Fossil fuel companies must be held responsible for the extreme heatwave gripping Europe. Campaigners from 350.org say they should pay permanent windfall taxes to help cover the mounting health costs. A new study by World Weather Attribution found that climate change is “unequivocally” the driving force behind Europe’s record-breaking heatwave. The study found that: Heatwave temperatures would have been “virtually impossible” to occur at this time just 50 years ago. Overnight temperatures are about 100x more likely today. Almost half of more than 800 cities across 30 European countries have broken, or are likely to break, heat stress levels. UN climate…