**1.1 Global climate change**

Climate changes are the mammoth challenges that human race will face in coming decades as described by Intergovernmental Panel on Climate Change. The increase in release of greenhouse gases, particularly CO2 is considered as the main cause of global warming. The concentration of CO2 has increased from 280 ppm to 400 ppm

subsequently of 0.5–1°C rise in an average temperature. It is expected that mean global temperature will rise by 0.2–0.3°C per decade hence rise of 1.2 to 5.8°C by the end of the twenty-first century. The increase in mean temperature in key viticulture regions was 1.6–1.8°C in Europe and 1.2–1.4°C across the globe during the growing seasons from 1950 to 2000 [1–4]. Similarly, a decrease in precipitation has been recorded in over southern Europe [5]. In addition to rising temperature, corresponding heat waves are becoming more common and frequent. Climate change is no doubt an inevitable challenge that must be dealt with serious policies in the upcoming decades. It is a major challenge that viticulture industry has to face in coming decades.

#### **1.2 Climate a key determinant for viticulture**

Climate is a limiting factor determining phenology, vegetative growth, physiological development, fruit production and consequently wine quality [6–8]. Geographical distribution of vineyards is determined by climatic factors. Weather parameters: temperatures, solar radiation, precipitation, and the inter-annual seasonal variability leads to annual changes in vine productivity [9–11]. Extreme weather events: hailstorms, excessive rainfall, late frost spells have been recognized as factors having detrimental impacts on grapevine productivity and quality [12].

#### **1.3 Climate change impacts on viticulture**

It is evident that climate change will have a negative impact on viticulture industry. Higher temperature during the active growing season will strongly affect grapevines because it is a major driver of development stages of grapevine [13]. Extreme heat stress during ripening period will abruptly reduce grapevine metabolism. It may result in higher sugar levels and lower acidity with potential increase in chances of wine spoilage [14] thereby lower production and quality. Furthermore, extreme heat and water stress, under future climates, may threaten final yields and productivity [15].
