4:01PM EDT November 1. 2012 - He may have discouraged a post-storm presidential visit this week, but New York Mayor Michael Bloomberg endorsed President Obama for re-election Thursday.

His big issue: climate change.

"We need leadership from the White House - and over the past four years, President Barack Obama has taken major steps to reduce our carbon consumption, including setting higher fuel-efficiency standards for cars and trucks," Bloomberg wrote in a column for the Bloomberg News website.

Bloomberg added: "His administration also has adopted tighter controls on mercury emissions, which will help to close the dirtiest coal power plants (an effort I have supported through my philanthropy), which are estimated to kill 13,000 Americans a year."

Obama said he was "honored" by the endorsement, adding: "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."

As for Republican opponent Mitt Romney, Bloomberg wrote that while Romney backed a "cap and trade" plan to reduce carbon emissions while he was governor of Massachusetts, he backed away from it during this year's presidential campaign.

"This issue is too important," Bloomberg said. "We need determined leadership at the national level to move the nation and the world forward."

The New York City mayor attributed the ferocity of this week's Hurricane Sandy to changes in the climate.

White House staff and Bloomberg discussed the possibility of an Obama visit to New York to inspect storm damage, but that did not happen; the president went to neighboring New Jersey.

Bloomberg, a Republican-turned-independent, did have some criticism for Democrat Obama in his column.

While running as a "consensus builder" four years ago, the president has "devoted little time and effort to developing and sustaining a coalition of centrists, which doomed hope for any real progress on illegal guns, immigration, tax reform, job creation and deficit reduction," Bloomberg wrote. "And rather than uniting the country around a message of shared sacrifice, he engaged in partisan attacks and has embraced a divisive populist agenda focused more on redistributing income than creating it."

Obama has also had "important victories," Bloomberg wrote:

"His Race to the Top education program - much of which was opposed by the teachers' unions, a traditional Democratic Party constituency - has helped drive badly needed reform across the country, giving local districts leverage to strengthen accountability in the classroom and expand charter schools. His health-care law - for all its flaws - will provide insurance coverage to people who need it most and save lives."

Here is Obama's full statement:

"I'm honored to have Mayor Bloomberg's endorsement. 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. Just as importantly, we agree that whether we are Democrats, Republicans, or independents, there is only one way to solve these challenges and move forward as a nation - together.

"I look forward to thanking him in person - but for now, he has my continued commitment that this country will stand by New York in its time of need. And New Yorkers have my word that we will recover, we will rebuild, and we will come back stronger."