Weather and climate are separate if related concepts that are innocently confused by our own memories of recent weather events and deliberately confused by many involved in the politicised arguments about climate change. Weather describes the atmospheric conditions today and patterns that last up to a decade. Climate is the very long term average of those patterns within recorded experience.
I am in Buenos Aeries having just left hot and dry Chile on my way to the weather engine of the globe, the Antarctic.
Australia is sandwiched between the two big weather engines of the Earth, the globe circling ice-cold currents of the Great Southern Ocean and the tropical cloud band forming hot seas to its northwest.
This year the spring and early summer in Chile is warm and dry in contrast to immediate past vintages. The responsible agent for Chile’s warmth is La Nina, the Pacific Ocean wind and sea surface temperature phenomenon that is also ensuring Adelaide is wet during the second cricket test and that our vineyards in South Australia will continue to receive abnormal rainfall until the last grape is picked in April and beyond.
For the past 6 vintages (2005 to 2010) our vineyards have been in the grips of La Nina’s alter ego El Nino inflicting drought, heat waves and early vintages. We have forgotten the cool and wet sequence of vintages from 1992 to 1997 and the vineyard disease management problems, flavour ripeness challenges and late harvests of that sequence of vintages.
I suspect we are about to be reminded and not just for vintage 2011.
BJC, 6/12/2010
