Global issuance of green bonds through the first nine months of 2018 was essentially flat, Moody’s Investors Service announced Tuesday.

The New York-based rating agency reports that global issuers issued US$31.6 billion worth of green bonds in Q3 2018, down 30% from the US$45.2 billion issued in Q2 2018. As a result, the US$109.6 billion total issuance for the first nine months of the year was essentially in line with the same period last year, when issuance reached US$110.1 billion.

“August and September saw a significant slowdown in issuance, and the market remains below the pace needed to achieve our revised full-year forecast of US$175 billion to US$200 billion,” says Matthew Kuchtyak, analyst at Moody’s, in a statement.

Weakness in bond market conditions overall, combined with the growth of other categories, such as social and sustainability bonds, help explain the weak third quarter, Moody’s says.

“Although 2018 issuance is flat compared with 2017, interest in green bonds remains strong, and green bonds as a share of global bond issuance actually increased slightly for the first three quarters of 2018,” Moody’s says, and green bonds represent a 2.1% share of global issuance so far this year.