* Siberia registers its warmest recorded spring sparking new fears for rapid climate change

Some parts of Siberia were warmer than usual by 6C, with a host of anecdotal examples of normal meteorological rules being turned on their head. For a few days in late April, for example, the city of Irkutsk boasted higher temperatures than Madrid. 

The ice on vast Lake Baikal was too thin or non-existent even in February and March, forcing the cancellation of a number of events. 

In the past, it was safe to drive cars across the frozen lake, the deepest in the world.