By Valerie Volcovici
WASHINGTON, Feb 27 (Reuters) - An explosion in the number of laws passed around the world aimed at confronting climate change in the last 20 years was hailed on Thursday as a step toward building support for a United Nations climate treaty to be negotiated in 2015.
Countries that together account for most global greenhouse gas emissions have passed nearly 500 laws since the Kyoto Protocol climate treaty was signed in 1992, with emerging economies leading many of the recent efforts, according to a report released by the Global Legislators Organisation (GLOBE) and the Grantham Research Institute at the London School of Economics.
Prior to the treaty, fewer than 40 laws addressing climate were on the books.
Much of the major legislative action on climate change in 2013 took place in countries like China and Mexico, whose economies are growing rapidly.
The report was launched on Thursday in Washington to an audience of over 100 legislators from 50 countries in the U.S. Senate's Kennedy Caucus Room.
The U.N. climate treaty to be negotiated next year is expected to consist of pledges of specific actions, or "contributions," from nearly 200 countries, aimed at reducing greenhouse gases.
Senator Edward Markey, a Massachusetts Democrat who had co-authored a comprehensive climate-change bill when he was a U.S. representative, said the study should encourage the U.S. Congress to enact its own climate legislation. The bill co-authored by Markey had passed the House of Representatives in 2009 but died in the Senate a year later.
"We need an international movement to pass climate legislation, and nowhere is that movement needed more than here in the United States," Markey said.
Others at the report's launch, including House Democratic leader Nancy Pelosi, said that with the U.S. House now controlled by Republicans and the Senate run by Democrats, efforts at legislation are likely to be stymied by policy gridlock.
"Action in Congress right now is unfortunately not in the cards," said Todd Stern, the U.S. State Department's special envoy on climate change and lead U.S. climate negotiator.
The U.S. will achieve emissions cuts through executive action taken by the administration, he added.
The United States is pushing for a new approach to the climate treaty; under the previous, the requirement for unanimous consent made it difficult to agree to any changes.
Among the requirements envisioned by the United States for countries' contributions to the global pact are that they conform to a common timeframe with other countries, and be specific, quantified and quantifiable.
The United States' vision also would rely on countries' domestic authorities enforcing their contributions, since Congress is unlikely to ratify any new international treaty.
U.N. climate chief Christiana Figueres said on Thursday it is too early to predict what governments will agree to at the 2015 climate summit in Paris.
"It is clear that they are going to have a draft in Paris that will be robust, give certainty and be politically digestible in all countries," she told reporters.
Several preliminary meetings of climate negotiators are on the agenda. The next will take place next month in Bonn, and in September, heads of state will be invited to participate in a high level climate summit hosted by U.N. Secretary General Ban Ki-moon in New York.
(Reporting by Valerie Volcovici; editing by Ros Krasny and Leslie Adler)