What is the fine-grained topic of the following text: Severe spring frosts followed by spikes of extreme hot weather across Europe mean Italy, France and Spain — the world’s biggest wine-producing nations — are expected to register declines of wine output by 23 per cent, 19 per cent and 15 per cent respectively on last year, according to the International Organisation of Vine and Wine (OIV). Only return the topic.
Projected decline in wine production in Italy, France, and Spain due to extreme weather conditions