In Re: Polar Bear Endangered Species

United States Court of Appeals
FOR THE DISTRICT OF COLUMBIA CIRCUIT

Argued October 19, 2012 Decided March 1, 2013

No. 11-5219

IN RE: POLAR BEAR ENDANGERED SPECIES ACT LISTING AND
SECTION 4(d) RULE LITIGATION – MDL NO. 1993,

SAFARI CLUB INTERNATIONAL, ET AL.,
APPELLANTS

v.

KENNETH LEE SALAZAR, ET AL.,
APPELLEES

CENTER FOR BIOLOGICAL DIVERSITY, ET AL.,
INTERVENORS-APPELLEES

Consolidated with 11-5221, 11-5222, 11-5223

Appeals from the United States District Court
for the District of Columbia
(No. 1:08-mc-00764)

Murray D. Feldman argued the cause for appellants.
With him on the briefs were Bradley E. Meyen, Assistant
Attorney General, Office of the Attorney General for the State
of Alaska, John J. Jackson III, Douglas S. Burdin, Anna M.
Seidman, M. Reed Hopper, Theodore Hadzi-Antich, Damien
 2
S. Schiff, Marcy G. Glenn, and Christina F. Gomez. Craig D.
Galli entered an appearance.
Murray D. Feldman and Bradley E. Meyen were on the
brief for appellant State of Alaska.
Steven J. Lechner was on the brief for amicus curiae
Mountain States Legal Foundation in support of joint
appellants.
Katherine W. Hazard, Attorney, U.S. Department of
Justice, argued the cause for appellees. With her on the brief
were Meredith Flax and David C. Shilton, Attorneys.
Rebecca J. Riley, Brendan Cummings, Kassia Siegel,
Jason Rylander, and Howard M. Crystal were on the brief for
intervenor-appellees Center for Biological Diversity, et al.
Eric R. Glitzenstein and Benjamin H. Longstreth entered
appearances.
Before: GARLAND, Chief Judge, BROWN, Circuit Judge,
and EDWARDS, Senior Circuit Judge.
EDWARDS, Senior Circuit Judge: In 2005, the Center for
Biological Diversity petitioned the Secretary of the Interior
and the Fish and Wildlife Service (“FWS” or “agency”) to list
the polar bear under the Endangered Species Act (“ESA” or
“Act”). When a species such as the polar bear is listed as
either “threatened” or “endangered” under the Act, it is then
subject to a host of protective measures designed to conserve
the species. After a three-year rulemaking process, FWS
found that, due to the effects of global climate change, the
polar bear is likely to become an endangered species and face
the threat of extinction within the foreseeable future. See
generally Determination of Threatened Status for the Polar
Bear (Ursus maritimus) Throughout Its Range (“Listing
Rule”), 73 Fed. Reg. 28,212 (May 15, 2008). The agency thus
 3
concluded that the polar bear should be listed as a threatened
species. Id.
A number of industry groups, environmental
organizations, and states challenged the Listing Rule as either
overly restrictive or insufficiently protective of the polar bear.
These challenges were consolidated as a Multidistrict
Litigation case in the U.S. District Court for the District of
Columbia. After a hearing on the parties’ submissions, the
District Court granted summary judgment to FWS and
rejected all challenges to the Listing Rule. See generally In re
Polar Bear Endangered Species Act Listing and § 4(d) Rule
Litigation, 794 F. Supp. 2d 65 (D.D.C. 2011). Joint
Appellants filed a timely appeal to contest the District Court’s
judgment. They contend that the Listing Rule is arbitrary and
capricious under the Administrative Procedure Act (“APA”),
5 U.S.C. § 706(2)(A), and that FWS’s action should be
reversed because of a series of deficiencies in the rulemaking
process and the Listing Rule itself.
The appellate court’s task in a case such as this is a
“narrow” one. Motor Vehicle Mfrs. Ass’n of U.S., Inc. v. State
Farm Mut. Auto. Ins. Co., 463 U.S. 29, 43 (1983). Our
principal responsibility here is to determine, in light of the
record considered by the agency, whether the Listing Rule is a
product of reasoned decisionmaking. It is significant that
Appellants have neither pointed to mistakes in the agency’s
reasoning nor adduced any data or studies that the agency
overlooked. In addition, Appellants challenge neither the
agency’s findings on climate science nor on polar bear
biology. Rather, the principal claim advanced by Appellants is
that FWS misinterpreted and misapplied the record before it.
We disagree.
In rejecting this appeal, we are guided by the Supreme
Court’s admonition that “a court is not to substitute its
judgment for that of the agency,” id., particularly in cases
 4
where the issues “require[] a high level of technical
expertise,” Marsh v. Or. Natural Res. Council, 490 U.S. 360,
377 (1989). Given these considerations and the evident
thoroughness and care of FWS’s explanation for its decision,
we can only conclude, as did the District Court, that
Appellants’ challenges “amount to nothing more than
competing views about policy and science.” In re Polar Bear,
794 F. Supp. 2d at 69. Accordingly, we affirm the judgment
of the District Court.

I. Background
The District Court’s opinion contains an extensive
summary of the factual and procedural record, see id. at 71-
79, so it is unnecessary for us to recite all of that information
here. Instead, we offer the following background statement
for convenience and clarity.

A. The Endangered Species Act
Congress passed the ESA in 1973 “to provide a means
whereby the ecosystems upon which endangered species and
threatened species depend may be conserved, [and] to provide
a program for the conservation of such endangered species
and threatened species.” 16 U.S.C. § 1531(b). “The term
‘endangered species’ means any species which is in danger of
extinction throughout all or a significant portion of its
range . . . .” Id. § 1532(6). “The term ‘threatened species’
means any species which is likely to become an endangered
species within the foreseeable future throughout all or a
significant portion of its range.” Id. § 1532(20). The
Secretaries of Interior and Commerce are obligated to publish
and maintain a list of all species determined to be endangered
or threatened. Id. § 1533(c)(1). The Secretaries have
 5
delegated this authority to FWS and the National Marine
Fisheries Service, depending on the species at issue. 50 C.F.R.
§ 402.01(b).
The ESA empowers an “interested person” to petition the
appropriate agency for the listing of any species. 16 U.S.C.
§ 1533(b)(3)(A). Upon receiving such a petition, the agency
“determine[s] whether [the] species is an endangered species
or a threatened species because of any of the following
factors: (A) the present or threatened destruction,
modification, or curtailment of its habitat or range; (B)
overutilization for commercial, recreational, scientific, or
educational purposes; (C) disease or predation; (D) the
inadequacy of existing regulatory mechanisms; or (E) other
natural or manmade factors affecting its continued existence.”
Id. § 1533(a)(1) (emphasis added). The agency makes a
listing determination “solely on the basis of the best scientific
and commercial data available . . . after conducting a review
of the status of the species and after taking into account those
efforts, if any, being made by any State or foreign nation . . .
to protect such species.” Id. § 1533(b)(1)(A).

