The climate bond market has grown by 20% over the last year, with a large part of the growth stemming from an increase in labelled green-bond issuances.

The Climate Bonds Initiative estimated that the market for climate-related bonds stands at nearly $600bn (€545bn), consisting of $531.8bn in unlabelled climate-aligned bonds and $65.9bn in labelled green bonds.

Sean Kidney, the organisation’s chief executive, said the development showed institutions could now invest in a “large and liquid” universe of fixed income holdings.

With more than 90% of bonds investment grade, the large majority of issuances – $418bn – relates to low-carbon transport projects, followed by clean energy projects, which account for 20% of the universe.

The remaining 10% is split between construction and energy-efficiency projects, waste, pollution and water-themed investments or agricultural and forestry-related developments.

Germany’s Kreditanstalt für Wiederaufbau was one of the largest issuers of labelled green bonds over the period surveyed, selling $4bn within its first year active in the green bond market.

The UK’s Transport for London, with all of its issuances falling within the climate bond sector, also issued £400m (€564m) worth of green bonds in 2015.

The number of green bonds trebled compared with 2013, from $11bn to $36.6bn.

The Climate Bonds Initiative said it was expecting total issuance to hit $70bn by the end of 2015.

The state of the market report, commissioned by the HSBC Climate Change Centre of Excellence, also found evidence of greater diversification in the types of bonds being offered.

It noted that the US state of Hawaii issued an asset-backed green bond, while BerlinHyp established the market for green covered bonds with a €500m issuance in May 2015.

The report laid out 10 steps to grow the market, throwing its weight behind the pooling of smaller-scale carbon-reducing projects, such as rooftop solar panels.

The securitisation market, it said, could boost activity in this area.

“This includes encouraging deal flow of green loans suitable for subsequent securitisation, supporting financial warehousing of loans and providing credit enhancement for securitisation issuance,” it said. 

“These supports can be made conditional on loans using standardised contracts. This would speed up the standardisation process for low-carbon assets such as energy-efficiency loans.”

Last year, the Climate Bonds Initiative conceded the climate bonds market was not quite developed enough to warrant the launch of dedicated indices