"The trip to Canada was an eye-opener, people realised there was ice hockey in Kenya and we were able to recruit more locals into the sport," said Mburu.

It would be a real eye-opener if United go to Emirates Stadium and get something, but I can't see it.

“This study should be an eye-opener for political leaders hanging on to fossil fuels that heat the planet and destroy lives”, said Dr Friederike Otto, co-founder and lead of WWA.

“We've lived in Hull for 30 years, if not more. We've never seen something like this happening in the city. So, it was really an eye-opener – and scary.”

"The Ryder Cup was an eye-opener for me," he said.