B. The Listing Rule
On February 16, 2005, the Center for Biological
Diversity petitioned the Secretary of the Interior to list the
polar bear as threatened under the ESA because of the effects
of global climate change on polar bear habitat. In re Polar
Bear, 794 F. Supp. 2d at 72. On December 21, 2006,
following peer review and multiple opportunities for public
comment, FWS completed a 262-page Status Review. See
generally SCOTT SCHLIEBE ET AL., RANGE-WIDE STATUS
REVIEW OF THE POLAR BEAR (URSUS MARITIMIS)
(Dec. 21, 2006). (The Status Review is posted on FWS’s
website at http://www.fws.gov/.) Shortly thereafter, on
 6
January 9, 2007, FWS published a proposed rule to list the
species as threatened; this action triggered a 90-day public
comment period. See generally 12-Month Petition Finding
and Proposed Rule to List the Polar Bear (Ursus maritimus) as
Threatened Throughout Its Range, 72 Fed. Reg. 1064 (Jan. 9,
2007).
During the course of the rulemaking process, FWS
sought the assistance of the U.S. Geological Survey
(“USGS”) in “collecting and analyzing scientific data and
developing models and interpretations that would enhance the
base of scientific data for [FWS’s] use in developing the final
decision.” Listing Rule, 73 Fed. Reg. at 28,235. USGS
produced “nine scientific reports that analyze and integrate a
series of studies on polar bear population dynamics, range-
wide habitat use, and changing sea ice conditions in the
Arctic.” Id. These reports were also subject to public
comment.
FWS published the final Listing Rule on May 15, 2008.
The Listing Rule concludes that “the polar bear is likely to
become an endangered species within the foreseeable future
throughout all of its range” and should therefore be listed as
threatened. Id. at 28,212.
The Listing Rule explains in detail the taxonomy,
evolution, and population of the species. Some of the
principal findings are as follows:
Polar bears evolved in sea ice habitats and as a result
are evolutionarily adapted to this habitat.
****
Over most of their range, polar bears remain on the
sea ice year-round or spend only short periods on land.
However, some polar bear populations occur in
 7
seasonally ice-free environs and use land habitats for
varying portions of the year.
****
Although polar bears are generally limited to areas
where the sea is ice-covered for much of the year, they
are not evenly distributed throughout their range on sea
ice. They show a preference for certain sea ice
characteristics, concentrations, and specific sea ice
features. Sea-ice habitat quality varies temporally as well
as geographically. Polar bears show a preference for sea
ice located over and near the continental shelf, likely due
to higher biological productivity in these areas and
greater accessibility to prey in near-shore shear zones and
polynyas (areas of open sea surrounded by ice) compared
to deep-water regions in the central polar basin. Bears are
most abundant near the shore in shallow-water areas, and
also in other areas where currents and ocean upwelling
increase marine productivity and serve to keep the ice
cover from becoming too consolidated in winter.
****
Polar bears are distributed throughout the ice-
covered waters of the circumpolar Arctic, and rely on sea
ice as their primary habitat. Polar bears depend on sea ice
for a number of purposes, including as a platform from
which to hunt and feed upon seals; as habitat on which to
seek mates and breed; as a platform to move to terrestrial
maternity denning areas, and sometimes for maternity
denning; and as a substrate on which to make long-
distance movements.
****
The total number of polar bears worldwide is
estimated to be 20,000-25,000. Polar bears are not evenly
 8
distributed throughout the Arctic, nor do they comprise a
single nomadic cosmopolitan population, but rather occur
in 19 relatively discrete populations. The use of the term
“relatively discrete population” in this context is not
intended to equate to the Act’s term “distinct population
segments.” Boundaries of the 19 polar bear populations
have evolved over time and are based on intensive study
of movement patterns, tag returns from harvested
animals, and, to a lesser degree, genetic analysis. The
scientific studies regarding population bounds began in
the early 1970s and continue today. [The Listing Rule
adopts] the use of the term “population” to describe polar
bear management units consistent with their designation
by the World Conservation Union-International Union
for Conservation of Nature and Natural Resources
(IUCN), Species Survival Commission (SSC) Polar Bear
Specialist Group (PBSG) with information available as
of October 2006, and to describe a combination of two or
more of these populations into “ecoregions.” . . .
Although movements of individual polar bears overlap
extensively, telemetry studies demonstrate spatial
segregation among groups or stocks of polar bears in
different regions of their circumpolar range. These
patterns, along with information obtained from survey
and reconnaissance, marking and tagging studies, and
traditional knowledge, have resulted in recognition of 19
relatively discrete polar bear populations. Genetic
analysis reinforces the boundaries between some
designated populations while confirming the existence of
overlap and mixing among others.
Id. at 28,212-15 (citations omitted).
The Listing Rule also explains that studies of the nineteen
polar bear populations have divided the species into four
“physiographically different functional groups or ‘ecoregions’
 9
in order to forecast future polar bear population status on the
basis of current knowledge of polar bear populations, their
relationships to sea ice habitat, and predicted changes in sea
ice and other environmental variables.” Id. at 28,217. The
Listing Rule then discusses the Archipelago, Seasonal Ice,
Divergent, and Convergent ecogregions in some depth. Id. at
28,217-19.
FWS cited three principal considerations in determining
that polar bears should be listed as a threatened species. First,
the polar bear depends on sea ice for its survival. Id. at
28,214. Second, sea ice is declining. On this point, the Listing
Rule states:
Polar bears evolved to utilize the Arctic sea ice niche and
are distributed throughout most ice-covered seas of the
Northern Hemisphere. We find, based upon the best
available scientific and commercial information, that
polar bear habitat – principally sea ice – is declining
throughout the species’ range, that this decline is
expected to continue for the foreseeable future, and that
this loss threatens the species throughout all of its range.
Therefore, we find that the polar bear is likely to become
an endangered species within the foreseeable future
throughout all of its range.
Id. at 28,212. Third, climatic changes have and will continue
to reduce the extent and quality of Arctic sea ice. See id. at
28,244.
FWS concluded that these findings satisfied two of the
statutory listing factors: (A) the threatened destruction of the
species’ habitat or range, id. at 28,275-77, and (D) the
inadequacy of existing regulatory mechanisms to preserve the
species, id. at 28,288.
 10
In aggregating data on climate change and sea ice, FWS
relied on a variety of published studies and reports, including
those of the Intergovernmental Panel on Climate Change
(“IPCC”). See id. at 28,212. FWS explained that
[t]he rapid retreat of sea ice in the summer and overall
diminishing sea ice throughout the year in the Arctic is
unequivocal and extensively documented in scientific
literature. Further extensive recession of sea ice is
projected by the majority of state-of-the-art climate
models, with a seasonally ice-free Arctic projected by the
middle of the 21st century by many of those models.
Id. at 28,292. Noting that sea ice had reached a record low in
the summer of 2007, FWS also explained that “[t]he
observational record indicates that current summer sea ice
losses appear to be about 30 years ahead of the ensemble of
modeled values, which suggests that a transition towards a
seasonally ice-free Arctic might occur sooner than the models
indicate.” Id. at 28,234.
The agency’s assessment of the species’ dependence on
sea ice derives from peer reviewed studies on polar bear
biology and behavior, observed polar bear demographics, and
population modeling. As noted above, FWS explained that the
bears are highly dependent on sea ice, “including as a
platform from which to hunt and feed upon seals; as habitat
on which to seek mates and breed; as a platform to move to
terrestrial maternity denning areas, and sometimes for
maternity denning; and as a substrate on which to make long-
distance movements.” Id. at 28,214. The Listing Rule
anticipates that changes to the polar bear’s habitat will soon
pose an existential threat to the species:
Productivity, abundance, and availability of ice seals, the
polar bear’s primary prey base, would be diminished by
the projected loss of sea ice, and energetic requirements
 11
of polar bears for movement and obtaining food would
increase. Access to traditional denning areas would be
affected. In turn, these factors would cause declines in the
condition of polar bears from nutritional stress and
reduced productivity. As already evidenced in the
Western Hudson Bay and Southern Beaufort Sea
populations, polar bears would experience reductions in
survival and recruitment rates. The eventual effect is that
polar bear populations would decline. The rate and
magnitude of decline would vary among populations,
based on differences in the rate, timing, and magnitude of
impacts. However, within the foreseeable future, all
populations would be affected, and the species is likely to
become in danger of extinction throughout all of its range
due to declining sea ice habitat.
Id. at 28,292-93.

