WASHINGTON - In the contest among Democratic candidates to prove their commitment to fight climate change, Bernie Sanders is going all in.

After watching most of his competitors present their own plans to reduce greenhouse gas emissions, Sanders released a $16.3 trillion “Green New Deal” Thursday that called for the U.S. power and transportation sectors to shift to 100 percent renewable energy by 2030. By 2050 he wants the U.S. economy powered solely by wind farms and solar panels, along with geothermal energy sources.

“Climate change is a global emergency,” said the Vermont senator. “The scientific community is telling us in no uncertain terms that we have no time left to transform our energy system away from fossil fuels to energy efficiency and sustainable energy.”

Two weeks before CNN hosts a candidate forum specifically on climate change, candidates are racing to shore up their clean energy bonafides.

Washington Gov. Jay Inlsee, who made climate the central issue of his campaign, had been a favorite among environmentalists. But with low polling numbers, he dropped out of the race Thursday, leaving the race for “greenest” candidate anyone’s to win.

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Sanders’ announcement Thursday was enough to land him a top spot on Greenpeace’s 2020 climate scorecard, sharing first place with Rep. Kristen Gillibrand, D-NY, who has called for shifting to 100 percent renewable energy within the decade.

“Voters across the country are demanding that the next president have a bold agenda to tackle the climate crisis and there is a lot to like in [Sanders’] plan,” said Tiernan Sittenfeld, senior vice president of government affairs at the League of Conservation Voters.

Sanders’ proposal stands in stark contrast to that presented by centrist Joe Biden, who is calling for net-zero emissions by 2050 — the point at which scientists warn the world must begin reducing the amount of carbon in the atmosphere to avoid the worst consequences of climate change.

Under such a plan, Texas’s oil and gas fields and other fossil fuel deposits could remain part of the economy, were carbon capture systems developed to prevent their emissions from being released into the atmosphere. And more nuclear reactors could be built. Both technologies scientists say will be critical to the global economy decarbonizing over the next three decades.

But Sanders proposal avoids both technologies all together.

“To get to our goal of 100 percent sustainable energy, we will not rely on any false solutions like nuclear, geoengineering, carbon capture and sequestration , or trash incinerators,” he said in his release.

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The aggressive move by Sanders comes as the Democratic Party is clashing with environmentalists on how mush attention to give the issue of climate change.

On Thursday, a Democratic National Committee panel denied a proposal to hold a debate strictly on climate change, after chairman Tom Perez argued if the panel did so, the DNC would then be obligated to hold more topic-specific debates in an already crowded debate schedule.

“The bar for action on climate change is set by science, not the DNC — and it isn’t getting any lower,” said John Noel, a senior campaigner with Greenpeace. “Tom Perez just doesn’t get it: we are in a climate emergency.”

james.osborne@chron.com

Twitter: @osborneja