The cold war map of Europe may have melted but it seems an iron curtain of climate change is now dividing the continent, writes Steve Farrar.
Scientists have found that while springtime is beginning earlier in western and central Europe, in the east it is starting later.
The division is the result of the complex impact of climate change on the air temperature over the continent: the west is dominated by warmer Atlantic air masses, while the east is being influenced by cooler air from Siberia.
A team of experts led by Rein Ahas, a geographer at the University of Tartu, Estonia, used the phenological database created as part of the European framework programme-funded Positive project to plot the gradual climate shifts.
The database is made up of large amounts of observational data on European nations from Spain to the post-Soviet states.
It details when trees such as hazel, birch, apple and lilac go through their annual phases of growth, such as budding and flowering, changes triggered by rising air temperature.
From this information, the scientists were able to chart the rate and spatial pattern in spring phenology - the points at which plants respond to seasonal warming - between 1951 and 1998.
They found that spring phases had advanced four weeks in western and central Europe and had, over the same period, been delayed by up to two weeks in eastern Europe.
Among the plants found to be particularly affected by the shifting seasons were hazel and coltsfoot in western Europe and the Baltic Sea regions, which started to respond to spring between 0.3 and 0.4 of a day earlier each year on average.
The findings are published in the International Journal of Climatology .