Data from Bloomberg New Energy Finance (BNEF) shows investments in clean energy totalled $61.5 billion, 32% less than the same period last year.
This means investments across the first two quarters of 2016 amounted to $116.4 billion, a 23% year-on-year decrease.
BNEF chairman Michael Liebreich said it was "almost certain" investments for 2016 on the whole would be lower than the "runaway" $348.5 billion total of last year.
The fall in investments has been most keenly felt in the Asia-Pacific region, specifically China, where the total fell 34% to $33.7 billion.
Middle East and Africa saw a 46% decrease in investments, while the Americas, excluding the US and Brazil, was down 63%. Brazil actually saw a 36% increase and the US fell only 5%, demonstrating the fall off in the rest of the region.
BNEF said the fall was down to shift in the solar market, with a move to smaller-scale projects that require less capex.
The biggest renewable energy project to secure financing in the second quarter was SSE's 588MW Beatrice offshore project in Scotland. The $3.9 billion project is supported by asset manager Copenhagen Infrastructure Partners and Chinese state-owned investment holding company State Development and Investment Corporation.