C. The District Court’s Decision
Soon after publication of the Listing Rule, nearly a dozen
challenges were filed to contest FWS’s action. See In re Polar
Bear, 794 F. Supp. 2d at 77-78. Several plaintiffs argued that
the listing was unwarranted because the agency failed to
establish a foreseeable risk of extinction. Others argued the
opposite – that the species should have been listed as
endangered because it faced an imminent risk of extinction.
These actions were consolidated before the District Court as a
Multidistrict Litigation case.
The litigants filed cross-motions for summary judgment.
On October 20, 2010, the District Court held an initial hearing
on the parties’ cross-motions for summary judgment.
At that hearing, the [District] Court focused only on a
threshold question: whether it must review the agency’s
 12
interpretation of the ESA listing classifications under
step one or step two of the familiar framework set forth
in Chevron, U.S.A., Inc. v. Natural Resources Defense
Council, Inc., 467 U.S. 837 (1984). In a Memorandum
Opinion issued on November 4, 2010, the [District]
Court held that FWS had improperly relied on an
erroneous plain-meaning reading of the definition of an
endangered species that could not be upheld under step
one of Chevron. In re Polar Bear Endangered Species
Act Listing and § 4(d) Rule Litigation, 748 F. Supp. 2d
19, 29 (D.D.C. 2010). Finding that the term “endangered
species” under the ESA is instead ambiguous, the Court
remanded the Listing Rule to the agency “to treat the
statutory language as ambiguous.” Id.
In response to the [District] Court’s remand order, on
December 22, 2010, the federal defendants submitted the
agency’s memorandum of supplemental explanation. In
their Supplemental Explanation, FWS concluded that,
even treating the phrase “in danger of extinction” in the
definition of an endangered species as ambiguous, the
administrative record does not support a finding that the
polar bear qualified for endangered status at the time of
listing. Because the agency determined that the species is
likely to become endangered within the foreseeable
future, however, FWS reiterated that the polar bear met
ESA’s . . . definition of a threatened species at the time
of listing.
In re Polar Bear, 794 F. Supp. 2d at 79 (citations omitted).
The District Court held another hearing on February 23,
2011, after which it granted summary judgment in favor of
FWS. The District Court rejected all of the challenges to the
Listing Rule. See generally id. After a lengthy review of
Appellants’ arguments, the District Court concluded that it
was “simply not persuaded that [FWS’s] decision to list the
 13
polar bear as a threatened species under the ESA was arbitrary
and capricious.” Id. at 81. Appellants challenge this decision
and several conservation groups have intervened on behalf of
FWS.

II. Analysis
Appellants’ principal claim on appeal is that FWS
misapplied the statutory criteria for a listing decision by
ignoring or misinterpreting the record before it and failing to
articulate the grounds for its decision. In particular,
Appellants contend that: (1) FWS failed to adequately explain
each step in its decisionmaking process, particularly in linking
habitat loss to a risk of future extinction; (2) FWS erred by
issuing a single, range-wide determination; (3) FWS relied on
defective population models; (4) FWS misapplied the term
“likely” when it determined that the species was likely to
become endangered; (5) FWS erred in selecting a period of 45
years as the “foreseeable future”; (6) FWS failed to “take into
account” Canada’s polar bear conservation efforts; and (7)
FWS violated Section 4(i) of the ESA by failing to give an
adequate response to the comments submitted by the State of
Alaska regarding the listing decision. For the reasons
discussed below, we find these arguments meritless.

A. Standard of Review
We will uphold an agency action unless we find it to be
“arbitrary, capricious, an abuse of discretion, or otherwise not
in accordance with law.” 5 U.S.C. § 706(2)(A). This standard
applies to our review of ESA listing decisions. See Am.
Wildlands v. Kempthorne, 530 F.3d 991, 997 (D.C. Cir.
2008). Under the arbitrary and capricious standard, the
reviewing court determines whether the agency “considered
 14
the factors relevant to its decision and articulated a rational
connection between the facts found and the choice made.”
Keating v. FERC, 569 F.3d 427, 433 (D.C. Cir. 2009). “The
Supreme Court has explained that an agency acts arbitrarily or
capriciously if it ‘has relied on factors which Congress has not
intended it to consider, entirely failed to consider an important
aspect of the problem, offered an explanation for its decision
that runs counter to the evidence before the agency, or is so
implausible that it could not be ascribed to a difference in
view or the product of agency expertise.’” Am. Wildlands, 530
F.3d at 997-98 (quoting State Farm, 463 U.S. at 43). “The
scope of review under the ‘arbitrary and capricious’ standard
is narrow and a court is not to substitute its judgment for that
of the agency.” State Farm, 463 U.S. at 43. Deference is
especially warranted where the decision at issue “requires a
high level of technical expertise.” Marsh, 490 U.S. at 377. “In
a case like the instant one, in which the District Court
reviewed an agency action under the APA, we review the
administrative action directly, according no particular
deference to the judgment of the District Court.” Holland v.
Nat’l Mining Ass’n, 309 F.3d 808, 814 (D.C. Cir. 2002).

