Full opinion text
MEMORANDUM OPINION EMMET G. SULLIVAN, District Judge. In May 2008, the U.S. Fish and Wildlife Service (“FWS” or “the Service”) issued its final rule listing the polar bear as a “threatened species” under the Endangered Species Act of 1973. See Determination of Threatened Status for the Polar Bear (Ursus maritivms) Throughout Its Range, 73 Fed.Reg. 28,212 (May 15, 2008) (the “Listing Rule”). The Service concluded that the polar bear is likely to become endangered within the foreseeable future because of anticipated impacts to its sea ice habitat from increasing Arctic temperatures, which have been attributed to global greenhouse gas emissions and related atmospheric changes. Numerous plaintiffs have challenged the Listing Rule under the Endangered Species Act (“ESA” or “the Act”), 16 U.S.C. §§ 1531-1544, and the Administrative Procedure Act (“APA”), 5 U.S.C. §§ 551-559, 701-706, claiming that the Service’s decision to list the polar bear as a threatened species was arbitrary and capricious and an abuse of agency discretion. Pending before the Court are the parties’ cross-motions for summary judgment. As the briefing in this case makes clear, the question of whether, when, and how to list the polar bear under the ESA is a uniquely challenging one. The three-year effort by FWS to resolve this question required agency decision-makers and experts not only to evaluate a body of science that is both exceedingly complex and rapidly developing, but also.to apply that science in a way that enabled them to make reasonable predictions about potential impacts over the next century to a species that spans international boundaries. In this process, the Service considered over 160,000 pages of documents and approximately 670,000 comment submissions from state and federal agencies, foreign governments, Alaska Native Tribes and tribal organizations, federal commissions, local governments, commercial and trade organizations, conservation organizations, nongovernmental organizations, and private citizens. In addition to relying on its own experts, the agency also consulted a number of impartial experts in a variety of fields, including climate scientists and polar bear biologists. In view of these exhaustive administrative proceedings, the Court is keenly aware that this is exactly the kind of decision-making process in which its role is strictly circumscribed. Indeed, it is not this Court’s role to determine, based on its independent assessment of the scientific evidence, whether the agency could have reached a different conclusion with regard to the listing of the polar bear. Rather, as mandated by the Supreme Court and by this Circuit, the full extent of the Court’s authority in this case is to determine whether the agency’s decision-making process and its ultimate decision to list the polar bear as a threatened species satisfy certain minimal standards of rationality based upon the evidence before the agency at that time. For the reasons set forth below, the Court is persuaded that the Listing Rule survives this highly deferential standard. After careful consideration of the numerous objections to the Listing Rule, the Court finds that plaintiffs have failed to demonstrate that the agency’s listing determination rises to the level of irrationality. In the Court’s opinion, plaintiffs’ challenges amount to nothing more than competing views about policy and science. Some plaintiffs in this case believe that the Service went too far in protecting the polar bear; others contend that the Service did not go far enough. According to some plaintiffs, mainstream climate science shows that the polar bear is already irretrievably headed toward extinction throughout its range. According to others, climate science is too uncertain to support any reliable predictions about the future of polar bears. However, this Court is not empowered to choose among these competing views. Although plaintiffs have proposed many alternative conclusions that the agency could have drawn with respect to the status of the polar bear, the Court cannot substitute either the plaintiffs’ or its own judgment for that of the agency. Instead, this Court is bound to uphold the agency’s determination that the polar bear is a threatened species as long as it is reasonable, regardless of whether there may be other reasonable, or even more reasonable, views. That is particularly true where, as here, the agency is operating at the frontiers of science. In sum, having carefully considered plaintiffs’ motions, the federal defendants’ and defendant-intervenors’ cross-motions, the oppositions and replies thereto, various supplemental briefs, the supplemental explanation prepared by FWS in response to this Court’s November 4, 2010 remand order, arguments of counsel at a motions hearing held on February 23, 2011, the relevant law, the full administrative record, and for the reasons set forth below, the Court finds that the Service’s decision to list the polar bear as a threatened species under the ESA represents a reasoned exercise of the agency’s discretion based upon the facts and the best available science as of 2008 when the agency made its listing determination. Accordingly, the Court hereby DENIES plaintiffs’ motions for summary judgment and GRANTS the federal defendants’ and defendant-intervenors’ motions for summary judgment, TABLE OF CONTENTS INTRODUCTION................................................................68 TABLE OF CONTENTS..........................................................70 I. BACKGROUND............................................................71 A. Statutory Background...................................................71 B. Factual and Procedural Background.......................................72 II. STANDARD OF REVIEW ..................................................79 III. DISCUSSION................................... 