We have purchased our REC's for our building's electricity use but have been unable to find anyone that offers carbon offsets for our natural gas use because it's so low (less than 1MMBtu a year). How do we go about fulfilling the EAc4 if we're not able to purchase these? (We are still covering 99.99% of the building's total energy use with the REC purchase but don't want to get tripped up in the review process and lose points for not having the gas usage covered.) thoughts?