(CNN) – New York City Mayor Michael Bloomberg wrote in a surprise endorsement Thursday he was voting for President Barack Obama in the upcoming presidential election, using Superstorm Sandy as a peg to highlight the president's stance on climate change.
Citing the storm, which left much of his city underwater and powerless, Bloomberg wrote in an op-ed on his website that "while the increase in extreme weather we have experienced in New York City and around the world may or may not be the result of [climate change], the risk that it might be – given this week's devastation – should compel all elected leaders to take immediate action."
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Romney, Bloomberg wrote, is a "good and decent man" whose business experience would be a valuable asset in the White House, but his changes in positions have made the candidate a bad choice for president.
"In the past he has…taken sensible positions on immigration, illegal guns, abortion rights and health care. But he has reversed course on all of them, and is even running against the health-care model he signed into law in Massachusetts," Bloomberg, an independent who did not endorse a presidential candidate in 2008, wrote in his column.
"If the 1994 or 2003 version of Mitt Romney were running for president, I may well have voted for him because, like so many other independents, I have found the past four years to be, in a word, disappointing," the New York City mayor continued, pointing to what he regards as failures in Obama's jobs creation record and his approach to balancing the budget.
"Of course, neither candidate has specified what hard decisions he will make to get our economy back on track while also balancing the budget," Bloomberg concluded. "But in the end, what matters most isn't the shape of any particular proposal; it's the work that must be done to bring members of Congress together to achieve bipartisan solutions."
"If he listens to people on both sides of the aisle, and builds the trust of moderates, he can fulfill the hope he inspired four years ago and lead our country toward a better future for my children and yours. And that's why I will be voting for him," Bloomberg wrote.
In a statement, the president wrote he was "honored" to have secured Bloomberg's endorsement, saying "I deeply respect him for his leadership in business, philanthropy and government, and appreciate the extraordinary job he's doing right now, leading New York City through these difficult days."
"While we may not agree on every issue, Mayor Bloomberg and I agree on the most important issues of our time – that the key to a strong economy is investing in the skills and education of our people, that immigration reform is essential to an open and dynamic democracy, and that climate change is a threat to our children's future, and we owe it to them to do something about it," the president added.
In October, Bloomberg announced he was launching an "independent spending campaign" to moderate candidates in both parties during the final stretch of the election season.
The three-term mayor said he would spend eight figures on the campaign, billed as an effort to back candidates who "have shown a willingness to work in a bi-partisan fashion."
The expenditure represented Bloomberg's largest move yet to influence national races, and focused on candidates who want to crack down on illegal guns - an issue, like climate change, on which Bloomberg is highly vocal. Bloomberg has also made contributions to marriage equality referenda.
The mayor served his first two terms as a registered Republican, but ran for a third term as an independent.
CNN's Ashley Killough contributed to this report.