The study above does NOT say that every record breaking weather condition is caused by man. They are looking at the percentage of such events in which manmade conditions play a part. Their finding is that the percentage of man vs nature is rising. This is a simple way of looking at the issue by asking "Are there other conditions non man made which are influencing weather? And how does that compare to other explanations including man for extreme change in weather?" Here is a good way to look at it from some charts with real data look at it as a question and not a conclusion if you like, then try to find an explanation that works better.   https://www.bloomberg.com/graphics/2015-whats-warming-the-world/