B. The Agency’s Decision
The Listing Rule rests on a three-part thesis: the polar
bear is dependent upon sea ice for its survival; sea ice is
declining; and climatic changes have and will continue to
dramatically reduce the extent and quality of Arctic sea ice to
a degree sufficiently grave to jeopardize polar bear
populations. See Listing Rule, 73 Fed. Reg. at 28,212. No part
of this thesis is disputed and we find that FWS’s conclusion –
that the polar bear is threatened within the meaning of the
ESA – is reasonable and adequately supported by the record.
 15
The Listing Rule is the product of FWS’s careful and
comprehensive study and analysis. Its scientific conclusions
are amply supported by data and well within the mainstream
on climate science and polar bear biology. Thirteen of the
fourteen peer reviewers to whom FWS submitted the
proposed rule found that it generally “represented a thorough,
clear, and balanced review of the best scientific information
available from both published and unpublished sources of the
current status of polar bears” and that it “justified the
conclusion that polar bears face threats throughout their
range.” Listing Rule, 73 Fed. Reg. at 28,235. Only one peer
reviewer dissented, “express[ing] concern that the proposed
rule was flawed, biased, and incomplete, that it would do
nothing to address the underlying issues associated with
global warming, and that a listing would be detrimental to the
Inuit of the Arctic.” Id.
As we discuss below, several of Appellants’ challenges
rely on portions of the record taken out of context and
blatantly ignore FWS’s published explanations. Others, as the
District Court correctly explained, “amount to nothing more
than competing views about policy and science,” on which we
defer to the agency. In re Polar Bear, 794 F. Supp. 2d at 69;
see also Am. Wildlands, 530 F.3d at 1000 (reviewing courts
must “avoid[] all temptation to direct the agency in a choice
between rational alternatives”).
Significantly, Appellants point to no scientific findings or
studies that FWS failed to consider in promulgating the
Listing Rule. At oral argument, Appellants’ counsel
acknowledged that Appellants do not claim that FWS failed to
use the “best scientific and commercial data available” as
required by 16 U.S.C. § 1533(b)(1)(A). See Oral Argument at
25:22. Rather, “Appellants merely disagree with the
implications of the data for the species’ continued viability.”
Br. of Appellees at 14.
 16
Where, as here, the foundational premises on which the
agency relies are adequately explained and uncontested,
scientific experts (by a wide majority) support the agency’s
conclusion, and Appellants do not point to any scientific
evidence that the agency failed to consider, we are bound to
uphold the agency’s determination. Therefore we affirm the
District Court’s decision to uphold the Listing Rule.
We now address in turn each of Appellants’ seven
principal claims that the Listing Rule is arbitrary and
capricious.
1. Adequacy of FWS’s Explanation
Appellants argue that FWS violated the APA and ESA by
inadequately explaining how the predicted decrease in habitat
would likely lead to such a dramatic population decline
causing the species to be endangered within the next 45 years.
See, e.g., Am. Radio Relay League, Inc. v. FCC, 524 F.3d 227,
241 (D.C. Cir. 2008) (holding that agency failed to justify its
rulemaking with “a discernible path [of reasoning] to which
the court may defer”). In particular, Appellants contend that
FWS did not explain how the projected habitat loss would put
the polar bear “in danger of extinction” in the foreseeable
future or how great a decrease in the current population would
constitute endangerment. Appellants rely on Defenders of
Wildlife v. Norton, which held that “the loss of a
predetermined percentage of habitat or range would [not]
necessarily qualify a species for listing,” in part because “[a]
species with an exceptionally large historical range may
continue to enjoy healthy population levels despite the loss of
a substantial amount of suitable habitat.” 258 F.3d 1136, 1143
(9th Cir. 2001). Therefore, “the percentage of habitat loss that
will render a species in danger of extinction or threatened
with extinction will necessarily be determined on a case by
case basis.” Id.
 17
Appellants’ claim fails because FWS clearly explained
how the anticipated habitat loss renders this particular species
likely to become endangered. The agency considered and
explained how the loss of sea ice harms the polar bear. See,
e.g., Listing Rule, 73 Fed. Reg. at 28,275 (as a result of ice
loss, “polar bears will face increased competition for limited
food resources, increased open water swimming with
increased risk of drowning, increasing interaction with
humans with negative consequences, and declining numbers
that may be unable to sustain ongoing harvests”). The agency
also considered the observed demographic trends in the areas
where habitat loss has been most severe. For example, the
Western Hudson Bay population – which “occurs near the
southern limit of the species’ range” in an area without year-
round sea ice – has been in decline. Id. at 28,267. Numerous
experts predict that the sea ice loss in that area will soon
weaken female polar bears to the point where reproduction
levels become negligible. Id. at 28,266-67. And climatologists
anticipate that climatic changes will eventually affect all
Arctic sea ice, causing FWS to predict “reduced numbers and
reduced distributions of polar bears range-wide.” Id. at
28,276.
The agency’s decision was thus nothing like the situation
described in Defenders of Wildlife. Here the agency carefully
and clearly explained how this particular habitat loss leaves
this particular species likely to become endangered. The
Listing Rule not only provides “a discernible path” of
decisionmaking to which we must defer, Am. Radio, 524 F.3d
at 241, but it also firmly “articulate[s] a rational connection
between the facts found and the choice made.” Keating, 569
F.3d at 433.
2. Species’ Status Range-wide
Two of the Joint Appellants also argue that even if
certain polar bear populations are threatened, FWS was wrong
 18
to conclude that the species is threatened throughout its range.
They point to the agency’s description of the Archipelago and
Convergent ecoregions, both of which, FWS notes, are
somewhat insulated from seasonal melting by various
geophysical features. The ice in the far-northern Archipelago
ecoregion is protected by “the buffering effects of the island
archipelago complex, which lessens effects of oceanic
currents and seasonal retractions of ice and retains a higher
proportion of heavy more stable, multi-year sea ice.” Listing
Rule, 73 Fed. Reg. at 28,276. The Convergent ecoregion,
because of generalized ice drift, “accumulates ice . . . as it is
moved from the polar basin Divergent Ecoregion.” Id. at
28,218. As a result, this area “is characterized by heavy multi-
year ice.” Id. Consequently, polar bear populations in both
regions are not forecasted to decline as precipitously as those
in the two more vulnerable ecoregions. Id. at 28,248.
Appellants seize on these projections to argue that the agency
overreached by listing the entire species.
The agency considered comments along those lines and
provided an adequate response. See, e.g., id. at 28,240-41.
FWS acknowledged that receding sea ice may affect some
polar bear populations later than others. Id. However, the
agency also explained that much of this region is
limited . . . in its ability to sustain a large number of polar
bears because: (1) changes in the extent of ice and
precipitation patterns are already occurring in the region;
(2) the area is characterized by lower prey
productivity (e.g., lower seal densities); and (3) polar
bears moving into this area would increase competition
among bears and ultimately affect polar bear survival. In
addition, a small, higher-density population of polar bears
