Complex sentence: The Red List of 2012 was released 19 July 2012 at Rio +20 Earth Summit; nearly 2,000 species were added, with 4 species to the extinct list, 2 to the rediscovered list.
Split into simpler sentences: The Red List of 2012 was released 19 July 2012 at Rio +20 Earth Summit. Nearly 2000 species were added, 4 species to the extinct list, 2 to the rediscovered list.