Multiproxy reconstructions of monthly and seasonal surface temperature fields for Europe back to 1500 show that the late 20th- and early 21st-century European climate is very likely (>95% confidence level) warmer than that of any time during the past 500 years. This agrees with findings for the entire Northern Hemisphere. European winter average temperatures during the period 1500 to 1900 were reduced by approximately 0.5 degrees C (0.25 degrees C for annual mean temperatures) compared to the 20th century. Summer temperatures did not experience systematic century-scale cooling relative to present conditions. The coldest European winter was 1708/1709; 2003 was by far the hottest summer.

In the Mediterranean Basin, recent accelerated changes in the environment (climate, land use, pollution, biodiversity loss) have caused loss of life and damages to infrastructure and ecosystems. The future presents unprecedented risks for human well-being, socioeconomic development, ecosystems and biodiversity. Policies for sustainable development need to aim for the mitigation of these risks but lack adequate information about the rates of environmental change and the combined risk they present to human society. For five interconnected impact domains (water, ecosystems, food, health and security), trends and scenarios point to significant risks during coming decades. More observations and better impact models exist for the Northern Mediterranean shores than for the South. This important bias is exacerbated by the large difference in financial resources available for adaptation and the development of resilience between north and south. A dedicated effort to synthesize existing scientific knowledge from all relevant disciplines is now underway to provide better understanding of the risks posed. In the Mediterranean Basin, human society and the natural environment have co-evolved over several millennia with significant climatic variations, laying the ground for diverse and culturally rich communities. The region lies in a transition zone between mid-latitude and subtropical circulation regimes. It is characterized by a complex morphology of mountain chains and strong land-sea contrasts, dense and growing human population and various environmental pressures. Observed rates of climate change in the Mediterranean Basin exceed global trends for most variables. Annual mean temperatures are now 1.4 °C above late nineteenth century levels (Figure 1), notably during the summer months. Heat waves occur more frequently, and the frequency and intensity of droughts have increased since 1950. 1,2,3 For each of the most recent decades, the surface of the Mediterranean Sea has warmed by around 0.4 °C. 4 During the period 1945-2000, sea-level has risen at a rate of 0.7±0.2 mm yr-1 , 5 accelerating to 1.1 mm yr-1 for the period 1970-2006. 6 During the last two decades, sea-level has been estimated to rise by about 3 cm decade-1 , 7 in part due to

This review of late-Holocene palaeoclimatology represents the results from a PAGES/CLIVAR Intersection Panel meeting that took place in June 2006. The review is in three parts: the principal high-resolution proxy disciplines (trees, corals, ice cores and documentary evidence), emphasizing current issues in their use for climate reconstruction; the various approaches that have been adopted to combine multiple climate proxy records to provide estimates of past annual-to-decadal timescale Northern Hemisphere surface temperatures and other climate variables, such as large-scale circulation indices; and the forcing histories used in climate model simulations of the past millennium. We discuss the need to develop a framework through which current and new approaches to interpreting these proxy data may be rigorously assessed using pseudo-proxies derived from climate model runs, where the `answer' is known. The article concludes with a list of recommendations. First, more raw proxy data are required from the diverse disciplines and from more locations, as well as replication, for all proxy sources, of the basic raw measurements to improve absolute dating, and to better distinguish the proxy climate signal from noise. Second, more effort is required to improve the understanding of what individual proxies respond to, supported by more site measurements and process studies. These activities should also be mindful of the correlation structure of instrumental data, indicating which adjacent proxy records ought to be in agreement and which not. Third, large-scale climate reconstructions should be attempted using a wide variety of techniques, emphasizing those for which quantified errors can be estimated at specified timescales. Fourth, a greater use of climate model simulations is needed to guide the choice of reconstruction techniques (the pseudo-proxy concept) and possibly help determine where, given limited resources, future sampling should be concentrated.

