Last week, we told you that African nations had banded together and announced that they would probably need $67 billion a year to help mitigate the effects of climate change. Well, if you thought that was quite a chunk of change, you ain’t seen nothing yet, as a new report states that developing nations need at least $500 billion a year to help combat climate change. Five. Hundred. Billion. Dollars. Which is a lot of money.

The New York Times states that the figure in United Nations report is way higher than anyone expected it to be, and will be required per year for at least a decade. And, well, who’s actually paying this half-trillion?

That astronomical estimate, far higher than any previously suggested by the United Nations, comes at a time when developed and developing nations are still deeply divided over who bears the responsibility for shouldering the expense of deploying cleaner energy resources, much less what the actual amount might be.

As Treehugger.com reports (who also gets credit for alerting us to the story), this is not a good number to have thrown in the world’s lap right before the Copenhagen Conference, but it is something that must be dealt with.

With the Copenhagen global climate talks drawing near, this is bad news–$500 billion dollars is around 1% of the entire global economic output. But it may be absolutely necessary–the number comes from the estimated cost of supplying developing nations with solar, wind, or other renewable energy while they create needed infrastructure.

So, how will this $500 billion magically appear? Carbon taxes? Straight up aid from developed nations to developing ones? Seeing as the original thought was that it the number would be somewhere around $100 billion, and even THEN we couldn’t figure out how to pay for it, this certainly is going to cause some heated debate in the coming months. But, if an agreement is going to be reached in Copenhagen that caps carbon output from developing nations, it seems natural that those nations would demand monetary compensation in return. There’s even a possibility that on top of the $500 billion to mitigate climate change, developing nations may demand more money to compensate for having to 1) spend more to go green and 2) losing money by not being able to use established technologies. All in all, with this report, I just got a lot more worried about how well things will go in Copenhagen.

photo credit: oxfam international’s flickr photostream/Creative Commons