In order to limit climate change to increasing global temperatures by only two degrees Celsius (3.6 degrees Fahrenheit), a goal set by the United Nations, the United States will need to pay up an additional $800 billion a year from now until 2050, according to a new study.

Published in the journal Climate Change Economics, the study notes that the United States is fully capable of raising that much capital, but it means shifting away from investing in fossil fuels - currently a $500 billion annual investment - towards clean energy.

"We know that if we want to avoid the worst impacts of climate change, we need to drastically transform our energy system," lead researcher David McCollum, of the International Institute for Applied Systems Analysis (IIASA), said in a statement. "This is a comprehensive analysis to show how much investment capital is needed to successfully make that transition."

Investments in clean energy right now are around $200-$250 billion a year, with a projected growth to $400 billion. But based on global energy-economic models, as well as future energy investment scenarios, researchers determined that to reach the two degrees Celsius goal, that number will have to jump to a whopping $1,200 billion a year.

"Many countries say that they're on board with the a target of two degrees Celsius global mean temperature stabilization by 2100; some have even made commitments to reduce their greenhouse gas emissions. But until now, it hasn't been very clear how to get to that point, at least from an investment point of view," McCollum explained.

"It's high time we think about how much capital is needed for new power plants, biofuel refineries, efficient vehicles, and other technologies - and where those dollars need to flow - so that we get the emissions reductions we want."

There's no doubt it's a slippery slope. The United States needs to start thinking more about a future in clean energy rather than fossil fuels if it hopes to keep its promise in combating climate change. Otherwise, as another recent bipartisan report entitled "Risky Business" states, the US economy won't be able to afford global warming.

President Barack Obama has already started taking steps in the right direction with his plan to cut carbon emissions produced from power plants by 30 percent before 2030.