Global warming may cripple Californian wine industry

California's formidable wine industry has just had its parade thoroughly rained upon by a sector of the US's scientific fraternity, who have predicted that the future of this gargantuan producer might be about as secure as dinosaurs facing down a meteor.

Within the next 100 years, global climate change is expected to bring to its knees an industry which is valued at $3,2 billion in California's powerful $30 billion agricultural sector (grapes come in second behind dairy products as the biggest commodity in the state).

The Carnegie Institute of Washington's Department of Global Ecology, based at Stanford University, in collaboration with the National Academy of Sciences, produced a report which took an unblinkered look at the fate of California's irrigation-dependent agriculture sector in the face of global warming.

Increasing temperatures, the melting of the Sierra Nevada snowpack and increasing heat waves emerged as the most formidable possible threats facing the region in the coming century.

Four different computer climate modelling scenarios, based on those used by the United Nations' Intergovernmental Panel on Climate Change (IPCC), showed that a general increase in average annual temperatures can be expected.

Across the state, the southwest coast region will experience 'lesser warming' but greater increases will occur in the north and northeast of the state.

Summertime temperature increases (expected to be greater than winter increases) and a decrease in winter snowfall could combine to seriously reduce the accumulation of snow on the Sierra Nevada mountains. Melting snow is critical to feeding the rivers and reservoirs upon which California's agriculture is dependent. Increased temperature also means an increase in water evaporation.

By the latter part of the century the Sacramento River is expected to experience extreme droughts which will 'exceed in length, frequency and severity anything experienced during the 20th century'.

Another critical factor will be an increase in heat wave conditions, defined as when the mercury climbs above 32°C for three days or longer. Besides the obvious impact on vineyard health, these climatic extremes are expected to significantly influence heat-related deaths.

Besides increased water stress, higher temperatures are expected to severely undermine the quality of grape production and possibly move forward the seasonality of ripening.

California's wine industry has become something of a Goliath in the international arena. Last year its wine exports were shipped to 133 countries, amounted to $643 million and achieved new records in both volume and value.

It's wines successfully knocked Italy from its spot as third biggest player in the competitive UK market, placing Californian wine's behind France and Australia as the first and second largest holders of market share there.

Su Birch, CEO of Wines of South Africa, said California's wines are currently going head to head with South African wines in SA's most significant UK slot - the £5 to £8 sector. In the USA market, California's wines also compete with SA's exports which are targeting the $10 to $20 'fine wine' sector.

Hypothetically, if California's wines were to suddenly exit these markets, they would leave a huge space for other competitors to fill.

This doesn't necessarily spell good news for South Africa's wine industry (or any other country's, for that matter) as each region will have to struggle with its own changing conditions as global warming predictions unfold over the next century.

by Leonie Joubert [ wine.co.za ]