Spatially and temporally high-resolution estimates of past natural climate variability are important to assess recent significant climate trends. The mid-latitude atmospheric circulation is the dominant factor for regional changes in temperature, rainfall, and other climatic variables. Here we present reconstructions of gridded monthly sea level pressure (SLP) fields back to 1659 and seasonal reconstructions from 1500-1658 for the eastern North Atlantic-European region (30°W to 40°E; 30°N to 70°N). These were developed using principal component regression analysis based on the combination of early instrumental station series (pressure, temperature and precipitation) and documentary proxy data from Eurasian sites. The relationships were derived over the 1901-1960 calibration period and verified over 1961-1990. Under the assumption of stationarity in the statistical relationships, a transfer function derived over the 1901-1990 period was used to reconstruct the 500-year largescale SLP fields. Systematic quality testing indicated reliable winter reconstructions throughout the entire period. Lower skill was obtained for the other seasons, although meaningful monthly reconstructions were available from around 1700 onwards, when station pressure series became available. The quality and the reconstructed SLP fields for two exceptionally cold years (1573, 1740) are discussed and climatologically interpreted. An EOF analysis of the 1500-1999 winter SLP revealed, firstly, a zonal flow pattern with pronounced decadal to centenial time scale variations, secondly, a monopole pattern over northwest Europe and thirdly, a pattern modulating the meridional flow component over Europe. These 500year SLP reconstructions should be useful for modelling studies, particulary for analyses of low-frequency atmospheric variability and for circulation dynamics.

The influence of the large-scale atmospheric circulation at several tropospheric levels on wet season precipitation over 292 sites across the Mediterranean area is assessed. A statistical downscaling model is designed with an objective methodology based on empirical orthogonal functions and canonical correlation analysis (CCA) and tested by means of crossvalidation. In all 30% of the total Mediterranean October to March precipitation variability can be accounted for by the combination of four large-scale geopotential height fields and sea level pressure. The Mediterranean sea surface temperatures seem to be less relevant to explain precipitation variability at interannual time scale. It is shown that interdecadal changes in the first CCA mode are related to variations in the North Atlantic Oscillation index and responsible for comparable time scale variations of the Mediterranean precipitation throughout the twentieth century. The analysis reveals that since the mid-nineteenth century precipitation steadily increased with a maximum in the 1960s and decreased since then. The second half of the twentieth century shows a general downward trend of 2.2 mmAEmonth-1 AEdecade-1 .

We evaluate variability, trends, uncertainties, and change of extremes of reconstructed and observed European spring and autumn temperature back to 1500. Spring and autumn temperature experienced systematic century‐scale cooling compared to present conditions. The coldest springs appeared during the Maunder Minimum (ΔT = −1 K wrt 1901–2000). The amplitude of spring temperature variations at decadal and multidecadal scales doubles that of autumn and is most expressed in northeastern Europe. The decade 1995–2004 was very likely the warmest of the last half millennium. Anomalously warm springs and autumns have generally become more extreme in recent decades. However, the recent changes are statistically not significant with respect to the pre‐industrial period.

[1] We analyze century-long daily temperature and precipitation records for stations in Europe west of 60°E. A set of climatic indices derived from the daily series, mainly focusing on extremes, is defined. Linear trends in these indices are assessed over the period 1901-2000. Average trends, for 75 stations mostly representing Europe west of 20°E, show a warming for all temperature indices. Winter has, on average, warmed more ($1.0°C/100 yr) than summer ($0.8°C), both for daily maximum (TX) and minimum (TN) temperatures. Overall, the warming of TX in winter was stronger in the warm tail than in the cold tail (1.6 and 1.5°C for 98th and 95th, but $1.0°C for 2nd, 5th and 10th percentiles). There are, however, large regional differences in temperature trend patterns. For summer, there is a tendency for stronger warming, both for TX and TN, in the warm than in the cold tail only in parts of central Europe. Winter precipitation totals, averaged over 121 European stations north of 40°N, have increased significantly by $12% per 100 years. Trends in 90th, 95th and 98th percentiles of daily winter precipitation have been similar. No overall long-term trend occurred in summer precipitation totals, but there is an overall weak (statistically insignificant and regionally dependent) tendency for summer precipitation to have become slightly more intense but less common. Data inhomogeneities and relative sparseness of station density in many parts of Europe preclude more robust conclusions. It is of importance that new methods are developed for homogenizing daily data.

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