(Bloomberg) -- President Joe Biden is set to order fresh action to combat climate change -- with plans for blocking new oil leasing on federal land, prioritizing science in government decision-making and bringing world leaders together to address the threat.The policy plans and directives, some of which are expected as soon as Wednesday, were described by people familiar with the plans.A moratorium on the sale of new drilling rights on federal lands and waters will allow the government to review whether -- and how -- that energy development should take place. At the same time, Biden will embrace a goal of protecting at least 30% of U.S. land and ocean by 2030, according to two people familiar with the matter.A similar “30 by ‘30” conservation plan has been endorsed by Biden’s Interior secretary nominee, Representative Deb Haaland, as well as many prominent conservatives who say that kind of broad land protection can help fight climate change and save species from extinction.The administration is also preparing an executive order to marshal the federal government’s purchasing power by requiring that federal agencies -- including the U.S. Postal Service -- buy clean vehicles and renewable power, according to three people familiar with the matter, though the timing of that announcement wasn’t clear. Biden hinted at the plans Monday during remarks detailing White House plans to boost federal spending on U.S. products.“The federal government also owns an enormous fleet of vehicles, which we’re going to replace with clean electric vehicles made right here in America, by American workers,” Biden said, adding the move would create millions of jobs. “Together this will be the largest mobilization of public investment in procurement, infrastructure, and R and D, since World War II.”Biden is also expected to host world leaders in a climate summit on Earth Day, according to three people familiar with the matter, a sign of the new president’s commitment to not just rejoin the Paris carbon-cutting accord but also strengthen it. The U.S.-hosted meeting on April 22 could be virtual, one of the people said, similar to a United Nations climate summit in December.The president will direct federal agencies to rely on science in making decisions about federal policy and rules, said one person familiar with the matter. Scientists complained that research about climate change and public health were given short shrift under former President Donald Trump. In one of its final major policy actions under Trump the EPA imposed a rule limiting how the agency uses scientific studies with non-public data to guide its decisions on pollution limits and other policy.Biden is expected to lay out the foundation of his promised new Civilian Conservation Corps modeled after the work-relief programs President Franklin Delano Roosevelt created during the Great Depression. The program would give Americans jobs working on land restoration and climate resiliency.“A 21st century Civilian Conservation Corps is as close as we have to a silver bullet to address the climate, biodiversity, and unemployment crises facing our nation today,” Collin O’Mara, president of the National Wildlife Federation, said in a statement.The efforts build on orders Biden signed his first day in office, aimed at chipping away Trump-era regulations that eased limits on greenhouse gas emissions and sought to accelerate fossil fuel projects.Where last week’s orders -- canceling Keystone XL and rejoining the Paris climate accord -- were about clearing away Trump-era policies, Wednesday’s action aims at taking on the threat.“This is the visionary stuff” as Biden makes good on his assertion on the campaign trail that fossil fuels need to be phased out because they pollute, said Athan Manuel, director of the Sierra Club’s Lands Protection Program. “He’s walking the walk on climate and public lands and taking on the oil industry.”The White House didn’t respond to a request for comment.While the moves on drilling are aimed mostly at federal land, U.S. agencies could be tapped to examine ways they can promote private land conservation too, according to one person familiar with the matter.The leasing moratorium would not affect existing oil and gas leases or ongoing operations on federal lands and waters.However, it would block oil and gas companies from replenishing a reserve of drilling rights while the government undertakes a broad, one-year review of where the activity should be resumed and under what conditions -- if at all.The covered territory is a prime source of the nation’s oil and gas, generating about 22% of total U.S. crude supplies and 12% of U.S. natural gas in 2019, according to the Energy Information Administration. Leasing and development on the tracts also generates billions in revenue for federal, state and tribal governments.Energy CostEnvironmentalists argue the cost of that energy development is too great. The oil and gas extracted from federal lands and waters generate about 8% of U.S. greenhouse gas emissions. They argue that federal lands instead can be transformed into a weapon against climate change, by simply conserving it or using the territory to host wind farms and solar arrays.Biden is also expected Wednesday to detail plans on how he will fulfill a campaign pledge to target 40% of clean energy investments to disadvantaged communities, seize on climate change as a force for creating jobs, and stand up a government-wide task force dedicated to the issue.In addition, Biden is also set to highlight the national security threats of climate change -- a move that stands in stark contrast to the Trump administration’s efforts to downplay the crisis -- according to one person familiar with the matter.Harnessing the government’s roughly $600 billion a year in purchasing power is no small feat. The federal government operates nearly 10,000 buildings and a fleet of 645,000 vehicles.Mail Trucks“Federal procurement is one way to bring about the economies of scale you need to bring down the cost of many of the clean energy technologies that will be so critical to reducing greenhouse gas emissions,” said Elgie Holstein, a senior director with the Environmental Defense Fund. “Federal procurement is a pretty big part of the administration’s strategy for getting us off to a quick start in bringing back the momentum we lost in bringing down greenhouse gas emissions and creating new jobs in the clean energy sphere.”Just electrifying the U.S. Postal Service fleet -- which was exempt from Obama-era fleet fuel efficiency standards -- could deliver an immediate jolt. The postal service now operates more than 228,000 vehicles -- one of the largest civilian fleets in the world.And according to the USPS inspector general in 2014, the vehicles also hog fuel -- costing about $3,000 annually to keep in service and getting just 10 miles per gallon. Fueling the vehicles represents about half of the postal service’s entire energy consumption, according to the EIA.The Postal Service has been considering a broad replacement for years and was on track to choose a winning design from what was originally six prototypes early this year.Companies that could benefit from the moves include the Workhorse Group Inc., an Ohio-based startup offering a fully-electric option.(Updates with details about Civilian Conservation Corps in ninth paragraph.)For more articles like this, please visit us at bloomberg.comSubscribe now to stay ahead with the most trusted business news source.©2021 Bloomberg L.P.