in the Canadian Arctic would be subject to increased
vulnerability to perturbations such as disease or
accidental oil discharge from vessels.
 19
Id.
Moreover, FWS explained that “accepted climate
models” predict sea ice loss throughout the Arctic and
anticipate that all polar bear populations will be affected. Id.
at 28,248-49. The undisputed record indicates that sea ice is
declining and is projected to continue declining throughout
the range, and the projected decline includes the Archipelago
and Convergent ecoregions. See id. at 28,240-41, 28,248-49,
28,271, 28,275-76. In 2007, sea ice losses in the Archipelago
and Convergent ecoregions were unprecedented. See id. at
28,220-21, 28,271, 28,276. “Arctic sea ice receded so much in
2007 that the so-called ‘Northwest Passage’ through the
straits of the Canadian Arctic Archipelago completely opened
for the first time in recorded history.” Id. at 28,220. FWS
found that, as a result of such developments, Arctic sea ice
declines were outstripping climate model projections. See id.
at 28,220, 28,271, 28,276. FWS explained that the 2007
record sea ice declines “are an extension of an accelerating
trend of minimum sea ice conditions and further support the
concern that current sea ice models may be conservative and
underestimate the rate and level of change expected in the
future.” Id. at 28,276.
The Listing Rule also indicates that, “[a]lthough climate
change may improve conditions for polar bears in some high
latitude areas where harsh conditions currently prevail, these
improvements will only be transitory. Continued warming
will lead to reduced numbers and reduced distribution of polar
bears range-wide.” Id. Relying on projections regarding sea
ice declines, FWS concluded that “the most northerly polar
bear populations will experience declines in demographic
parameters similar to those observed in the Western Hudson
Bay population, along with changes in distribution and other
currently unknown ecological responses.” Id. In light of this
record, FWS determined that, “ultimately, all polar bear
 20
populations will be affected within the foreseeable future, and
the species will likely become in danger of extinction
throughout all of its range.” Id. The best available science
suggests that some polar bear populations will remain at mid-
century; however, this does not undermine FWS’s decision to
list the species as threatened, but rather supports the agency’s
decision not to list it as endangered.
Appellants further argue that FWS should have divided
the species into Distinct Population Segments for the purposes
of this listing decision. See 16 U.S.C. § 1532(16) (“species”
includes “any distinct population segment of any species”). In
assessing polar bear populations, FWS applied its Policy
Regarding the Recognition of Distinct Vertebrate Population
Segments Under the Endangered Species Act (“DPS Policy”),
61 Fed. Reg. 4722 (Feb. 7, 1996). Appellants do not challenge
this policy. Instead, they merely argue that FWS misapplied it
in this case. Appellants carry a heavy burden in advancing
this claim because the agency’s interpretation of its own
regulations “must be given controlling weight unless it is
plainly erroneous or inconsistent with the regulation.” Thomas
Jefferson Univ. v. Shalala, 512 U.S. 504, 512 (1994).
The DPS Policy establishes three criteria for a Distinct
Population Segment, which the agency must assess
sequentially:
(1) Discreteness of the population segment in
relation to the remainder of the species to which it
belongs;
(2) The significance of the population segment to the
species to which it belongs; and
(3) The population segment’s conservation status in
relation to the Act’s standards for listing (i.e., is the
 21
population segment, when treated as if it were a species,
endangered or threatened?).
DPS Policy, 61 Fed. Reg. at 4725. “Discreteness” requires
that the population segment be either “markedly separated
from other populations of the same taxon as a consequence of
physical, physiological, ecological, or behavioral factors” or
“delimited by international governmental boundaries within
which differences in control of exploitation, management of
habitat, conservation status, or regulatory mechanisms exist
that are significant.” Id. FWS considered whether any of the
nineteen polar bear populations or four ecoregions satisfied
the terms of the DPS Policy and concluded that they did not.
In addressing the “markedly separated” criterion,
Appellants point to parts of the record that discuss some
differences between the relevant populations and ecoregions
in an effort to show that they are legally discrete. As FWS
explained, however,
there are no morphological or physiological differences
across the range of the species that may indicate
adaptations to environmental variations. Although polar
bears within different populations or ecoregions . . . may
have minor differences in demographic parameters,
behavior, or life history strategies, in general polar bears
have a similar dependence upon sea ice habitats, rely
upon similar prey, and exhibit similar life history
characteristics throughout their range.
Listing Rule, 73 Fed. Reg. at 28,294.
FWS also found only “small genetic differences” among
polar bears in different areas, indicating “extensive population
mixing associated with large home ranges and movement
patterns.” Id. Comment 51 in the Listing Rule asserts that
“[t]he 19 populations [FWS] has identified cannot be thought
 22
of as discrete or stationary geographic units, and polar bears
should be considered as one Arctic population.” Id. at 28,248.
In response, FWS stated:
We agree that the boundaries of the 19 populations are
not static or stationary. Intensive scientific study of
movement patterns and genetic analysis reinforces
boundaries of some populations while confirming that
overlap and mixing occur among others. Neither
movement nor genetic information is intended to mean
that the boundaries are absolute or stationary geographic
units; instead, they most accurately represent discrete
functional management units based on generalized
patterns of use.
Id. The bottom line is that the Listing Rule reasonably
concludes that physiology, demographics, behavior, and life
history strategies of the species are “not sufficient to
distinguish population segments under the DPS Policy.” Id. at
28,294.
Appellants also argue that the “international
governmental boundaries” criterion is satisfied because the
polar bear’s range encompasses several Arctic countries with
distinct management programs. Here too, the agency offered a
reasonable explanation that refutes Appellants’ contention:
Given that the threats to the polar bear’s sea ice habitat is
[sic] global in scale and not limited to the confines of a
single country, and that populations are being managed
collectively by the range countries (through bi-lateral and
multilateral agreements), we do not find that differences
in conservation status or management for polar bears
across the range countries is sufficient to justify the use
of international boundaries to satisfy the discreteness
criterion of the DPS Policy.
 23
Id.
While Appellants may disagree with FWS’s decision,
there is nothing in the record to suggest that the agency’s
decision to make a single, range-wide listing determination
was “plainly erroneous or inconsistent with” the DPS Policy.
Thomas Jefferson Univ., 512 U.S. at 512. Therefore, we reject
this challenge and hold that FWS’s conclusion that the species
warranted listing throughout its range was not arbitrary and
capricious.
3. The USGS Population Models
Appellants additionally challenge FWS’s reliance on two
polar bear population models developed by USGS. USGS
submitted nine scientific reports to assist FWS in developing
the Listing Rule. One of these reports presented two models
of projected polar bear population trends. See STEVEN C.