81 A. The Service Articulated a Rational Basis for Its Conclusion that the Polar _Bear Met the Definition of a Threatened Species at the Time of Listing......82 1. Plaintiff CBD’s Claim that the Polar Bear Should Have Been _Considered Endangered at the Time of Listing........................82 _a. The Service’s Findings ...........................................82 _b. Plaintiff CBD’s Arguments........................................85 _c. The Court’s Analysis.............................................87 _i. Standard of Review on Remand...............................87 _ii. Merits.....................................................89 2. Joint Plaintiffs’ Claim that the Polar Bear Should Not Have Been _Considered Threatened at the Time of Listing.........................90 a. Joint Plaintiffs’ Argument that the Service Failed to Demonstrate _that the Polar Bear Is 67-90% Likely to Become Endangered......91 b. Joint Plaintiffs’ Argument that the Service Arbitrarily Selected 45 Years As the “Foreseeable Future” Timeframe for the Polar _ Bear.........................................................93 B. The Service Articulated a Rational Basis for Its Conclusion that No Polar Bear Population or Eeoregion Qualifies As a “Distinct Population _Segment”............................................................96 _1. The Service’s Policy..................................................97 2. Plaintiffs CBD, SCI, and CF’s Claim that the Service Wrongly Concluded that No Polar Bear Population or Eeoregion Is _“Discrete”........................................................98 _3. The Court’s Analysis................................................100 _C. The Service Did Not Arbitrarily Fail to Consider Other Listing Factors.....101 1. Joint Plaintiffs’ Claim that the Service Failed to “Take Into Account” _Foreign Conservation Efforts to Protect the Polar Bear...............101 2. Joint Plaintiffs’ Claim that the Service Failed to Rely upon the “Best _Available Science”................................................104 a. Joint Plaintiffs’ Argument that Climate Science Is Too Uncertain _to Support the Service’s Conclusion .............................104 b. Joint Plaintiffs’ Argument that the USGS Population Models Do _Not Support the Service’s Conclusion............................106 c. Joint Plaintiffs’ Argument that the Service Ignored Scientific Data and Made Improper Findings Regarding the Southern _Beaufort Sea Population.......................................108 3. Plaintiff CBD’s Claim that the Service Failed to Consider Whether the Threat of Overutilization Warranted Listing the Polar Bear As _Endangered (“Listing Factor B”)...................................110 4. Joint Plaintiffs’ Claim that the Service Wrongly Concluded that Existing Regulatory Mechanisms Will Not Protect Polar Bears _despite Anticipated Habitat Losses (“Listing Factor D”)...............112 D. The Service Followed Proper Rulemaking Procedures ......................113 1. Plaintiff Alaska’s Claim that the Service Violated Section 4(i) of the ESA by Failing to Provide a Sufficient “Written Justification” in _Response to Comments............................................114 2. Plaintiff CF’s Claim that the Service Failed to Respond to Significant _Comments.......................................................116 IV. CONCLUSION............................................................116 1. BACKGROUND A. Statutory Background Congress enacted the ESA “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). An “endangered species” is “any species which is in danger of extinction throughout all or a significant portion of its range.” Id. § 1532(6). A “threatened species” is “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 term “species” is defined in the Act to include species, subspecies, and “any distinct population segment of any species of vertebrate fish or wildlife which interbreeds when mature.” Id. § 1532(16). The ESA requires the Secretary of the Interior to publish and maintain a list of all species that have been designated as threatened or endangered. Id. § 1533(c). Species are added to and removed from this list after notice and an opportunity for public comment, either on the initiative of the Secretary or as a result of a petition submitted by an “interested person.” Id. §§ 1533(b)(1), (3), (5). The Secretary of the Interior and the Secretary of Commerce are responsible for making listing decisions. Id. §§ 1532(15), 1533(a)(2). The Secretary of the Interior has jurisdiction over the polar bear. See 50 C.F.R. § 402.01(b). A listing determination is made on the basis of one or more of five statutorily prescribed factors: (a) the present or threatened destruction, modification, or curtailment of the species’ 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 the species’ continued existence. 16 U.S.C §§ 1538(a)(í)(A)-(E); see also 50 C.F.R. § 424.11(c). The agency must list a species if “any one or a combination” of these factors demonstrates that the species is threatened or The Secretary of the Interior has delegated his responsibilities under the Act to FWS. See 50 C.F.R. § 402.01(b). The Secretary of Commerce has delegated his responsibilities under the Act to the National Marine Fisheries Service (“NMFS”). See id. endangered. 50 C.F.R. §'424.11(c). The ESA further provides that the decision to list a species must be made 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, or any political subdivision of a State or foreign nation, to protect such species.... 16 U.S.C. § 1538(b)(1)(A). B. Factual and Procedural Background Polar bears are marine mammals that are described as “ice-obligate,” meaning that they are evolutionarily adapted to, and indeed completely reliant upon, sea ice for their survival and primary habitat. ARL 117259. They depend upon sea ice for critical functions such as hunting ice-dependent seals (their primary source of food), migrating between feeding areas and land-based maternity dens, and traveling long distances in search of mates or food. ARL 139259. Over most of their range, polar bears remain on the ice year-round. ARL 139245. The international Polar Bear Specialist Group — the authoritative source for information on the world’s polar bears — has identified nineteen polar bear populations located within five countries in the ice-covered regions of the Northern Hemisphere: the United States (in Alaska), Canada, Denmark (in Greenland), Norway, and Russia. ARL 117216-17,117219. On February 16, 2005, the Center for Biological Diversity submitted a petition to the Secretary of the Interior to list the polar bear as a threatened species under the ESA due to observed and anticipated declines in the Arctic sea ice upon which the polar bear reliés for survival. See generally ARL 4040-4209. FWS ultimately issued a final rule listing the polar bear as a threatened species on May 15, 2008. See generally ARL 117215-117307. At the time of listing, there were estimated to be approximately 20,000 to 25,000 polar bears worldwide, distributed throughout the species’ range. ARL 