The water holding capacity of the atmosphere is governed by the Clausius-Clapeyron equation, which states that the saturation vapour pressure grows with temperature (at the rate of 6–7% per 1◦C increase in temperature). In other words, warmer air can contain more water vapour. A statistically PD-166866 in vivo significant increase in the frequency of intense precipitation has already been observed at many (but not all) meteorological stations, both

in Europe (Zolina 2012) and in Poland. Moreover, the structure of the precipitation process has changed: short, isolated precipitation events are now giving way to longer precipitation events (Zolina 2012). The mean annual and seasonal precipitation

TSA HDAC has been observed to increase at most weather stations in Poland and to decrease at some others, but many of these changes are not statistically significant. There has been a pronounced, but not ubiquitous, increasing tendency in the intensity of rainfall. However, the inter-annual variability of precipitation is very strong. Changes in the seasonality of precipitation involve a decrease in the ratio of warm-season precipitation to cold-season precipitation (Pińskwar 2009) and also in the proportion of liquid to solid precipitation in winter. The frequency Benzatropine of synoptic weather patterns that are likely to lead to intense precipitation and floods has been on the rise (Niedźwiedź

et al. 2014). There has been an increasing number of local floods in urban areas (flash floods), including large towns (or parts thereof), caused by intense rainfall, when the capacity of the urban sewage systems is too small, or when the urban outflow is obstructed by a flood wave in the river. Flood damage potential in Poland has increased considerably, in the wake of urbanisation and the ubiquitous increase of wealth. Increasing flood exposure results from human encroachment onto floodplains and the economic development of flood-prone areas. The assets at risk from flooding are high, and growing dynamically. Sensitivity to floods has increased since the change of the political and economic system in the early 1990s, accompanying the constantly (for over 20 years now, including the difficult year 2009) growing national GDP. Trends established for Polish tide gauge stations show that the annual mean sea level has been increasing over the last century. Observations of sea level changes in Świnoujście belong to the longest series of records, globally (Pruszak & Zawadzka 2008). More recently the sea level rise has accelerated, up to 0.3 cm yr− 1.