Future predicted climate changes

Current climate modelling work, using a range of predictions with regard to CO₂ emissions, indicates which are the largest contributors to total increases in temperatures, projects that the globally averaged surface temperature will increase 1.3–4.8 °C/2.34–8.65 ºF by the 2081–2100 period relative to what was seen globally during the 1986–2005 period (see figure). This level of change is between two and ten times greater than that which was observed during the 20th century. The projected warming will continue to exhibit interannual-to-decadal variability and will not be regionally uniform, with variation in the rate of warming and whether the warming comes from greater increases in daytime or night-time temperatures. Research suggests that growing-season temperatures will increase by 2.0 ºC/3.6 ºF by 2050, with increased seasonal temperature variability. However, the warming rates in wine regions are likely to vary: locations in the northern hemisphere are expected to warm more than those in the southern hemisphere. In addition, regions at higher latitudes or inland are expected to warm more than those in coastal zones. Both observations and models also suggest that in Australia and California this projected warming is likely to lead to a decrease in rainfall in most viticultural locations, leading to greater water stress and reductions in water resources in the future.