117219. These estimates further indicated that two of the nineteen polar bear populations were increasing in numbers (Viscount Melville Sound and M’Clintock Channel); six populations were stable (Northern Beaufort Sea, Southern Hudson Bay, Davis Strait, Lancaster Sound, Gulf of Boothia, Foxe Basin); and five populations were declining (Southern Beaufort Sea, Norwegian Bay, Western Hudson Bay, Kane Basin, Baffin Bay). ARL 117221. Insufficient data were available to identify trends for the remaining six populations (Barents Sea, Kara Sea, Laptev Sea, Chukchi Sea, Arctic Basin, East Greenland). ARL 117221. In its Listing Rule, FWS acknowledged that sea ice conditions across the Arctic had changed over the past several decades. ARL 117227-28. Specifically, the agency cited data indicating that the summer/fall ice melt season in the Arctic lengthened by approximately two weeks per decade between 1979 and 2005. ARL 117227. The agency also cited data indicating that September (i.e., minimum) sea ice extent was at an all-time low during the period between 2002 and 2007. ARL 117224. FWS further noted that scientists had observed significant recent declines in winter (i.e., maximum) sea ice extent, ARL 117226, cumulative annual sea ice extent, ARL 117226, and overall sea ice age and thickness, ARL 117226-27. Relying on complex climate models and related data from the International Panel on Climate Change (“IPCC”) — which FWS acknowledged to be the leading international body in climate change science— FWS attributed these changes in sea ice to increased Arctic temperatures caused by greenhouse gas emissions and related changes in atmospheric and oceanic circulation. ARL 117227-30. As FWS described, due to a reported lag time in response between when greenhouse gases are emitted into the atmosphere and when the impacts of those emissions are felt on the ground, the IPCC concluded that the global climate system is committed to a continued warming trend through the end of the 21st century. ARL 117233-34. Indeed, FWS noted that average projected warming levels through mid-century were generally consistent across all IPCC climate models, regardless of differences in possible emission levels over that period. ARL 117257. FWS looked also to IPCC models of Arctic sea ice, which similarly projected declines in ice extent through the end of the 21st century. ARL 117234. As FWS noted, the ten models that most accurately reflected historical sea ice changes prior to 2007 all projected a decline in September sea ice extent of over thirty percent (30%) by mid-century. ARL 117236-37. On the basis of these IPCC models and associated analysis, FWS concluded that it could confidently predict a significant decline in the polar bear’s sea ice habitat over the next 40 to 50 years. ARL 117279-81. FWS further concluded that the extent of anticipated declines in sea ice will significantly impact polar bear population health. ARL 117279. As FWS described, sea ice losses have been tied to nutritional stress in polar bears because of lower overall numbers of ice-dependent prey, decreased access to the prey that remain, shorter hunting seasons and longer seasonal fasting periods, and higher energetic demands from traveling farther and swimming longer distances across open water to reach sea ice. ARL 117279. FWS determined that this nutritional stress and other related factors will likely result in a decline in the physical condition of polar bears, leading to lower overall body weights and reduced cub survival rates. ARL 117270. FWS further found that consistent declines in physical condition and reproductive success will ultimately lead to population-level declines. ARL 117279. In reaching this conclusion, FWS relied in part on long-term studies showing that these impacts had already been observed in some of the southern-most polar bear populations. According to FWS, monitoring reports indicated that the Western Hudson Bay population — one of the longest-studied polar bear groups — had experienced declines in body condition among both adult male and adult female bears over the past three decades, with an associated population decrease of approximately twenty-two percent (22%). ARL 117271. FWS noted that this Canadian population also experienced significant declines in body mass among female bears over that period. ARL 117270. A comprehensive review of the polar bear’s status conducted prior to listing indicated that, between 1971 and 2001, the average date of spring break-up of the sea ice in the region advanced by three weeks, and temperatures increased by between 0.5°C and 0.8°C per decade. ARL 139286. The correlation between the timing of sea ice break-up and the body condition of adult female polar bears was found to be statistically significant. ARL 139286. The same polar bear status review also indicated that scientists monitoring the Southern Beaufort Sea polar bear population — another long-studied group — observed similar changes in body condition and unusual hunting behaviors. ARL 139279. As noted in the status review, population estimates for this group between 1986 and 2006 also showed declines, although researchers were not confident enough in these estimates to assert that the observed declines were statistically significant. ARL 139279. Prior to issuing its final rule, FWS commissioned the United States Geological Survey (“USGS”) to conduct additional scientific analysis related to the polar bear listing decision. Among other things, USGS undertook an effort to forecast the status of polar bears in different parts of the Arctic at three future time periods in the 21st century (i.e., 45 years, 75 years, and 100 years). See generally Forecasting the Range-Wide Status of Polar Bears at Selected Times in the 21st Century, ARL 161306-161436. USGS developed two models in an effort to predict potential future changes to polar bear population numbers across a range of scenarios, using climate models and the existing body of knowledge about polar bears. ARL 161313. A simple “carrying capacity” model was designed to estimate potential changes in numbers of bears based on current polar bear population densities and annual sea ice projections. ARL 161316. A more comprehensive “Bayesian Network” model was designed to determine the probability of certain population outcomes (e.g., “larger than now,” “same as now,” “smaller,” “rare,” or “extinct”), taking into account a wide range of factors including the seasonal availability of sea ice, as