Companies could simply buy credits and hold them for the future as a “hedge” against the risk of price increases. The problem is, public-sector compliance credits and allowances typically expire in 2–3 years or 5 years maximum. So, that's not a very good long-term future protection.
How long do carbon offsets last?
By convention, all carbon offset credits certified under established standards are denominated using 100-year GWPs. This makes is easier to compare the effects of different GHGs and to denominate carbon offset credits in units of CO2-equivalent emission reductions.
How long is a carbon credit valid?
As carbon credits represent a certain amount of CO2 (usually one tonne), carbon credits cannot be carried over to next year. To be offset, the emissions over your next reporting year will require new credits.
