London - Firms in Britain's FTSE 100 index offset just 0.1% of their greenhouse gas emissions, voluntarily, a volume which is "pitifully low", a report said on Monday.
"If the FTSE 100 are to make meaningful steps towards reducing their collective environmental impact, then offsetting, as well as ambitious emission reduction strategies, must play a more substantial role," said the report by UK offsetting firm Carbon Retirement.
The global $186m voluntary carbon market relies on businesses and individuals to self-regulate their emissions by buying offsets in the absence of a global climate pact.
For example, firms buy carbon credits from clean energy projects to offset emissions from energy use or business travel.
The volume of offsets bought by FTSE 100 companies accounts for 6% of the global voluntary carbon market.
Based on publicly available data from 2009-2010, the report found that 61% of FTSE 100 companies in the financials sector offset at least some of their emissions.
But no offsetting is happening in other low-carbon intensity sectors such as IT, healthcare or telecommunications.
"Lack of voluntary action from these companies, plus sectors with medium/high carbon intensity, means only 0.1% of FTSE 100 carbon emissions are being voluntarily offset," the report said.
High intensity companies are mostly covered by government regulation but medium intensity firms such as hotels and travel companies could do more to offset their emissions.
"These firms would make a large impact by reducing emissions and looking carefully at their direct emissions, supply chain and consumer use of products to see what part offsetting could play," the report added.
If all low intensity companies became carbon neutral, offset volumes would increase by 39 million tonnes a year and almost double the size of the voluntary market from the current 45 million tonnes, Carbon Retirement said.