well as population stressors unrelated to sea ice loss. ARL 161317, 161325-26. For the purpose of these models, USGS grouped the nineteen global polar bear populations into four “ecoregions” — Seasonal Ice, Divergent Ice, Convergent Ice, and Archipelago — based upon regional patterns of ice formation. ARL 117276. The Seasonal Ice Ecoregion, for example, occurs at the southern end of the polar bear range and is ice-free for a portion of the year. ARL 117221. In the Divergent Ice Ecoregion, which is located mainly in Alaska, ice formed at the shore drifts away from land as a result of wind and ocean currents. ARL 117222. In the Convergent Ice Ecoregion, sea ice formed in the Divergent Ice Ecoregion moves toward land and collects at the shore. ARL 117222. The Archipelago Ecoregion, at the northernmost point of the Canadian Arctic, generally has thicker and more persistent ice year-round. ARL 117222. USGS determined that these variations in sea ice conditions generally correlate to differences in how polar bears interact with their sea ice habitat. ARL 117221. Consistent with IPCC climate and sea ice models, both of the USGS models projected population declines in all four polar bear ecoregions over the next 100 years. ARL 161312. The simple carrying capacity model indicated that polar bear population levels range-wide will have moderately decreased by year 45, assuming average projected levels of future sea ice. ARL 161331. Assuming minimal levels of future sea ice, the carrying capacity model projected trends “toward extirpation” of bears in the Divergent Ice Ecoregion by year 45 and in the Seasonal Ecoregion by year 75. ARL 161331. Similarly, according to USGS, the Bayesian Network model results suggested that “multiple stressors will likely play important and deleterious roles on all polar bear populations, even starting at year 45, and generally increase in their effect through year 100.” ARL 161332. For example, the Bayesian Network model projected an outcome of extinction for bears in the Seasonal and Divergent Ice Ecoregions by year 45 and for bears in the Convergent Ice Ecoregion by year 75. ARL 161312-13. In the Archipelago Ecoregion, a “smaller” population was the dominant outcome at year 45 under all scenarios. ARL 161332. In relying on the USGS population models, FWS emphasized that it had less confidence in the specific numerical outcomes of these models than in their “general direction and magnitude.” ARL 117278. Specifically, FWS pointed to several caveats that USGS itself identified in the development of these models. As FWS described, USGS acknowledged that the carrying capacity model only accounted for changes in sea ice extent and could not account for several other important factors, including seasonal ice fluctuations and other population stressors. ARL 117277. Further, USGS indicated that this simple model assumed a linear relationship between sea ice and numbers of bears, which is not necessarily the case, and it also assumed that polar bear density will not change over time, which “is almost certainly not valid.” ARL 161323. FWS similarly discounted the specific outcomes of the Bayesian Network model, which USGS described as a “first-generation ‘alpha’ level prototype,” ARL 161338, because it reflected the judgment of only one polar bear expert and “still must be vetted through other polar bear experts.” ARL 161338; see also ARL 117278. Insofar as these population models were generally consistent with the record as a whole, however, FWS found that these models supported a conclusion that sea ice losses will negatively impact polar bears in a significant way within the foreseeable future. ARL 117278; ARL 117300. Based on a voluminous administrative record, including the studies described above, and input from fourteen peer reviewers and numerous polar bear specialists, climate scientists, experts in Traditional Ecological Knowledge (“TEK”), state and federal agencies, foreign governments, Alaska Native tribes and tribal organizations, federal commissions, local governments, commercial and trade organizations, conservation organizations, nongovernmental organizations, and private citizens, FWS concluded that the polar bear was threatened throughout its range at the time of listing, within the meaning of the ESA. ARL 117296. Specifically, FWS determined that all polar bear populations will be affected by substantial losses of sea ice within the foreseeable future (which it defined as 45 years), although different populations will be affected at different rates and to different degrees. ARL 117279-80. FWS further found that polar bears are unlikely to adapt to these anticipated habitat changes. ARL 117264-66. However, notwithstanding these findings, FWS concluded that the polar bear was not endangered in any portion of its range at the time of listing. ARL 117301. The agency determined that at the time of listing the species was generally abundant throughout its range, the species continued to occupy the full extent of its historical range, and it had yet to experience precipitous population declines in any portion of its range. ARL 117299-301. Even in the Western Hudson Bay population, where a statistically-significant decline had been observed, the species continued to reproduce normally. ARL 117300. According to FWS, these countervailing facts demonstrated that the polar bear was not “in danger of extinction” at the time it made its listing decision, although the agency reiterated that the species would likely become an endangered species by mid-century. ARL 117301. The publication of the Listing Rule triggered lawsuits by a number of organizations and individuals: (1) the State of Alaska (“Alaska”) (State of Alaska v. Salazar, et al., No. 08-1352 (D.D.C. Aug. 4, 2008)); (2) Safari Club International and Safari Club International Foundation (collectively, “SCI”) (Safari Club Int’l, et al. v. Salazar, et al., No. 08-1550 (D.D.C. Sept. 8, 2008)); (3) California Cattlemen’s Association and the Congress on Racial Equality (collectively, “CCA”) (California Cattlemen’s Ass’n, et al. v. Salazar, et al., No. 08-1689 (D.D.C. Oct. 2, 2008)); (4) Center for Biological Diversity, Natural Resources Defense Council, and Greenpeace (collectively, “CBD”) (Ctr. for Biological Diversity, et al. v. Salazar, et al., No. 08-1339 (N.D. Cal. Mar. 10, 2008)); and (5) Conservation Force, the Inuvialuit Game Council, and numerous hunting and trapping organizations as well as individuals (collectively, “CF”) (Conservation Force, et al. v. Salazar, et al., No. 09-245 (D.D.C. Feb. 9, 2009)). These five actions were subsequently consolidated before this Court, along with six related actions, pursuant to an order of the Judicial Panel on Multi-District Litigation. See generally Certified Copy of Transfer Order, Docket No. I. Several groups intervened to defend against plaintiffs’ challenges to the Listing Rule. Specifically, this Court permitted the Alaska Oil and Gas Association (“AOGA”) and the Arctic Slope Regional Corporation (“ASRC”) to intervene as defendants in the challenge brought by plaintiff CBD. See Stipulation and Order Regarding Intervention, Docket No. 33, at 4-5. The Court also permitted SCI, a plaintiff in its own action, to intervene as a defendant in the action brought by plaintiff CBD. Plaintiff CBD was permitted to intervene as a defendant in the remaining challenges to the Listing Rule. On October 20, 2009, plaintiffs filed their motions for summary judgment. Among other claims, plaintiff CBD contends that the decision to list the polar bear as threatened was arbitrary and capricious because the polar bear met the definition of an endangered species under the ESA at the time of listing and thus qualified for a higher level of protection. The remaining plaintiffs (collectively, “Joint Plaintiffs”) contend, among other things, that the decision to list the polar bear was arbitrary and capricious because the polar bear did not meet the definition of a threatened species at the time of listing and therefore did not qualify for ESA protections. The federal defendants filed their cross-motion for summary judgment on December 7, 2009. See generally Federal Defendants’ Combined Opposition and Cross-Motion for Summary Judgment on Listing Rule Claims, Docket No. 137 (“Fed. Def. Mot.”). The various defendant-intervenors filed their cross-motions for summary judgment on January 19, 2010. This Court held an initial hearing on the parties’ cross-motions for summary judgment on October 20, 2010. At that hearing, the Court focused only on a threshold question: whether it must review the agency’s 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. 887, 104 S.Ct. 2778, 81 L.Ed.2d 694 (1984). In a Memorandum Opinion issued on November 4, 2010, the 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 § k(d) Rule Litigation, 748 F.Supp.2d 19, 29 (D.D.C.2010) [hereinafter In re Polar Bear ]. 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 Court’s remand order, on December 22, 2010, the federal defendants submitted the agency’s memorandum of supplemental explanation. See generally Supplemental Explanation for the Legal Basis of the Department’s May 15, 2008 Determination of Threatened Status for Polar Bears, Docket No. 237-1 (“Supp. Exp.”). 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 the definition of a threatened species at the time of listing. Supp. Exp. at 16. The Court gave the parties an opportunity to submit additional briefs responding to the agency’s supplemental explanation. See generally Joint Plaintiffs’ Response to Federal Defendants’ Supplemental Explanation, Docket No. 240 (“JP Supp. Mem.”); Plaintiff CBD’s Response to Federal Defendants’ Supplemental Explanation, Docket No. 241 (“CBD Supp. Mem.”); AOGA and ASRC Defendant-Intervenors’ Response to Federal Defendants’ Supplemental Explanation, Docket No. 239 (“AOGA Supp. Mem.”); Federal Defendants’ Supplemental Reply, Docket No. 242 (“Fed. Def. Supp. Reply”). A second motions hearing was held on February 23, 2011, during which the Court heard arguments on all plaintiffs’ Listing Rule claims. The parties’ cross-motions for summary judgment are now ripe for determination by the Court. II. STANDARD OF REVIEW The Service’s listing decisions are subject to review under the APA. See, e.g., Am. Wildlands v. Kempthome, 530 F.3d 991, 997 (D.C.Cir.2008). Under APA review, federal agency actions are to be held unlawful and set aside where they are “arbitrary, capricious, an abuse of discretion, or otherwise not in accordance with law.” 5 U.S.C. § 706(2)(A). To make this finding, a court must determine whether the agency “considered 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) (citing Balt. Gas & Elec. Co. v. Natural Res. Def. Council, Inc., 462 U.S. 87, 105, 103 S.Ct. 2246, 76 L.Ed.2d 437 (1983)). The standard of review under the APA is a narrow one. Citizens to Pres. Overton Park v. Volpe, 401 U.S. 402, 416, 91 S.Ct. 814, 28 L.Ed.2d 136 (1971). The court is not empowered to substitute its judgment for that of the agency. Id. Deference to the agency’s judgment is particularly appropriate where the decision at issue “requires a high level of technical expertise.” Marsh v. Or. Natural Res. Council, 490 U.S. 360, 375-77, 109 S.Ct. 1851, 104 L.Ed.2d 377 (1989); Ethyl Corp. v. EPA 541 F.2d 1, 36 (D.C.Cir.1976) (“[The court] must look at the decision not as the chemist, biologist or statistician that [it is] qualified neither by training nor experience to be, but as a reviewing court exercising [its] narrowly defined duty of holding agencies to certain minimal standards of rationality.”). Specifically, with regard to FWS decisions, this Court has previously recognized that “[g]iven the expertise of the FWS in the area of wildlife conservation and management and the deferential standard of review, the Court begins with a strong presumption in favor of upholding decisions of the [FWS].” Am. Wildlands v. Kempthorne, 478 F.Supp.2d 92, 96 (D.D.C.2007) (citing Carlton v. Babbitt, 900 F.Supp. 526, 530 (D.D.C.1995)). This narrow, deferential standard does not, however, shield the agency from a “thorough, probing, in-depth” review. Overton Park, 401 U.S. at 415, 91 S.Ct. 814. The court’s inquiry into the facts must be both “searching and careful.” Id. at 416, 91 S.Ct. 814. Administrative action must be invalidated as arbitrary where the agency 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. Motor Vehicle Mfrs. Ass’n v. State Farm Mut. Auto. Ins. Co., 463 U.S. 29, 43, 103 S.Ct. 2856, 77 L.Ed.2d 443 (1983). This determination must be made solely on the basis of the record before the agency when it made its decision. Camp v. Pitts, 411 U.S. 138, 142, 93 S.Ct. 1241, 36 L.Ed.2d 106 (1973). Where the court reviews an agency’s interpretation of a statute it is charged with administering, the Supreme Court’s opinion in Chevron provides the appropriate framework of review. The first step in this review process is for the court to determine “whether Congress has directly spoken to the precise question at issue.” Chevron, 467 U.S. at 842, 104 S.Ct. 2778. “If the intent of Congress is clear, that is the end of the matter; for the court, as well as the agency, must give effect to the unambiguously expressed intent of Congress.” Id. at 842-43, 104 S.Ct. 2778. In determining whether the statute unambiguously expresses the intent of Congress, the court should use all the “traditional tools of statutory construction,” see id. at 843 n. 9, 104 S.Ct. 2778, including looking to the text and structure of the statute, as well as its legislative history, if appropriate. See Bell Atlantic Tel. Co. v. FCC, 131 F.3d 1044, 1047 (D.C.Cir.1997). If the court concludes that the statute is either silent or ambiguous with respect to the precise question at issue, the second step of the court’s review process is to determine whether the interpretation proffered by the agency is “based on a permissible construction of the statute.” Chevron, 467 U.S. at 843, 104 S.Ct. 2778. The court must defer to agency interpretations that are not “procedurally defective, arbitrary or capricious in substance, or manifestly contrary to the statute.” United States v. Mead Corp., 533 U.S. 218, 227, 121 S.Ct. 2164, 150 L.Ed.2d 292 (2001) (citing Chevron, 467 U.S. at 843-14, 104 S.Ct. 2778). III. DISCUSSION Plaintiffs have identified a number of purported deficiencies in the Listing Rule, each of which forms the basis for a claim that FWS violated both the ESA and the APA when it listed the polar bear as a threatened species. Plaintiffs’ claims can be classified into three general categories. First, each of the plaintiffs in this case argues that the Service’s decision to list the polar bear as a threatened species was based on a fundamentally flawed interpretation of the ESA’s listing standards and a misguided application of the record evidence. Specifically, plaintiff CBD claims that FWS wrongly concluded that the polar bear did not qualify for endangered status at the time of listing, given the evidence in the record indicating that substantial anticipated sea ice losses will continue through the end of the 21st century. By contrast, Joint Plaintiffs claim that FWS failed to demonstrate that the polar bear is sufficiently likely to become endangered within the foreseeable future and, therefore, the agency wrongly concluded that the polar bear qualified for threatened status at the time of listing. In the alternative, a smaller subset of plaintiffs (including CBD, SCI, and CF) argues that FWS erred when it concluded that no polar bear population or ecoregion qualifies as a “distinct population segment,” which would have allowed the Sexwice to tailor ESA protections more narrowly across populations. Second, plaintiffs argue that FWS ignored or otherwise failed to adequately address four listing factors that the ESA requires the agency to consider. Joint Plaintiffs claim that the Service failed to adequately “take into account” foreign conservation programs, particularly Canadian sport-hunting programs, because it failed to ensure that its listing decision would not negatively impact those programs. Joint Plaintiffs also claim that the Service failed to demonstrate that it relied upon the “best available science,” because the climate models, population models, and population monitoring studies the Service relied upon do not, in fact, support the agency’s conclusion that the polar bear is likely to become endangered within the foreseeable future. Plaintiff CBD claims that FWS improperly downplayed the threat of hunting to the polar bear and wrongly concluded that the polar bear was not in danger of extinction at the time of listing as a result of the combined threats of habitat loss (“Listing Factor A”) and overutilization (“Listing Factor B”). Joint Plaintiffs finally claim that FWS wrongly concluded that existing regulatory mechanisms (“Listing Factor D”) will be insufficient to protect the polar bear despite future sea ice losses. Third and finally, plaintiffs identify deficiencies in the Service’s decision-making process for the Listing Rule. Plaintiff Alaska claims that FWS failed to provide an adequate “written justification” in response to the State’s comments, as it was required to do under Section 4(i) of the ESA. Plaintiff CF claims that FWS similarly erred by failing to respond to its comments on the Listing Rule. Having carefully considered each of these arguments, the Court is simply not persuaded that the Service’s decision to list the polar bear as a threatened species under the ESA was arbitrary and capricious. As the Supreme Court noted in Babbitt v. Sweet Home, “[t]he task of defining and listing endangered and threatened species requires an expertise and attention to detail that exceeds the normal province of Congress,” and of the courts as well. 515 U.S. 687, 708, 115 S.Ct. 2407, 132 L.Ed.2d 597 (1995). This Court is not empowered to substitute its own judgment for that of the agency but can only hold the agency to “minimal standards of rationality.” Ethyl Corp., 541 F.2d at 36. Accordingly, and for the reasons set forth below, the Court finds that the Listing Rule represents a reasoned exercise of the Service’s discretion based on the facts and the best available science at the time the agency made its determination. The Court will now address each of plaintiffs’ claims in turn. A. The Service Articulated a Rational Basis for Its Conclusion that the Polar Bear Met the Definition of a Threatened Species at the Time of Listing 1. Plaintiff CBD’s Claim that the Polar Bear Should Have Been Considered Endangered at the Time of Listing The Court turns first to plaintiff CBD’s claim that FWS wrongly concluded that the polar bear did not qualify for endangered status as of 2008. The Court will begin by outlining the Service’s interpretation of the definition of an endangered species under the ESA, as applied to the polar bear. a. The Service’s Findings In their original briefs and at a motions hearing held on October 20, 2010, the federal defendants argued that the text, structure, and legislative history of the ESA plainly and unambiguously require that a species must be in imminent danger of extinction to be designated as an endangered species. This Court held in a November 4, 2010 Memorandum Opinion that neither the statute itself nor its legislative history compels the federal defendants’ reading of the term “in danger of extinction” and that the term