DEFORESTATION is responsible for today鈥檚 drier Mediterranean climate, say
Oreste Reale and Paul Dermeyer of the Center for Ocean Land Atmosphere Studies
at Calverton in Maryland.
They worked out how much and what kind of plant cover there was 2000 years
ago, based on fossil pollen and historical records from ancient Roman times. The
more extensive vegetation at this time would have trapped more of the Sun鈥檚
energy and released more moisture into the atmosphere. A computer simulation
shows that this would have affected atmospheric circulation over the Med and
made a big difference to the climate, with north-western Africa in particular
enjoying far more rainfall 2000 years ago (Global and Planetary Change,
vol 25, p 185).
But as the forests were destroyed, the climate changed and less rain fell.
鈥淚t is extremely important we protect sub-arid environments to stop this
situation getting worse,鈥� says Reale.
Advertisement