The ratio was also higher than the 2.7 percent average that the member countries spent on environmental R&D activities out of their total national R&D budgets.
New Zealand topped the list with 13.39 percent, distantly followed by Canada`s 4.38 percent, Australia`s 4.11 percent and Spain`s 4.07 percent.
Portugal came in fifth with 3.69 percent, trailed by Hungary`s 3.52 percent, according to the report.
Russia, meanwhile, spent the smallest proportion of 0.14 percent for environmental research activities with spending by key countries like Switzerland, the Netherlands, the United States and Japan coming in lower than the 1 percent mark, the report noted.
Members` expense rates shown in the latest report reflect each country`s will to boost green sector growth rather than the actual environmental industry growth they achieved, the report said.
"Related R&D spending has been on the upturn as the importance of renewable energy and energy efficiency gained traction since the 1990s," the report said, adding that reflects growing jitters about global warming, energy price gains and the depletion of fossil fuels.
The organization pointed out that several countries started to assign massive financial investments to come up with technologies for mitigating mid-term climate changes. They are now focusing on boosting production of solar energy hydrogen fuel cells as well as electricity-powered vehicles, the OECD noted.