EUCAARI was a EU 6th Framework Programme Integrated Project on aerosol, cloud, climate and air quality interactions
EUCAARI has and a hugely significant impact on atmospheric aerosol and climate research, on aerosol measurement technologies and techniques, on knowledge transfer, and on mitigation strategies relating to air pollution – climate change interactions. The main impact has come via quantification the effect of aerosols on the planet’s radiative balance to understand future climate change. As an underpinning and critical issue, during EUCAARI, the integration of European atmospheric research, with a particular focus on aerosols, air pollution, atmospheric composition and climate change has improved over and above the sum of the individual parts of the project. This underpinning paves the way for more critically and informed research and assessments into the future.
From a technological perspective, EUCAARI has been developed new aerosol measurement instruments and has deployed some of the most complex research instruments world wide in, more or less, an operational manner. Such instruments include the cluster spectrometer, deployed annually over extended periods at numerous sites including airborne platforms. Besides the aforementioned instrument, several new instrumental techniques have been developed and utilized in filed and laboratory studies with annual observation of different properties of atmospheric aerosol having been perfor med at between 12-24 different sites to different degrees. EUCAARI has moved highly complex and labour intensive aerosol measurement techniques from research mode to pseudo-operational measurements delivering important data, previously lacking, to stakeholders.
In terms of knowledge transfer, EUCAARI activities includes extensive workshops, seminars, winter and summer schools as well as daily mentoring of students and post doctoral researchers from regions within and beyond Europe.
The improved understanding of regional aerosol concentrations and emissions applies directly for the planning of the European mitigation strategies estimating the cost-efficiency of future emission controls, and the risk-analysis of long-term investments. In EUCAARI we have provided more informed tools, compared to this previously existing, to perform a more informed pollution-impact assessment with a particular emphasis on atmospheric aerosols. The global modeling community has been offered new usable parameterizations from the results of EUCAARI project. Due to the required long computing time complex processes usually need simplification before they can be implemented in global and regional models. The EUCAARI project produced quality controlled parameterizations and investigated the accuracy of essential assumptions used in the models.
However, while the EUCAARI advances are significant, there is a long road to perform a very high-scoring assessment of future climate change and interactions with air quality. The complexity of atmospheric aerosols, and their interactions with clouds, going forward, are still highly complex and warrant significant investment into the future.
Health effects due to air pollution and the potential damage from climate change are probably the two most important environmental problems facing the EU. EUCAARI has quantified the contributions of different anthropogenic and natural sources to the PM10, PM2.5, and ultrafine particle concentrations. Additionally, EUCAARI provided new information on particle hygrosopicity and composition, along with the source apportionment. The project quantified the responses of the aerosol concentrations to changes in emissions of particles and their precursors within and outside Europe. The EUCAARI databank provides knowledge on regional aerosol loadings, hygroscopicity (related to dose of the exposed population) and composition (related to toxicity of the particles) and estimates of how much of the loading is due to long-range transport. EUCAARI also contributed the scientific requirements relating to the European Thematic strategy on Air Pollution, where it was stated that it is necessary to reduce the uncertainties in (i) the knowledge about the sources of PM including their physical and chemical characterization, and whether they are of natural or anthropogenic origin. (ii) the formation of secondary aerosols and how different sources contribute, (iii) the role of long-range transport including intra-hemispheric and global transport for the aerosol load over e.g. Europe; (iv) the links between air pollution and climate change; and (v) the modelling and monitoring of air pollution.
The reduction in uncertainty regarding the aerosol role in climate change allows the EU to achieve a better balance between sustainable economic development and minimal environmental impacts. The involvement of developing countries in the EUCAARI consortium was important both for the quantification of the pollution effects on a global scale but also for helping these countries to develop practical solutions to pollution problems.