A new research has shown that the pollen season became worse and longer because of human-made climate change. The study shows that the pollen season is 20 days earlier and 10 days longer compared to 30 years ago. There has also been 20.9% more pollen in recent years. Several factors such as changes in temperature, rainfall, frost days, and even carbon dioxide amount were looked at. The researchers found that the rise in average temperature was the biggest factor. The study’s lead author, William Anderegg, said that the study connects climate change to pollen, one of the main causes of asthma, allergies, and other respiratory health problems.