AMSTRUP ET AL., FORECASTING THE RANGE-WIDE STATUS OF
POLAR BEARS AT SELECTED TIMES IN THE 21ST CENTURY
(“AMSTRUP REPORT”) (2007). One model was “a
deterministic Carrying Capacity Model (CM) that applied
current polar bear densities to future . . . sea ice projections to
estimate potential future numbers of polar bears in each of the
4 ecoregions.” Listing Rule, 73 Fed. Reg. at 28,272. The other
was “a Bayesian Network Model (BM), [which] included the
same annual measure of sea ice area as well as measures of
the spatial and temporal availability of sea ice. In addition, the
BM incorporated numerous other stressors that might affect
polar bear populations that were not incorporated in the
carrying capacity model.” Id.
Citing these models’ limitations, Appellants argue that
FWS erred in relying on them. Appellants’ chief criticism of
the CM is its assumption that polar bear density will remain
constant over time, which USGS itself conceded was “almost
certainly not valid.” AMSTRUP REPORT at 12. Appellants
 24
argue that the BM was also unreliable, pointing to FWS’s
own characterization of the BM “as an ‘alpha’ level prototype
that would benefit from additional development and
refinement.” Listing Rule, 73 Fed. Reg. at 28,274.
“While courts routinely defer to agency modeling of
complex phenomena,” the agency must “explain[] the
assumptions and methodology used in preparing the model
and provide[] a complete analytic defense should the model
be challenged.” Appalachian Power Co. v. EPA, 249 F.3d
1032, 1053-54 (D.C. Cir. 2001) (per curiam); see also
Columbia Falls Aluminum Co. v. EPA, 139 F.3d 914, 923
(D.C. Cir. 1998) (“If . . . the model is challenged, the agency
must provide a full analytical defense.”). Appellants contend
that FWS has not done so here. This argument is plainly
meritless.
“That a model is limited or imperfect is not, in itself, a
reason to remand agency decisions based upon it.”
Appalachian Power, 249 F.3d at 1052. FWS explained the
methodology of the models within the Listing Rule itself, see
73 Fed. Reg. at 28,272-75, and FWS made available the full
Amstrup Report for public comment before the final rule was
promulgated, see id. at 28,235. The Listing Rule
acknowledges the limitations of these two models and
repeatedly explains that the agency only used them for the
limited purpose of confirming “the general direction and
magnitude” of the population trends already forecast on the
basis of other record evidence. Id. at 28,276. This is wholly
unlike Appalachian Power and Columbia Falls, where the
agency failed to explain how those models’ shortcomings did
not undercut the challenged rules. See Appalachian Power,
249 F.3d at 1053; Columbia Falls, 139 F.3d at 923.
It is also noteworthy that Appellants’ stance on these
models is self-contradictory. Despite challenging the models’
reliability, elsewhere in their briefs Appellants highlight
 25
USGS’s criticism that FWS did not rely on the models
enough. See Appellants’ Joint Br. at 21. Ironically, Appellants
cite to a USGS statement that says: “[w]hat we found to be
missing is a clear linkage between the [models’] forecasted
decline and the finding.” Id. (quoting General and Technical
Comments from USGS on the Draft Final Rule (Aug. 13,
2007)). In offering this citation, however, Appellants tellingly
omit USGS’s conclusion that
the outcomes from the [BM] are that polar bear
populations living in the Seasonal and Divergent
ecoregions are most likely extinct within the foreseeable
future.
General and Technical Comments from USGS on the Draft
Final Rule (Aug. 13, 2007). In other words, USGS was of the
view that the disputed models supported a stronger position
than FWS was prepared to take. Appellants’ claim, that FWS
blindly embraced the models and ignored their limitations, is
clearly false.
We hold that FWS’s narrow reliance on the USGS
population models was not arbitrary and capricious. FWS
understood and explained the models’ limitations and
carefully explained why its limited reliance on the models
was justified. As noted above, FWS only used the USGS
population models for the limited purpose of confirming “the
general direction and magnitude” of the population trends
already forecast on the basis of other record evidence. Listing
Rule, 73 Fed. Reg. at 28,276. In other words, it is absolutely
clear that the models were not central to FWS’s listing
decision.
4. FWS’s Standard of Likelihood
Appellants further claim that FWS imported into the
ESA’s listing standard, and then failed to apply, the IPCC’s
 26
definition of “likely.” The Act defines a threatened species as
“any species which is likely to become an endangered species
within the foreseeable future throughout all or a significant
portion of its range.” 16 U.S.C. § 1532(20) (emphasis added).
However, the term “likely” is not defined in the Act or by
regulation.
The IPCC defines “likely” as 67-to-90 percent certainty.
See INTERGOVERNMENTAL PANEL ON CLIMATE CHANGE:
FOURTH ASSESSMENT, SUMMARY FOR POLICYMAKERS 3 n.6
(2007). Appellants claim that FWS relied on this definition in
determining that the polar bear is likely to become an
endangered species. In support of this claim, Appellants point
to one place in the Listing Rule where FWS referenced the
IPCC definition in response to a peer review question. The
section to which Appellants point says: “The IPCC [Fourth
Assessment Report] assigns specific probability values to
terms such as ‘unlikely,’ ‘likely,’ and ‘very likely.’ We have
attempted to use those terms in a manner consistent with how
they are used in the IPCC [Fourth Assessment Report].”
Listing Rule, 73 Fed. Reg. at 28,237. Appellants contend that,
based on this limited reference to the IPCC, FWS embraced
the IPCC’s definition of “likely,” then ignored it, failed to
apply it to its assessment of the polar bear, and thus issued an
arbitrary and capricious decision. We disagree.
When the disputed section is read in context, Appellants’
argument is facially implausible. FWS’s reference to the
IPCC’s definition of “likely” seems related only to the
agency’s confidence in the climate forecasts, not to forecasts
on the species’ survival. The paragraph above the disputed
section is focused on “information on climate observations
and projections” and the views of “climate change scientists.”
Id. And the sentence immediately following the disputed
reference to the IPCC refers only to climate modeling. See id.
(“We have taken our best effort to identify the limitations and
 27
uncertainties of the climate models and their projections used
in the proposed rule.”). Furthermore, Appellants point to
nothing else in the Listing Rule to support their claim that
FWS relied on the IPCC definition in determining that the
polar bear is likely to become an endangered species.
In its brief to this court, FWS reasonably explains that the
agency interpreted the statutory reference to “likely” as
having its “ordinary meaning” or “dictionary definition.” Br.
of Appellees at 45-46. FWS essentially argues that there is
nothing in the Listing Rule to indicate that the agency bound
itself to the IPCC definition and thus meant to conclude that
“likely” means 69-to-90 percent certainty. We agree.
“A fundamental canon of statutory construction is that,
unless otherwise defined, words will be interpreted as taking
their ordinary, contemporary, common meaning.” Perrin v.
U.S., 444 U.S. 37, 42 (1979). FWS’s implicit understanding
of “likely” is consistent with the word’s ordinary definition.
Therefore, we do not accept the claim that FWS meant to
apply anything other than the commonplace definition of
“likely.”
Appellants argue in the alternative that FWS arbitrarily
and capriciously failed to apply any standard of “likelihood”
at all. This argument also fails. In a rulemaking an agency is
free to rely on common English usage without adopting
specialized definitions. The agency made a reasoned
determination that the species is “likely to become an
