40% over 5 years old, new analysis says

Why it matters:

Technologies and models for the measurement and verification of carbon offsetting have undergone significant development in recent years, raising hopes that efficient and trustworthy carbon credits markets can be established.

However, thousands of credits generated under older, arguably less-rigorous schemes remain ‘in circulation.’ Not only is the positive environmental impact of many of these credits questionable — due to the problem of additionality — but trading them could have a bearish effect on carbon prices, hobbling the nascent market. One study estimates that as much as 700 million carbon equivalent tons’ worth of “old” credits — up to eight times the current demand — with “little to no additionality” could flood the market and be purchased, with negligible climate impact.

Agriculture produces just 1% of carbon credits, data suggests – read more here

At COP26 last November, countries agreed to a 2013 cut-off date for the validity of certain credits generated under criteria set by the 1992 Kyoto Protocol, in order to remove thousands of potentially problematic assets from the market.