Dust from distant lands

It seems astonishing that the Amazon rainforest is fertilised by Saharan dust blown across the Atlantic. The large sand grains in dust storms fall quickly to the ground, but smaller particles can travel thousands of kilometres. Saharan dust can cause air pollution in the eastern Mediterranean to reach 10 times European limits. Italy, Spain and Portugal are also frequently affected.

The southerly winds that gave most of the UK its warmest December on record also bought Saharan dust. From London to South Wales, it caused air pollution to reach four on the 10-point UK pollution scale on the 17th and eight on the 27th . Smaller quantities were measured in Leicester and over most of England.