GAO adds Climate Change as Fiscal High Risk for U.S.

Yes, CO2 (carbon dioxide) sequestration could help reduce or mitigate the human forcing of climate change. Unfortunately the path and practical aspects are neither simple, nor easy.  A brief overview: 

We are warming the atmosphere and indirectly the ocean because CO2 has incredible insulating properties and acts like a sheet of glass in a greenhouse. We are now at 393 ppm (parts per million) 40% higher than the "natural range" of 180-280 for the last ten million years. The amount increases about 3 points a year due to burning fossil fuels.

Sometimes referred to as CCS for Carbon Capture and Storage, there are actually two different applications 

One is to capture it as we produce our power, such as removing CO2 from the smokestack of a an oil or coal fired power plant. So far we cannot do it economically.

Another approach is to take it out of the atmosphere. Since it is only one molecule in about 2500 that is a challenge. We need to do it without using  much energy since that would make the problem worse. There are efforts to come up with so called "artificial trees."

Assuming either of the above can be done cost effectively there is the non-trivial problem of where to store the carbon or the CO2. There are experiments to put it underground.

Then there are experiments to make phytoplankton or other forms of algae grow faster in the ocean as a natural way to sequester CO2. Because there is no external energy required and because of the ocean's vastness, this has considerable potential in my opinion.

All should be explored. I can't put a dollar figure on how much to invest in these.

Even if we do figure out CCS and reduce the level of GHG and begin to reverse the warming, the sea will still rise for centuries.