Correction appended.

Congress is on the hunt for cash to offset Republicans' planned tax cuts.

One highly contentious source lawmakers are eyeing: revenue from opening up the Arctic National Wildlife Refuge to oil and gas drilling.

The fight over whether to open a 1.5-million-acre section of ANWR's coastal plain has played out before and has always been divisive. This attempt — the first major one in 13 years — will be no different.

Here's what you need to know as the debate heats up (again):

What is ANWR?

A 19.6-million-acre wildlife refuge located in the northeastern corner of Alaska. The South Carolina-sized swath of mountains and tundra is home to more than 250 species.

Even its acronymous nickname (pronounced an-wahr) speaks to the controversy surrounding the region, which has been at the center of a debate since its founding more than 35 years ago. Environmentalists say the abbreviation connotes the region's oil and gas potential rather than its wildlife and cultural value by divorcing it from the words "wildlife" and "refuge."

The battle lines

Pro-drilling: Republican lawmakers led by the Alaska delegation, state politicians in Alaska, the Trump administration, and the oil and gas industry.

Anti-drilling: environmental groups, congressional Democrats and some Alaska Natives.

Today, both sides say things are different from the last time Congress took up this fight in the mid-2000s, and both believe they can win.

Proponents say recent major oil discoveries and successfully executed projects on nearby state lands prove there is both demand and the know-how to drill in the Arctic. Money from oil and gas development is an important source of income in Alaska, which has suffered from recent fiscal woes as the price of oil has plummeted. Interior Secretary Ryan Zinke has also prioritized drilling in ANWR, citing possible revenues to federal coffers totaling $1.8 billion over the next decade.

Opponents of drilling in the coastal plain point to the very vehicle in which Congress is trying to open it up — through the special budget reconciliation process that requires just 51 votes in the Senate — as evidence that through traditional channels they still do not have the political will to drill in the Arctic refuge. They say revenue estimates are vastly overblown, drilling is too big of an ecological risk and the greenhouse gas emissions would hurt Alaska — which is warming at a rate 2.5 times the global average.

The backstory

When National Park Service scientists Lowell Sumner and George Collins visited the Brooks Range mountains in the early 1950s, they were struck by the remoteness of the wilderness of northeastern Alaska.

"This area offers what is virtually America's last chance to preserve an adequate sample of the pioneer frontier, the Stateside counterpart of which has vanished," Collins wrote in a 1953 paper titled "Northeast Arctic: The Last Great Wilderness," published in the Sierra Club Bulletin.

Soon after their visit, Wilderness Society President Olaus Murie and his wife, Margaret, along with other conservationists and scientists, began exploring the region and subsequently advocated for it to be placed under federal protection.

In December of 1960, then-Interior Secretary Fred Seaton signed an order protecting the 8.9-million-acre Arctic National Wildlife Range, calling it "one of the world's great wildlife areas." In 1980, President Carter went further, signing the Alaska National Interest Lands Conservation Act, which created the 19.6-million-acre Arctic National Wildlife Refuge with the modern boundaries and name it's known by today. The act also designated 8 million acres of ANWR as wilderness and thus off-limits to human settlement, and directed that the 1002 area — the 1.5 million acres of coastal land between the Brooks Range and the Beaufort Sea — could be surveyed for possible oil and gas resources.

The law left the decision over whether to allow drilling inside the 1002 area up to Congress, a deal conservationists often called the "great compromise."

Since then, Congress has remained split over whether to authorize drilling. In recent years, the lawmakers have tried to both open up ANWR and declare the 1002 area a wilderness area through traditional legislative proposals.

President Clinton in 1995 vetoed a measure that would have allowed drilling in ANWR. A follow-up attempt a decade later — led by then-Sen. Ted Stevens (R-Alaska) — was killed in large part because of the objections of a sizable bloc of moderate House Republicans.

What's the latest?

There are multiple reasons to believe congressional Republicans have their sights set on collecting revenue from ANWR drilling.

An August 2012 Congressional Budget Office report estimated the government would collect roughly $5 billion in the first 10 years after opening ANWR to energy development. That number mirrors the House's budget resolution, which directs the House Natural Resources Committee to find $5 billion in savings over the next decade as part of tax reform (Greenwire, Oct. 5).

Also this month, the Senate Budget Committee adopted a partisan fiscal 2018 budget plan that contains instructions to the ENR panel to find $1 billion in savings over the next decade to offset tax cuts (E&E Daily, Oct. 6).

ENR Chairwoman Lisa Murkowski (R-Alaska) has said she will write legislation to open up ANWR to help her committee meet that $1 billion savings (E&E Daily, Oct. 4).

Just how much oil?

It remains an open question exactly how much oil — and therefore revenue — could come from drilling in the coastal plain of ANWR, in part because it's been nearly two decades since the U.S. Geological Survey has conducted a resource assessment of the area.

In 1998, USGS released its last report on the region, estimating ANWR's northern plain is likely to contain a mean volume of 10.4 billion barrels of oil.

A recent spate of major oil and gas discoveries from companies operating in the federally managed National Petroleum Reserve-Alaska and on state lands has bolstered hope for a drilling renaissance, but there has been no new seismic data from ANWR since a series of 2-D studies were conducted in 1984 and 1985 (Energywire, May 30).

In its most recent budget proposal, the Trump administration stated leasing in the 1002 area could raise $1.8 billion by 2027, although the White House included no details on how that estimate was reached. In a document from the "Major Savings and Reforms" portion of the budget sent over by an Office of Management and Budget spokeswoman, the administration said it expects "revenues would initially be derived from bonus bids during the lease sales."

Not everyone agrees there is billions of dollars currently locked up in the Arctic refuge. An analysis released last week by the Center for American Progress estimates drilling in the 1002 area would bring in a much more conservative figure of $37.5 million over the next 10 years.

Would anyone drill?

There is also a question of whether anyone would be interested with oil prices hovering around $40 a barrel.

"We didn't believe it then, and we don't know that passing drilling in our crown jewel of our public lands system would lower gas prices for constituents, but that was the political backdrop in 2005," said Lydia Weiss, government relations director for lands with the Wilderness Society. "We haven't found an office yet that is reporting 'Please help us lower gas prices' phone calls in 2017. That's not part of the discussion now."

Alaska Department of Natural Resources Commissioner Andy Mack said his office gets asked if there would be demand for leases in the coastal plain all the time, and he believes there would be strong demand if the region was opened up for development.

"All you have to do is look back to the last lease sale the state of Alaska held," he said. Last December, the state had its second-largest lease sale by acreage and third by dollar amount since 1998, raking in nearly $17 million in winning bids on nearly 600 million acres of state lands in the North Slope.

Kara Moriarty, president and CEO of the Alaska Oil and Gas Association, said opening up the coastal plain would unlock job benefits for Alaskans and invigorate the oil and gas industry, an anchor of the state's economy.

In the years since the last vote on ANWR, she said oil and gas development on state lands has expanded to border the Arctic refuge on the east, bringing infrastructure closer to the region. Technology has gotten better and the footprint of oil and gas development smaller.

She too rejects the argument that with low oil prices companies won't be interested in drilling in the 1002 area.

"The reality is companies don't plan on a two-to-three-year horizon, they plan for a 50-60-year one," she said. "These are long-term prospects, and they look at a long-range forecast, and we won't know if companies are interested until the government goes through the process to hold a lease sale."

Correction: A previous version of this story misidentified the congressional committee charged with saving $5 billion over the next decade by the House budget resolution.

Reprinted from Climatewire with permission from E&E News. E&E provides daily coverage of essential energy and environmental news at