Climate change could lead to hay fever misery for millions of people, a new report from University of East Anglia experts has said.

The report says the number of people suffering hay fever from ragweed pollen could double in just 35 years, and researchers believe climate change will be responsible for two thirds of this increase. Higher ragweed pollen concentrations and a longer ragweed pollen season may also increase the severity of symptoms.

Lead researcher Dr Iain Lake, from UEA's School of Environmental Sciences, said: 'Pollen allergy is a major public health problem globally...This is the first study to quantify what the consequences of climate change on pollen allergy may be.'

The team investigated the potential impacts of climate change on ragweed plant distribution, plant productivity, pollen production and dispersal, and the resulting allergy impacts across Europe. They found the number of people affected by ragweed pollen is likely to increase in Europe from 33 to 77 million people by as soon as 2050. Dr Lake said: 'Our research shows that ragweed pollen allergy will become a common health problem across Europe, expanding into areas where it is currently uncommon. The problem is likely to increase in countries with an existing ragweed problem, such as in Hungary and the Balkans. But the greatest proportional increases will happen in countries including Germany, Poland and France.'

While France and north west Italy are likely to see airborne ragweed pollen from mid-July to mid-August, the report's projections suggest ragweed pollen will persist from mid-September to mid-October across most of Europe. The UEA has worked with several European institutes on the report called Climate Change And Future Pollen Allergy In Europe.