Suchergebnisse

Der Alpenraum soll sich zu einer Modellregion für grünes Wirtschaften entwickeln. Das Hintergrundpapier beschreibt wichtige Aspekte der Entwicklung der grünen Wirtschaft im Alpenraum anhand der folgenden vier Themenfelder: kohlenstoffarme Wirtschaft und Klimaanpassung, ressourceneffiziente Wirtschaft, Ökosystemleistungen und Naturkapital sowie Lebensqualität und Wohlbefinden. Dies wird ergänzt durch aktuelle Informationen aus relevanten Projekten unter Beteiligung des Umweltbundesamtes.

On 16 September 1987, 24 States and the European Community signed the Montreal Protocol. It initiated the mandatory phase-out of chlorofluorocarbons (CFCs) and thus stopped the further destruction of the ozone layer by these substances. The switch to alternatives to CFCs with their high global warming potential also contributes to climate protection. Due to the worldwide implementation of the Montreal Protocol, ozone-depleting substances such as CFCs are hardly used today. Atmospheric concentrations of these substances are slowly declining due to natural decomposition processes and the size of the "ozone hole" over Antarctica is also becoming smaller. Because CFCs and other halogenated substances are also very effective greenhouse gases that heat up the climate up to 14,000 times more effective than carbon dioxide (CO2), the Montreal Protocol has contributed not only to protecting the ozone layer but also to climate protection. With the Kigali Amendment for the worldwide phase-down of climate-damaging hydrofluorocarbons (HFCs), which has been agreed on in October 2016, the Montreal Protocol was extended to a new group of substances. In a background paper on the 30th anniversary of the Montreal Protocol, the German Environment Agency describes the history of this important international agreement from the discovery of the "ozone hole" to its signing and implementation. In addition, the paper provides information on the HFC use today and on environmentally friendly substitutes and techniques, especially for refrigeration and air conditioning.

Mit der Unterzeichnung des Montrealer Protokolls wurde vor 30 Jahren die Grundlage zum Schutz der Ozonschicht gelegt. Der Abbau der Ozonschicht durch Fluorchlorkohlenwasserstoffe (FCKW) war eines der drängendsten Umweltprobleme der 1980er Jahre. Der Ausstieg aus den FCKW ist weitestgehend abgeschlossen, trotzdem stellen die teilfluorierten Kohlenwasserstoffe (HFKW), die die FCKW vor allem als Kältemittel in der Klima- und Kältetechnik bis heute ersetzen, ein Problem für das Klima dar. Das Hintergrundpapier blickt zurück auf Entstehung und Weiterentwicklung des Montrealer Protokolls, illustriert die Emissionssituation von FCKW und HFKW und beschreibt Alternativen zur Verwendung von HFKW.

The Alpine area wants to turn into a green economy model region. The background paper describes important aspects for a development of a green economy in the Alps in four topic areas: Low-carbon economy and adaptation to climate change, resource-efficient economy, ecosystem services and natural capital, quality of life and well-being. To complement this, current information from relevant projects of the German Environment Agency is added.

Abstract
Background
The implementation of emission mitigation policies in Europe over the last two decades has generally improved the air quality, which resulted in lower aerosol particle mass, particle number, and black carbon mass concentration. However, little is known whether the decreasing particle concentrations at a lower-altitude level can be observed in the free troposphere (FT), an important layer of the atmosphere, where aerosol particles have a longer lifetime and may affect climate dynamics. In this study, we used data from two high-Alpine observatories, Zugspitze-Schneefernerhaus (ZSF) and Jungfraujoch (JFJ), to assess the long-term trends on size-resolved particle number concentrations (PNCs) and equivalent black carbon (eBC) mass concentration separated for undisturbed lower FT conditions and under the influence of air from the planetary boundary layer (PBL) from 2009 to 2018.

Results
The FT and PBL-influenced conditions were segregated for both sites. We found that the FT conditions in cold months were more prevalent than in warm months, while the measured aerosol parameters showed different seasonal patterns for the FT and PBL-influenced conditions. The pollutants in the PBL-influenced condition have a higher chance to be transported to high-altitudes due to the mountainous topography, leading to a higher concentration and more distinct seasonal variation, and vice versa. The long-term trends of the measured aerosol parameters were evaluated and the decreased aerosol concentrations were observed for both FT and PBL-influenced conditions. The observed decreasing trends in eBC concentration in the PBL-influenced condition are well consistent with the reported trends in total BC emission in Germany and Switzerland. The decreased concentrations in the FT condition suggest that the background aerosol concentration in the lower FT over Central Europe has correspondingly decreased. The change of back trajectories in the FT condition at ZSF and JFJ was further evaluated to investigate the other possible drivers for the decreasing trends.

Conclusions
The background aerosol concentration in the lower FT over Central Europe has significantly decreased during 2009–2018. The implementation of emission mitigation policies is the most decisive factor and the decrease of the regional airmass occurrence over Central Europe also has contributed to the decreasing trends.

Anthropogenic emissions are a dominant contributor to air pollution. Consequently, mitigation policies have attempted to reduce anthropogenic pollution emissions in Europe since the 1990s. To evaluate the effectiveness of these mitigation policies, the German Ultrafine Aerosol Network (GUAN) was established in 2008, focusing on black carbon and sub-micrometer aerosol particles, especially ultrafine particles. In this investigation, trends of the size-resolved particle number concentrations (PNC) and the equivalent black carbon (eBC) mass concentration over a 10-year period (2009–2018) were evaluated for 16 observational sites for different environments among GUAN. The trend analysis was done for both, the full-length time series and on subsets of the time series in order to test the reliability of the results. The results show generally decreasing trends of both, the PNCs for all size ranges as well as eBC mass concentrations in all environments, except PNC in 10–30 nm at regional background and mountain sites. The annual slope of the eBC mass concentration varies between −7.7 % and −1.8 % per year. The slopes of the PNCs varies from −6.3 % to 2.7 %, −7.0 % to −2.0 %, and −9.5 % to −1.5 % per year (only significant trends) for 10–30 nm, 30–200 nm, and 200–800 nm particle diameter, respectively. The regional Mann-Kendall test yielded regional-scale trends of eBC mass concentration, N [30–200] and N [200–800] of −3.8 %, −2.0 % and −2.4 %, respectively, indicating an overall decreasing trend for eBC mass concentration and sub-micrometer PNC (except N [10–30] ) all over Germany. The most significant decrease was observed on working days and during daytime in urban areas, which implies a strong evidence of reduced anthropogenic emissions. For the seasonal trends, stronger reductions were observed in winter. Possible reasons for this reduction can be the increased average ambient temperatures and wind speed in winter, which resulted in less domestic heating and stronger dilution. In addition, decreased precipitation in summer also diminishes the decrease of the PNCs and eBC mass concentration. For the period of interest, there were no significant changes in long-range transport patterns. The most likely factors for the observed decreasing trends are declining anthropogenic emissions due to emission mitigation policies of the European Union.