endangered species within the foreseeable future.” 16 U.S.C.
§ 1532(20). Appellants have not presented us with a single
case in which a court has struck down an ESA listing decision
because the agency declined to separate out and specially
define the term “likely.” Nor do we believe that FWS’s
decision not to expressly define “likely” has impeded our
ability to review the agency’s decisionmaking process. We
hold that the Listing Rule does not misapply the statutory
 28
term “likely,” as that term is commonly understood, and that
the agency action was not arbitrary and capricious on these
grounds.
5. FWS’s Standard of Foreseeability
The Act defines a threatened species as “any species
which is likely to become an endangered species within the
foreseeable future.” 16 U.S.C. § 1532(20) (emphasis added).
FWS considered the particular circumstances of this listing
decision and concluded that 45 years was the appropriate
foreseeable time period. See Listing Rule, 73 Fed. Reg. at
28,253-55. Appellants argue that FWS failed to justify its
definition of “foreseeable” as a 45-year period.
The term “foreseeable” is not defined by statute or
regulation. FWS determines what constitutes the
“foreseeable” future on a case-by-case basis in each listing
decision. See, e.g., 12-Month Finding on a Petition to List the
Siskiyou Mountains Salamander (Plethodon stormi) and Scott
Bar Salamander (Plethodon asupak) as Threatened or
Endangered, 73 Fed. Reg. 4380, 4381 (Jan. 24, 2008)
(defining the foreseeable future as 40 years based on FWS’s
ability to accurately anticipate threats to the species).
Appellants apparently reject FWS’s case-by-case approach
and claim that “‘the foreseeable future’ is the furthest period
of time in which [FWS] can reliably assess, based on
predicted conditions, whether the listing factors indicate that
the species likely will become ‘endangered.’” Appellants’
Joint Br. at 44. Appellants cite no legal authority suggesting
that FWS was bound to follow their preferred definition. In
any event, we conclude that, even applying Appellants’
formulation, FWS’s definition of foreseeability is reasonable.
FWS explained that “[t]he timeframe over which the best
available scientific data allows us to reliably assess the effect
of threats on the species is the critical component for
 29
determining the foreseeable future.” Listing Rule, 73 Fed.
Reg. at 28,253. “In the case of the polar bear, the key threat is
loss of sea ice, the species’ primary habitat.” Id. FWS looked
at the most widely accepted climate models, as compiled by,
among others, the IPCC. It found that there was general
agreement in these models about warming and sea ice trends
until about mid-century, at which point they diverge on the
basis of uncertainties about, inter alia, population growth,
technological improvements, and regulatory changes. See id.
(different models’ projections are fairly consistent until mid-
century “because the state-of-the-art climate models used in
[the IPCC’s Fourth Assessment Report] have known physics
connecting increases in [greenhouse gas concentrations] to
temperature increases through radiation processes, and the
[greenhouse gas] levels used in the [models’] emissions
scenarios follow similar trends until around 2040-2050”).
Appellants do not challenge the data underlying FWS’s
listing decision, but only FWS’s interpretation of that data.
That Appellants might have chosen a different period of
foreseeability is of no moment so long as the agency’s
decision was justifiable and clearly articulated. Here, we find
that FWS has not “relied on factors which Congress has not
intended it to consider, entirely failed to consider an important
aspect of the problem, [or] offered an explanation for its
decision that runs counter to the evidence before the agency,”
nor is the agency’s explanation “so implausible that it could
not be ascribed to a difference in view or the product of
agency expertise.” Am. Wildlands, 530 F.3d at 997-98
(quoting State Farm, 463 U.S. at 43).
Appellants also challenge FWS’s discussion of polar bear
biology as an alternative justification for the 45-year period of
foreseeability. Listing Rule, 73 Fed. Reg. at 28,254. We need
offer no opinion on the merits of Appellants’ scientific
critique because we conclude that the agency’s reliance on
 30
climate projections was sufficient to support their definition
of foreseeability. See id. (explaining that polar bear biological
considerations, such as reproductive cycles, were “not relied
on as the basis for determining ‘foreseeable future,’” even
though they provided “greater confidence for this listing
determination”).
6. Canada’s Polar Bear Conservation Efforts
The Act directs FWS to make listing decisions “solely on
the basis of the best scientific and commercial data
available . . . after conducting a review of the status of the
species and after taking into account those efforts, if any,
being made by any State or foreign nation . . . to protect such
species.” 16 U.S.C. § 1533(b)(1)(A) (emphasis added).
Appellants contend that FWS did not properly “take into
account” Canada’s polar bear conservation practices in
determining whether to list the species.
Appellants’ argument on this point is internally
inconsistent. At times, they construe the agency’s obligation
to “take into account” foreign conservation efforts as part of
its review of the “best scientific and commercial data
available.” See Appellants’ Joint Br. at 58. In other words,
they argue that foreign conservation efforts must be part of
the agency’s five factor analysis under 16 U.S.C.
§ 1533(a)(1). Under this interpretation, successful
international conservation efforts could conceivably offset
domestic habitat destruction, possibly obviating the need for a
listing decision on the basis of 16 U.S.C. § 1533(a)(1)(A).
On this view of the law, FWS clearly satisfied the
requirements of Act. The Listing Rule discusses the Canadian
harvest and export program at several points. See, e.g., Listing
Rule, 73 Fed. Reg. at 28,242. Ultimately, FWS concluded
there were no regulatory mechanisms in place, domestic or
international, that would “effectively address the primary
 31
threat to polar bears – the rangewide loss of sea ice habitat.”
Id. at 28,288. The Listing Rule’s discussion of these
conservation efforts and their inability to offset the likely
effects of habitat loss is sufficient for us to conclude that FWS
“considered the factors relevant to its decision and articulated
a rational connection between the facts found and the choice
made.” Keating, 569 F.3d at 433.
Appellants also advance a different argument: that the
agency has an “independent obligation” to “take into account”
foreign conservation efforts in addition to the five factors in
16 U.S.C. § 1533(a)(1). See Appellants’ Joint Br. at 53. FWS
addressed a similar contention in the Listing Rule. Comment
21 suggested that FWS “failed to consider the negative
impacts of listing on the long-term management of polar bears
developed in Canada that integrates subsistence harvest
allocations with a token sport harvest.” Listing Rule, Fed.
Reg. at 28,242. The agency replied in relevant part as follows:
Significant benefits to polar bear management in Canada
have accrued as a result of the 1994 amendments to the
[Marine Mammal Protection Act] that allow U.S. citizens
who legally sport-harvest a polar bear from an MMPA-
approved population in Canada to bring their trophies
back into the United States. These benefits include
economic revenues to native hunters and communities;
enhanced funding a [sic] support for research; a United
States conservation fund derived from permit fees that is
used primarily on the Chukchi Sea population; and
increased local support of scientifically-based
conservation programs. . . . [However] the Service must
list a species when the best scientific and commercial
information available shows that the species meets the
