The present investigation, carried out as a case study in a typical major city situated in a European coal combustion region (Krakow, Poland), aims at quantifying the impact on the urban air quality of residential heating by coal combustion in comparison with other potential pollution sources such as power plants, industry, and traffic. Emissions were measured for 20 major sources, including small stoves and boilers, and the particulate matter (PM) was analyzed for 52 individual compounds together with outdoor and indoor PM10 collected during typical winter pollution episodes. The data were analyzed using chemical mass balance modeling (CMB) and constrained positive matrix factorization (CMF) yielding source apportionments for PM10, B(a)P, and other regulated air pollutants namely Cd, Ni, As, and Pb. The results are potentially very useful for planning abatement strategies in all areas of the world, where coal combustion in small appliances is significant. During the studied pollution episodes in Krakow, European air quality limits were exceeded with up to a factor 8 for PM10 and up to a factor 200 for B(a)P. The levels of these air pollutants were accompanied by high concentrations of azaarenes, known markers for inefficient coal combustion. The major culprit for the extreme pollution levels was demonstrated to be residential heating by coal combustion in small stoves and boilers (>50% for PM10 and >90% B(a)P), whereas road transport (<10% for PM10 and <3% for B(a)P), and industry (4-15% for PM10 and <6% for B(a)P) played a lesser role. The indoor PM10 and B(a)P concentrations were at high levels similar to those of outdoor concentrations and were found to have the same sources as outdoors. The inorganic secondary aerosol component of PM10 amounted to around 30%, which for a large part may be attributed to the industrial emission of the precursors SO2 and NOx.

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Assignificantimpactsofclimatechangeareincreasinglyconsideredunavoidable,adaptationhas become a policypriority. Itis generally agreedthat science is importantfor the adaptation process but specific guidance on how and to what degree science should contribute and be embedded in this process is still limited which is at odds with the high demand for science contributions to climate adaptation by international organizations, national governments and others. Here we presentandanalyzeexperiencesfromthetropicalAndesbasedonarecentscience-policyprocess on the national and supra-national government level. During this process a framework for the science contribution in climate adaptation has been developed; it consists of three stages, including(1) the framing and problemdefinition, (2)the scientific assessmentof climate, impacts, vulnerabilitiesandrisks,and(3)theevaluationofadaptationoptionsandtheirimplementation.A large amount of methods has been analyzed for stage (2), and a number of major climate adaptation projects in the region assessed for (3). Our study underlines the importance of joint problem framing among various scientific and non-scientific actors, definition of socio-environmental systems, time frames, and a more intense interaction of social and physical climate and impact sciences.Scientifically,thescarcityofenvironmental,socialandeconomic data inregions like the Andes continue to represent a limitation to adaptation, and further investments into coordinated socio-environmental monitoring, data availability and sharing are essential.