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Temperature (Trends -- Regional: Europe, Mediterranean) -- Summary
Temperature histories of the regions surrounding the Mediterranean Sea have many things in common with those of other parts of Europe.  Consider, for example, the study of Hasanean (2001), who analyzed data obtained from the Eastern Mediterranean cities of Malta, Athens, Tripoli, Alexandria, Amman, Beirut, Jerusalem and Lataki, which cities possess temperature records stretching from 1853 (Malta, the longest) and 1952 (Latakia, the shortest) to 1991 (the last year for which data were analyzed in this study).  Of the temperature histories of these eight cities, four exhibited overall warming trends, while four exhibited cooling trends.  In addition, Hasanean notes the presence of an "important warming around 1910," which began nearly simultaneously at all of the longer-record stations.  A second warming was noted in the 1970s; but it was "not uniform, continuous or of the same order" as the warming that began in 1910, nor was it evident at all of the stations.  Hence, as with most of the rest of Europe, it appears that the most significant warming of the 20th century in these Eastern Mediterranean locations occurred well before the period of most significant anthropogenic CO2 emissions, i.e., the latter half of the 20th century.

In an even more comprehensive study, Xoplaki et al. (2001) analyzed over 1100 proxy climate records from various places across the southern Balkans and the Eastern Mediterranean area for the periods 1675-1715 and 1780-1830, comparing them with observational records for the 1961-1990 time period.  Concentrating more on the variability of climate than its historical trend, they found that extreme temperature and precipitation events in the two early time periods (when temperatures were colder) were much more apparent than they were during the more recent (and warmer) time period, which observation contradicts the results of climate model-derived simulations that suggest earth's climate is more variable in warmer, as compared to colder, conditions.

In another study whose results fly in the face of climate model-derived wisdom, Kadioglu et al. (2001) analyzed heating degree-days (HDDs) and cooling degree-days (CDDs) at 74 stations located throughout Turkey over the period 1930-1996.  They found that much of the country displayed no significant trend in the annual number of HDDs or CDDs over the period of record.  However, where significant trends did exist, they were found to be inconsistent with what is predicted by high-resolution global climate models.  For example, decreasing trends in the number of CDDs were found in all seasons of the year in the eastern part of Turkey (signifying a decreasing trend in mean daily temperature in all seasons); while increases in HDDs were reported for the fall in the region near the Black Sea (also signifying a decreasing trend in mean daily temperature in the fall).  In other words, over the past 70 years, some parts of Turkey have gotten colder, not warmer.  Hence, it is not surprising that Kadioglu et al. say the results of their study "do not provide empirical support for the [climate] model simulations."

Out in the middle of the Mediterranean, at a site on the northwest coast of Sicily, Silenzi et al. (2004) "present new data on sea climate trend fluctuations that could be interpreted as Sea Surface Temperature (SST) variations, recorded on Vermetid (Dendropoma petraeum) reefs, by means of [oxygen] isotopic analysis."  Following the Little Ice Age, their data reveal what they call "the warming trend that characterized the last century," which "ended around the years 1930-1940 AD, and was followed by a relatively cold period between the years 1940 and 1995."

Rounding out this sampling of studies from Mediterranean and nearby regions, Correia and Safanda (1999) reviewed a set of twenty temperature logs derived from boreholes located at fourteen different sites in mainland Portugal in an attempt to reconstruct a five-century surface air temperature history for that part of the world.  Seven of the borehole temperature logs turned out to be too "noisy" to use; while six displayed evidence of groundwater perturbations and were also not usable.  Of the remaining seven logs, all depicted little temperature change over the first three centuries of record.  Thereafter, however, four of them exhibited warming trends that began about 1800 and peaked around 1940, one showed a warming that peaked in the mid-1800s, another was constant across the entire five centuries, and one actually revealed cooling over the last century.

Among all of the many observations reported in the papers discussed above, there is next to nothing to suggest a significant net warming of the Mediterranean region over the last half of the 20th century, when mankind's CO2 emissions were far greater than they were over all prior half-century periods; and, therefore, there is good reason to believe that something other than the rising CO2 content of the atmosphere was responsible for the truly significant warming that occurred over the first half of the 20th century, as well as the latter half of the 19th century, when atmospheric CO2 concentrations rose ever so slightly.

References
Correia, A. and Safanda, J.  1999.  Preliminary ground surface temperature history in mainland Portugal reconstructed from borehole temperature logs.  Tectonophysics 306: 269-275.

Hasanean, H.M.  2001.  Fluctuations of surface air temperature in the Eastern Mediterranean.  Theoretical and Applied Climatology 68: 75-87.

Kadioglu, M., Sen, Z. and Gültekin, L.  2001.  Variations and trends in Turkish seasonal heating and cooling degree-days.  Climatic Change 49: 209-223.

Silenzi, S., Antonioli, F. and Chemello, R.  2004.  A new marker for sea surface temperature trend during the last centuries in temperate areas: Vermetid reef.  Global and Planetary Change 40: 105-114.

Xoplaki, E., Maheras, P. and Luterbacher, J.  2001.  Variability of climate in meridional Balkans during the periods 1675-1715 and 1780-1830 and its impact on human life.  Climatic Change 48: 581-615.