definition of endangered or threatened. The effect of the
listing, in this case an end to the import provision under
Section 104(c)(5) of the MMPA, is not one of the listing
 32
factors. Furthermore, the benefits accrued to the species
through the import program do not offset or reduce the
overall threat to polar bears from loss of sea ice habitat.
Id. (emphasis added). Whether or not FWS was required to
consider the negative impacts of its listing decision on
Canadian conservation efforts, the final sentence of the
above-quoted text indicates that it in fact did so. It concluded
that the benefits that accrued to polar bears from continued
importation of polar bear trophies from Canada were not
sufficient to undermine the basis for the listing decision. This
answer was enough, on its own, to dispose of the objection
raised.
7. Written Justification to the State of Alaska
The State of Alaska separately argues that FWS failed to
comply with Section 4(i) of the Act, which requires the
agency to provide a state with “a written justification for [its]
failure to adopt regulations consistent with the [state’s]
comments or petition.” 16 U.S.C. § 1533(i). Alaska submitted
detailed comments in response to both the proposed rule and
the nine USGS reports. On June 17, 2008, FWS responded
with a 45-page letter to Alaska specifically addressing the
State’s concerns. Alaska now maintains that this was
insufficient “written justification” for the agency action.
As a threshold matter, we reject FWS’s argument that
Alaska’s claim under Section 4(i) is not subject to judicial
review as part of the agency action. Like the District Court,
we construe Section 4(i) as “a procedural step that becomes
reviewable upon review of the final agency action (here, the
Listing Rule).” In re Polar Bear, 794 F. Supp. 2d at 115 n.59.
We further agree with the District Court that FWS
satisfied its obligations under Section 4(i) and that Alaska’s
claim plainly lacks merit. Alaska acknowledges that the
 33
written justification that it received from FWS was timely, but
asserts that its content was inadequate. The Act does not
indicate what the substance of a written justification must be.
We find, however, that under any reasonable reading of the
Act, FWS committed no error in its response to the concerns
raised by the State of Alaska.
The agency regulations state that:
If a State agency, given notice of a proposed rule . . .
submits comments disagreeing in whole or in part with
a proposed rule, and the Secretary issues a final rule
that is in conflict with such comments, or if the
Secretary fails to adopt a regulation for which a State
agency has made a petition . . . the Secretary shall
provide such agency with a written justification for the
failure to adopt a rule consistent with the agency’s
comments or petition.
50 C.F.R. § 424.18(c). When this regulation was promulgated,
FWS and the National Oceanic and Atmospheric
Administration – the two agencies that jointly administer the
Act – offered the following interpretation to amplify the
statutory requirement:
[A commenter] recommended that any justification
provided a State agency under § 424.18(c) be required
to, “. . . set forth the reasons that the State agency’s
position was rejected, in sufficient detail and with
sufficient supporting data, that the agency may have
an evidentiary basis for comparing its position with
that of the Secretary.” The Services do not believe that
Congress intended to establish such a strict standard
for justifications to State agencies. Rather, the
Services interpret this provision of the Act to provide
that State agencies be adequately informed of the basis
 34
for any action that is not in agreement with that
agency’s recommendation.
Amended Procedures to Comply with the 1982 Amendments
to the Endangered Species Act, 49 Fed. Reg. 38,900, 38,906
(Oct. 1, 1984).
The Services’ interpretation of the applicable regulation
commands no deference from this court. As the Supreme
Court has said, “[s]imply put, the existence of a parroting
regulation does not change the fact that the question here is
not the meaning of the regulation but the meaning of the
statute. An agency does not acquire special authority to
interpret its own words when, instead of using its expertise
and experience to formulate a regulation, it has elected merely
to paraphrase the statutory language.” Gonzales v. Oregon,
546 U.S. 243, 257 (2006). In other words, Gonzales indicates
that an agency’s interpretation of a regulation commands no
deference under Auer v. Robbins, 519 U.S. 452, 462 (1997),
or Thomas Jefferson University, 512 U.S. at 512, if the
regulation merely parrots the statute and the interpretation
does not itself carry the force of law warranting deference.
See Gonzales, 546 U.S. at 255-56 (holding that “deference . . .
is warranted only when it appears that Congress delegated
authority to the agency generally to make rules carrying the
force of law, and that the agency interpretation claiming
deference was promulgated in the exercise of that authority,”
and discussing United States v. Mead Corp., 533 U.S. 218,
226-27 (2001), and Chevron, U.S.A., Inc. v. Natural Res. Def.
Council, Inc., 467 U.S. 837, 842-45 (1984)). An agency
interpretation that commands no deference “is ‘entitled to
respect’ only to the extent it has the ‘power to persuade’.”
Gonzales, 546 U.S. at 256 (quoting Skidmore v. Swift & Co.,
323 U.S. 134, 140 (1944)).
We find that FWS’s interpretation of Section 4(i) was
eminently reasonable and, thus, “entitled to respect.”
 35
Skidmore, 323 U.S. at 140. FWS’s 45-page reply letter to
Alaska shows that “the Agency clearly thought about the
[State’s] objections and provided reasoned replies – all the
APA requires.” City of Portland v. EPA, 507 F.3d 706, 714
(D.C. Cir. 2007).
In its brief to this court, Alaska argues that FWS’s
written justification was deficient because the State disagreed
with the federal agency’s disposition of several substantive
issues in the Listing Rule. FWS’s letter to Alaska amplified
the basis for its positions on the disputed issues and, thus,
effectively addressed Alaska’s comments. Alaska does not
argue that FWS failed to give a timely response to the State’s
comments. Rather, Alaska simply disagrees with the
substantive content of FWS’s response. See, e.g., Alaska’s
Separate Br. at 12. (“[FWS] failed to adequately address these
concerns.”); id. at 13 (“[FWS] failed to adequately
respond. . . .”); id. (“[FWS] failed to provide the ‘adequate
written justification. . . .’”).
In requiring FWS to “submit to the State . . . a written
justification for [its] failure to adopt regulations consistent
with the [State’s] comments or petition,” Section 4(i) does not
mean to ensure that the State will be satisfied with FWS’s
response. Rather, Section 4(i) obviously is designed to allow
states to advance their particular sovereign concerns to ensure
that the federal agency has fully considered the applicable
state interests. Cf. Massachusetts v. EPA, 549 U.S. 497, 519-
20 (2007). FWS’s lengthy response to Alaska makes it clear
that the federal agency was fully aware of the State’s interests
and concerns and addressed them. That is all the Act required.
Indeed, even Alaska acknowledges that Section 4(i) is a
“procedural” rule, nothing more. See Alaska’s Separate Br. at
20. Thus, in assessing whether FWS satisfied the procedural
requirements of Section 4(i), we do not analyze the
sufficiency of FWS’s responses to Alaska’s comments. Cf.
 36
City of Portland, 507 F.3d at 714. Any challenges that Alaska
has to the substantive Listing Rule can be – and, indeed, were
– made in a challenge to the Listing Rule itself.
In sum, we hold that FWS plainly satisfied its duties
under Section 4(i) in responding to the State of Alaska. We
therefore affirm the judgment of the District Court on this
point.

III. Conclusion
For the reasons discussed above, we affirm the judgment
of the District Court.