The German environmental and consumer associations NABU, BUND, VCD and DUH started the „Soot free for the climate!“ campaign in March 2009 to address the climatic effect of black carbon. The campaign will raise the subject of the climatic effect of black carbon in political and social discussion, name the essential political decisions and claim its implementation. This alliance of organisations will be able to offer a broad competence in media and policy. The largest advantage of this alliance is its local and regional presence.

Figure 1: Surface temperature anomaly (°C) in 2008 (Base period: 1951-1980). Source: James E. Hansen, 2008.

Arctic warming has increased dramatically. A considerable temperature increase can be ascertained especially in the winter months. During the first seven years of this century global temperature has increased by about 0.54 °C on average compared to the reference time period 1951 – 1980. During the same time period, the temperature in the arctic rose by more than 2 °C. In 2008, the Arctic warming was even greater. While the average global temperature rose by about 0.44 °C, compared to the reference period, the Arctic’s temperature was 3.5 °C higher (see Figure 1).

This rise in atmospheric temperature is contributing to a sea ice melt that is occurring much faster than previously thought possible. If this melting continues, one of the consequences of this is a release of carbon dioxide and methane from the melting perma-frost soil. Ice sheet warming, such as occurring in Greenland, will also contribute to sea level rise, and rising seas will have worldwide effects. These changes are threatening to create an irreversible situation (the so called “tipping point”). This has unforeseeable consequences not only for the local region, but also for the global climate. Scientists, like Dr. James E. Hansen from the NASA Goddard Institute for Space Studies, asserted that the impact from Black Carbon contributes to these climate changes.

Black carbon (soot) particles, which result from fossil fuels and biomass, have a threefold damaging effect:

• Black Carbon absorbs radiating heat from the sun and warms its direct environment (direct effect),

• Black Carbon interacts with clouds and affects rainfall patterns (indirect effect).

• Black Carbon falls onto snow and ice and changes the overall reflectivity of those surfaces (albedo effect) and accelerates the onset of spring melt.

The warming effect of soot in the Arctic is reflected by an earlier and increased melting of ice and snow surfaces in spring and the deeper thawing of permafrost soils. This again strengthened the effects.

European sources contribute to the burden of Black Carbon reaching the arctic. As shown in the following figure (see left Figure 3: How Air Pollution reaches the Arctic), soot emissions from Europe are carried by the prevailing wind currents of the northern hemisphere either over Siberia or directly to the Arctic and are deposited there. There are also particles from North America
and South East Asia in the Arctic Modelling and measurement work is underway to better pinpoint the contribution of Black Carbon by region and season.

There are a lot of different sources of soot particles worldwide. Most of them are caused by forest and crop waste burning and use of bio-based fuels for residential cooking and heating. Diesel on and off road is responsible for roughly 25% of non-fire sources of emissions. The warming potential of black carbon in the arctic region is essentially down to where the emission takes place.

Figure 4: Soot emissions: near arctic mainly transport, industry, some residential, Source: Tami Bond, 2009.

The graph above (Figure 4) shows that traffic is the major source of black carbon emissions between 40th and 50th northern latitude, which is the location of Central Europe. One reason for this is the large proportion of diesel vehicles in Europe. Diesel particulate filters, which can be installed on new and in-use vehicles, are able to reduce black carbon emissions by up to 99%. Unfortunately, there has been only minimal installation of these effective filters so far. This means that diesel engines – from lorries and busses, ships and construction machines – are emitting unfiltered exhaust. Installing these filters will result not only in cleaner air, with associated health benefits, but also in less warming and melting of the arctic ice. These climate benefits will be felt in both globally and in the Arctic. Hence the associations concentrate in the campaign “soot free for the climate” on diesel emissions of transportation sector. Black carbon particles are short lived staying in the atmosphere for no more than a week. That short lifetime, particularly when compared to some of the longer-lived greenhouse gases, such as carbon dioxide, means reduction of black carbon can lead to a quick climate response. A strategy with the best hope for climate stabilization would capitalize on a two-pronged approach to both short and long-lived pollutants. A focus on the short-lived pollutants, including black carbon, offers fast action and the focus on reducing long-lived gases is needed to maintain global temperatures at levels believed to be safe.

Aim of this campaign is the reduction of diesel emissions of vehicles (cars, lorries, busses) and “off-road”-engines of diesel powered rail vehicles, ships and construction machines. All diesel engines have to be fitted with effective particle filters. This campaign is addressed to the European Union, the German federal government, the German Laender and local authorities.

The associations call for:

• Reducing black carbon in the European Union by 100 % by 2020. This is technically feasible, as there are already numerous providers for filter systems and lowemission vehicles in Europe. So a requirement for exhaust gas treatments would benefit the European market.

• Passage of a federal reduction aim for diesel emissions, based on its climate protection targets.

• Setting ambitious environmental standards by German Laender and local authorities aimed at clean up of the public transport fleet.

• Designating local environmental zones or advance existing environmental zones that restrict all unfiltered engines.

• Expansion of the cycle traffic.