avoid climate tipping points that would have drastic long-term consequences and hinder efforts to adapt to climate change .

Multiple benefits for climate, air quality, health and sustainable development

In addition to meeting the temperature targets of the Paris Agreement, drastic reductions in methane, soot and ground-level ozone have other key benefits for sustainable development: they protect health and prevent premature deaths by improving air quality; you avoid millions of tons of crop losses annually; and they can prevent the climate tipping points that can exacerbate long-term climate impacts and make adaptation to climate change difficult, especially for the poor and most vulnerable. Through combined measures for climate protection and against air pollution, we have the opportunity to use the synergies between the climate goals of the Paris Agreement and the Sustainable Development Goals of the United Nations to improve life today and limit future global warming.

IASS research on air pollution and climate change

Air quality modeling for policy advice (AQ) deals with basic research in order to understand the effects of emission sources on the pollution level of the ambient air and the associated consequences. The primary method is numerical modeling, a particular focus of the group is the long-distance transport of ground-level ozone. The group works with the Task Force on Hemispheric Transport of Air Pollution, which provides science-based advice to support the Convention on Long-Range Transboundary Air Pollution.

ClimAct examines the potentials and limits of an integrated approach to air quality and climate in the context of the Paris Agreement and the Sustainable Development Goals, in particular through its participation in and engagement with the Climate and Clean Air Coalition (CCAC), a voluntary transnational partnership that pursues the goal to reduce global warming in the short term and to improve air quality through measures against short-lived climate-affecting pollutants.

ClimPol With his research work supports transformations towards a more integrated policy on climate change and air quality. The project deals with a wide variety of issues relating to air quality in urban areas and examines the relationships between air pollution, climate change and mobility. The research team also draws public attention to these issues by stimulating dialogue between politicians and actors from civil society and academia.

SusKat aims to reduce air pollution levels in Nepal; it does this by improving scientific knowledge, identifying effective measures and making politicians and the public more aware of the problem and its solutions. The project is now in its third phase and is currently engaged in capacity building and stakeholder engagement to support the implementation of the most promising containment measures.