is, instead, ambiguous. In re Polar Bear, 748 F.Supp.2d at 28-29. Accordingly, following D.C. Circuit precedent, the Court remanded the rule to agency decision-makers to “fill in the gap” in the statute by providing additional explanation for the agency’s determination that the polar bear was not in danger of extinction at the time of listing. Id. at 29. On December 22, 2010, the federal defendants submitted the agency’s Supplemental Explanation in response to the Court’s remand order. The Service emphasizes that its Supplemental Explanation is not intended to set forth a new statement of agency policy or a new “rule” pursuant to the APA, nor does the agency intend to adopt independent, broad-based criteria for defining the statutory term “in danger of extinction.” Supp. Exp. at 1-2. Nonetheless, the agency claims that its starting point in making such a deteimination is the general understanding that the phrase “in danger of extinction” describes a species that is currently on the brink of extinction in the wild. Supp. Exp. at 3. According to FWS, to be “currently on the brink of extinction” does not necessarily mean that extinction is certain or inevitable; rather, whether a species is currently on the brink of extinction “depends on the life history and ecology of the species, the nature of the threats, and the species’ response to those threats.” Supp. Exp. at 3. As FWS describes, the agency’s past “endangered” listings can be broken out into roughly four categories: Category 1: Species facing a catastrophic threat from which the risk of extinction is imminent and certain. In this category, the timing of the threat alone is sufficient to deem the species in danger of extinction. The snail darter is the classic example of a species in this category. See Tenn. Valley Auth. v. Hill, 427 [437] U.S. 153 [98 S.Ct. 2279, 57 L.Ed.2d 117] (1978). This fish species was discovered shortly after the Tennessee Valley Authority had begun construction of the Tellico Dam on the Little Tennessee River and, at the time of listing, the dam project threatened to immediately and completely obliterate the only known population. Category 2: Narrowly restricted endemics that, as a result of their limited range or population size, are vulnerable to extinction from elevated threats. This category applies to species found in an extremely limited range that, in addition, are facing increasing threats. A large portion of listed species fall in this category. An example of one of these species is the Devil’s Hole pupfísh, which lives in a single sinkhole in the southern Nevada desert that is experiencing a drop in groundwater level. See Cappaert v. United States, 426 U.S. 128 [96 S.Ct. 2062, 48 L.Ed.2d 523] (1976). Category 3: Species formerly more widespread that have been reduced to critically low numbers or restricted ranges and, consequently, are at a high risk of extinction due to threats that would not otherwise imperil the species. This category represents a class of species experiencing both a severe range reduction and/or precipitous population crash combined with ongoing threats. Some examples of species falling in this category include California condors, whooping cranes, and vernal pool species, many of which have been all but wiped out by development and related factors. These species experience such a restricted range that they are extremely vulnerable to both ongoing and chance threats. Category 4: Species with relatively widespread distribution that have nevertheless suffered ongoing major reductions in numbers, range, or both, as a result of persistent threats. This category shares common characteristics with threatened species in that they have suffered some recent decline in numbers, range, or both, but to a more severe extent. An example of a species falling in this category is the red-cockaded woodpecker, which was formerly a common bird but experienced a precipitous decline in 1970 caused by an almost complete loss of its primary longleaf pine habitat. Currently, only small, isolated populations of this species remain, making the species more vulnerable to threats including reproductive isolation. Supp. Exp. at 4-6. Although there is no single metric for determining if a species is “in danger of extinction,” FWS contends that these four categories demonstrate the agency’s largely consistent approach to endangered species listings. See Supp. Exp. at'4. The Service asserts that its general understanding of the statutory definition of an “endangered species” and its approach to species listings .is supported by the text, structure, and the legislative history of the ESA. The Service notes that, insofar as an endangered species is any species which “is in danger of extinction” and a threatened species is any species which is “likely to become an endangered species within the- foreseeable future,” the ESA recognizes species with “two distinct degrees of imperilment based on the temporal proximity of the risk of extinction.” Supp. Exp. at 9. Within that general framework, the agency must exercise its discretion and expert judgment to weigh multiple factors on a species-specific basis. The Service asserts that its past listing decisions, including the polar bear Listing Rule, represent a reasoned exercise of that discretion, The Service contends that its species-specific listing determination for the polar bear constitutes a permissible construction of the ESA, given the life history and ecology of the species, the nature and timing of the threats, and the species’ observed and anticipated responses to those threats. According to FWS, the administrative record in this case demonstrates that, at the time of listing, the polar bear fit none of the four general categories of endangered species identified by the agency as representative of its past listing decisions. Rather, the evidence before the agency showed that at the time of listing the polar bear was a widespread, circumpolar species that had not been restricted to a critically small range or critically low numbers, nor had it suffered precipitous reductions in numbers or range. See Supp. Exp. at 15. Specifically, FWS found the following facts dispositive: • At the time of listing, the polar bear was widely distributed in nineteen populations and numbered in abundance between 20,000 to 25,000 individuals. Supp. Exp. at 15. • Fourteen of the nineteen polar bear populations were considered to be stable, increasing, or data deficient at the time of listing. Supp. Exp. at 