A well-known climate change skeptic has changed his mind regarding the importance of global warming, and in his new book, he is urging the spending of over $100 billion annually to help fight warming.

Bjorn Lomborg, an academic and environmental author, has held a strong opposing opinion against global warming for some time now, writing books such as "The Skeptical Environmentalist." In this book, he argues against claims regarding certain aspects of global warming, species loss, water shortages, etc. It was a controversial book when it was first published in Danish in 1998, then in English (2001).

In addition, Lomborg has campaigned against the Kyoto Protocol, which is a protocol to the United Nations Framework Convention on Climate Change that fights global warming. He has stated that humans should adapt to short-term climate rises, since they are inevitable, instead of trying to cut carbon emissions in the short-term. 

After making so many controversial statements and making his opinion against the importance of global warming known, Lomborg has now switched teams and makes this new vision clear in his upcoming book, "Smart Solutions to Climate Change," which will be published next month. 

Lomborg never denied the human role in global warming, but always argued that trying to counter climate change should be a "low priority" when it comes to government spending. Now, in his new book, Lomborg says fighting climate change is a priority and that over $100 billion should be spent annually to address the issue. 

"The point I've always been making is it's not the end of the world," said Lomborg. "That's why we should be measuring up to what everybody else says, which is we should be spending our money well."

So what made him change his mind? According to Lomborg, the Copenhagen Consensus project, which is where a group of economists are asked to consider the best way to spend $50 billion, made him reconsider global warming's importance. He noted that in 2004, global warming was put near the bottom of the list, and in 2008, new ideas for fighting global warming made it about halfway up the list. Lomborg then stated that he "decided to consider a much wider variety of policies to reduce global warming, so it wouldn't end up at the bottom." 

Lomborg now proposes a global carbon tax to raise $250 billion annually, where $100 billion will be spent on clean energy research and development, $50 billion on climate change adaptation and $1 billion on low-cost geo-engineering solutions. He wants the rest to be spent on better healthcare in poor countries and cleaner water. 

"Lomborg has acknowledged the need for public spending on man-made climate change," said Mike Childs, Friends of the Earth climate campaigner. "He is right that wind, wave and solar are the energy industries in the future and need much greater support from governments. A carbon tax to raise funds is undoubtedly part of the solution, but regulation and public spending also have their place.

"But he is still dangerously attracted to pursuing the cheapest, more risky geo-engineering solutions, is putting too much faith in future technologies and R&D, and is not giving enough support to the urgent need to reduce current emissions through rapid deployment of existing solutions and behavioral changes."

A Greenpeace spokesperson noted that while Lomborg's cross to the other side is welcomed, it's about two decade too late, and it's hard for some groups to take him seriously. According to the Guardian, some have dismissed Lomborg as "politically naive." Lomborg was an anchor in the climate change skeptic community, and his change of mind is sure to rock the boat.