It could be an Earth Day like no other.
On Friday, the United States is expected to join China and about 160 other nations as the first to sign the landmark global climate agreement reached in Paris in December. The accord is widely viewed as an imperfect but essential first step if the world is going to prevent a future of rising seas, devastating heat, extreme weather and the human upheaval they would cause.
For President Obama, the moment marks a triumph in his efforts to combat climate change. His administration has increased investments in wind and solar power, led efforts to reduce power-plant and auto emissions, halted new coal leasing and backed away from offshore oil drilling in the Atlantic. Every few weeks seem to yield a new initiative.
Yet even as the administration says it wants to lead the world on climate, it is stumbling on the home front — facing challenges from those who say it goes too far or not far enough.
The centerpiece of Obama's climate agenda — the Clean Power Plan to limit greenhouse gas emissions from power plants — is in limbo as the Supreme Court weighs a challenge from states and industries that say the Environmental Protection Agency lacks the legal authority to carry out the plan. Even if it survives, scientists say much more needs to be done to meet emissions reductions stipulated in the Paris agreement — reducing greenhouse gas emissions from 26% to 28% below their 2005 levels by 2025.
In Utah, lawmakers recently approved a byzantine and controversial plan that depends on $53 million in federal money to export Utah coal to Asia, and the state appears unconcerned that the government would try to stop it even though exporting coal to other countries appears to conflict with the administration's climate goals. The money comes from royalties paid to the government for mining on federal land, a law that falls under the Mineral Leasing Act of 1920.
"There's no risk to the state," Stuart Adams, a state senator who helped push the measure through, said in an interview.
In Wyoming, officials recently acknowledged problems with their use of "self-bonding" to ensure that mining companies, many of which have declared bankruptcy, will pay to restore land they damage. Critics say the government could be forced to pay to clean up old mines or risk leaving huge gashes across the landscape.
Wyoming officials say they acted legally under federal law. Federal officials contend that only Congress can change the policy.
Meanwhile, a coal company in the region's Powder River Basin wants to expand one of the largest mines in the world — and the federal government is fighting for its right to do just that. The Justice Department is helping the Bureau of Land Management argue that the expansion will not have meaningful greenhouse gas impacts.
Critics say such logic flies in the face of an administration plan announced in January to review federal coal leasing in part to determine climate effects.
The examples involve coal, but pick another topic — oil production, salmon habitat, endangered species — and it is easy to find a gap between the administration's stated ambitions and what is actually happening. In some cases, making changes would require action from a Republican-controlled Congress, an unlikely development. But the administration faces plenty of criticism too.
This month, a federal judge in Montana ruled that the U.S. Fish and Wildlife Service was guided by politics, not science, when it decided two years ago that the rare wolverine, a resident of the Rocky Mountains and north Cascades, did not warrant federal protection under the Endangered Species Act.
In a pointed 22-page ruling, Judge Dana Christensen of the federal district court in Montana took the agency to task, suggesting it made its decision in part because it was under "immense political pressure" from certain Western states.
"The listing decision in this case involves climate science, and climate science evokes strong reactions," the judge wrote.
In conclusion, he added, "no greater level of certainty is needed to see the writing on the wall for this snow-dependent species standing squarely in the path of global climate change."
It is not surprising that an operation as vast and layered as the federal government has policy conflicts. But experts say climate policy is particularly tangled when it plays out among agencies making decisions on whether, for example, to protect a species or to allow mining or oil production.
In a working paper released this month, experts at the Sabin Center for Climate Change Law at Columbia University found "major inconsistencies" in how federal agencies address climate change.
The paper examined whether federal environmental law requires agencies that are considering whether to allow fossil fuel projects on public land to weigh the emissions the project would create "downstream," such as the burning of the fossil fuels, and "upstream," such as the extraction of the fuels and transportation of them to market.
"This question is an essential one, because it can significantly affect the balance of costs and benefits of a proposed project and an agency's ability to justify the approval of the project in light of that balance," Jessica Wentz, the center's associate director and a coauthor of the paper, wrote in a blog post.
Wentz and her coauthor, Michael Burger, the center's executive director, determined that these emissions should be considered in most cases. Though they found that agencies are beginning to recognize the issue, they also concluded that that "there are major inconsistencies in the analytical approaches both within and across agencies."
Wentz said the White House's Council on Environmental Quality has issued draft guidelines for how agencies should review projects for climate impacts — but guidelines are not final and lack the force of law.
"The other limitation to it," Wentz said, "is that it just provides guidance on the assessment process. It isn't guidance that is intended to tell you, 'And if you conclude there are a lot of greenhouse gas emissions, you should not approve the project.'"
The administration has received plenty of praise from conservation groups too, even as they may push for change in specific areas. In an email response, a White House spokesman, Frank Benenati, referred to the Climate Action Plan the president announced in 2013 and said the administration "has been making steady progress in implementing the all-of-government approach to combating climate change." He singled out the review of the coal leasing program as well as a planned database to track carbon emitted from fossil fuels produced from public lands and new regulations to expand protection for habitat critical to endangered wildlife now and in the future because of climate change.
Benenati said the administration "has been pushing to reform federal programs that some have argued are inconsistent with its climate goals."
But several lawyers on opposite sides of the administration said they have been surprised by some of the positions taken by the government — and by the tenacity of its arguments.
Matthew Bishop, a lawyer with the Western Environmental Law Center, which opposed the government in the wolverine case, said that he has been frustrated with several decisions the government has made involving whether to protect species. On the other hand, Bishop said the Obama administration stands to improve its legacy through another branch of government — the judicial system, where those decisions are often challenged.
"As much as a disappointment as this administration has been in terms of the Department of the Interior and endangered species listings, the judges [Obama has] appointed have been fantastic," Bishop said. "And those are lifetime tenured appointments, so it's significant."
Such as Judge Christensen, who sent the administration back the drawing board to rethink the fate of the wolverine. He was appointed by Obama in 2011.