El Nino, NAO key climate drivers in 2015

Guy Carpenter & Company reported that 2015 marked one of the strongest El Niño periods on record, while a positive phase of the North Atlantic Oscillation (NAO) was evident both at the beginning and close of the year.

According to Guy Carpenter’s Global Catastrophe Review – 2015, although these prominent climate drivers were associated with an exceptional tropical season in the Pacific and severe windstorms and flooding in Europe, 2015 was a quiet year in terms of global insured losses, which totalled around USD30.5 billion. Insured losses were below the 10-year and five-year moving averages of around USD49.7 billion and USD62.6 billion, respectively. Last year also marked the lowest total insured catastrophe losses since 2009 and well below the USD126 billion seen in 2011.

Characterised by warm waters in the tropical east Pacific, the strong El Niño seen in 2015 was associated with record-setting tropical cyclone activity in the North Pacific basin, but relatively quiet activity in the North Atlantic. The positive NAO phase, such as observed in the 2014/2015 winter season, is often associated with increased storm transits and greater storm severity.