MANILA, June 17 (Reuters) - The Asian Development Bank (ADB) said on Wednesday it will up its investment in clean energy to US$2 billion a year from 2013 to significantly dampen carbon growth and cut greenhouse gas emissions in the region.

The bank's investments in clean energy reached about $1.6 billion in 2008, and comprised more than half of its total energy portfolio, WooChong Um, director for sustainable infrastructure at ADB, said.

But non-government organisations criticised the ADB for engaging in double talk, saying the Manila-based development lender continues to fund coal-fired power plants in Asia even as it reiterates its support for clean energy.

Outside the ADB headquarters where a forum tackling climate change was held, a handful of protesters, some wearing alien costumes and carrying a "Take me to your leaders" banner, urged the Philippines and other Asian nations to adopt measures to combat global warming.

"It's hypocritical of the bank to sound the alarm on the climate crisis and at the same time fund the problem," Renato Redentor Constantino, head of the NGO Forum on the ADB, told Reuters.

But bank officials say the ADB only supports projects that use coal or other fossil fuels if these employ a technology that lessens use of the fuel.

"In China and India, we don't support anything that is less than super critical," said Um, referring to coal-fired power projects having at least 45 percent efficiency versus the traditional use of pulverised coal which translates to only 30 percent efficiency.

"So they get to use less coal for the same amount of energy," said Um, adding that energy demand among developing countries cannot be entirely met using renewable energy at present.

In the Philippines, ADB provided a $200 million loan last year to a unit of U.S.-based AES Corporation , the buyer of the 600-MW Masinloc coal-fired power plant north of Manila.

The ADB said in a statement its spending on clean energy projects was part of an energy efficiency initiative adopted four years ago when it set a target of $1 billion in annual investments.

"While $2 billion annually is a significant commitment, this represents only a fraction of the region's financing needs in the area of clean energy," ADB President Haruhiko Kuroda told a news conference.

"But we expect that this contribution will catalyse additional resources from the private sector carbon markets and other sources."

Developing Asia accounts for about a third of global greenhouse gas emissions.

"Unless urgent measures are taken to alter development patterns, the region's share could easily increase to 40 percent or higher by 2030," Kuroda said.

The bank said it had funded wind power projects in China and India, a biomass power facility in Thailand, hydropower initiatives in Bhutan, China and Vietnam, and a shift to energy-efficient lighting for low-income Philippine homes.

The ADB is also pushing projects to improve and expand energy-efficient mass transport systems, with such projects expected to cut Asia's fast-growing energy demand and trim its reliance on expensive fuel imports.