At the opening of the recent U.N. talks in Poland, UNFCCC Executive Secretary Christiana Figueres said investment in CDM projects was dwindling and needed a boost.
"Unfortunately countries could not agree in Warsaw on any better way for funding," said Joseph Armathe Amougou, a Cameroonian delegate to the negotiations.
"Even proposals for green (climate) funds to be used to increase the price of CDM credits or to set a minimum price for CDM offset were rejected by Annex 1 countries (industrialised countries that are party to the Kyoto Protocol). This is not encouraging to investors in this area in developing countries," Amougou added.
Certified Emissions Reductions (CERs) - a unit representing one tonne of carbon dioxide-equivalent sequestered or abated - can be traded, and are purchased by industrialised countries to help meet their emissions reduction targets under the Kyoto Protocol, the main international treaty for curbing global warming.
But the price of CERs has dropped from more than 10 euros in 2011 to below 50 cents, due to over-supply and uncertainty over future demand.
"We in Africa need to cushion current CDM efforts - such as integrated bio-gas production in countries like Kenya - from ongoing and future shocks, instead of letting (the CDM) die at a time when it is beginning to function," said Robert Gichange from Kenya at an event organised by the PanAfrican Climate Justice Alliance on the sidelines of the Warsaw conference.
Some representatives of civil society groups said the creation of a special fund to support CDM projects - especially in Africa where they are suffering setbacks after a slow start - was imperative to revive investor interest.
"The private sector needs to be encouraged because this is the prime mover of any economy," said Agustine Njamnshi of the Cameroon branch of the Bioresources Development and Conservation Programme.
But some environmental experts in Cameroon believe all is not lost.
"Financing of climate change (activities) in developing countries today - be it mitigation or adaptation - has both the approach of carbon markets and that of carbon funds," said Zachee Nzohngandembou of the Centre for the Environment and Rural Transformation, a Cameroonian nongovernmental organisation.