15. • Only one population — Western Hudson Bay — was verified' to be in a statistically-significant decline, although two other populations were also actually or potentially declining. Supp. Exp. at 15. • No population decline was found to be precipitous, and reproduction and recruitment were still occurring in declining populations. Supp. Exp. at 15. In short, FWS determined, “there is simply no information in the Administrative Record to suggest that the species has experienced significant population declines or severe retractions in its range such that it is currently on the brink of extinction or that it faced a sudden and calamitous threat.” Supp. Exp. at 15-16. Accordingly, the agency concluded that the polar bear warranted listing as threatened range-wide but did not qualify as an endangered species at the time of listing, b. Plaintiff CBD’s Arguments Plaintiff CBD contends that, despite this Court’s remand order, the agency’s interpretation of the term “endangered species” to exclude the polar bear continues to violate the ESA. First, CBD contends that the agency has not significantly departed from its original position that an endangered species must be at risk of both imminent and certain extinction. According to CBD, nothing in the text, structure, or legislative history of the ESA supports the Service’s conclusion that the temporal proximity of an extinction threat is the controlling distinction between a threatened and an endangered species. Such a narrow reading of the statute, CBD contends, sets the bar for an “endangered” listing impossibly high. Moreover, it contravenes the purpose of the ESA, which is to provide a flexible approach to protecting species so that they can be recovered and delisted. CBD also claims that the Service unlawfully discounted or otherwise failed to consider key scientific information in determining that the polar bear was not endangered in any portion of its range. Indeed, CBD claims that FWS never actually analyzed whether, at the time of listing, polar bears fit within any of the four categories of endangered species described in its Supplemental Explanation. According to CBD, the administrative record demonstrates that the polar bear fits within three of the four “endangered” classifications identified by the agency. With respect to Category One, CBD asserts that FWS never considered whether global warming constitutes a “catastrophic threat.” CBD contends, as it did in its original briefing, that polar bears in at least the Seasonal and Divergent Ice Ecoregions face such a threat, and did at the time of listing, because the best available science at the time indicated that a certain amount of warming is already committed through the end of the 21st century and that continued warming trends are unlikely to be reversed in the near future. CBD points specifically to the USGS population modeling exercises, which projected declines in all of the polar bear ecoregions through mid-century, or approximately over a 45-year period. CBD also cites to evidence in the record, including the Listing Rule itself, which suggests that these models are only conservative estimates of the potential impacts to polar bears from sea ice losses. See ARL 117275 (“Simulated and projected rates of habitat loss during the late 20th and early 21st centuries by many [climate models] tend to be less than observed rates of loss during the past two decades; therefore, habitat losses based on [these models] were considered to be conservative.”); ARL 117280 (“The record low sea ice conditions of 2007 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.”). In addition to the USGS population monitoring exercises, CBD references population-specific studies to suggest that three populations — Western Hudson Bay, Southern Beaufort Sea, and Baffin Bay— were in danger of extinction at the time of listing. Reports in the record from the international Polar Bear Specialist Group indicate that six of the nineteen polar bear populations were declining at the time of listing, including these three. The Western Hudson Bay population saw a decline of twenty-two percent (22%) over an eighteen year period and showed statistically significant declines in body mass among female bears, ARL 117271, which must maintain a certain body weight to successfully reproduce, ARL 117270. Researchers estimated that cub production in this population would “probably be negligible within the next 15-25 years.” ARL 117270. Population numbers also declined in the Southern Beaufort Sea population, along with significant cumulative declines in observed cub survival and skull size and adult male body mass and skull size. See ARL 117272. Unprecedented instances of starvation and cannibalism among the Southern Beaufort Sea were also reported and attributed to nutritional stress. See ARL 117272. Finally, CBD points to a letter from the Marine Mammal Commission (“MMC”), the agency charged with advising FWS on marine mammal issues, which urged FWS to list the polar bear as endangered in light of the USGS population modeling reports. See ARL 126312. In its letter, MMC concluded that “[w]hen taken as a whole, [the USGS reports] present a bleak picture of the survival prospects of most populations of polar bears, absent rigorous management of the underlying factors driving climate change.” ARL 126315. According to CBD, this letter supports a conclusion that the agency acted arbitrarily in failing to find that the polar bear was endangered throughout a significant portion of its range at the time the agency made its decision. With respect to Category Two, CBD asserts that FWS never considered whether the polar bear should be considered a “narrowly restricted endemic” species facing elevated threats. By contrast, CBD contends that the polar bear should be considered an endemic species because it relies exclusively on a particular type of sea ice habitat. FWS acknowledged that this habitat type is at risk from continued warming patterns; indeed, this conclusion forms the basis for the agency’s decision to list the species as threatened. As such, CBD argues that the agency was obligated to consider whether the polar bear should have properly been classified as endangered because of its unique habitat needs and the particular threats to that habitat from climate change. Finally, with respect to Category Four, CBD asserts that the agency failed to consider whether any polar bear population “ ‘suffered ongoing major reductions in its numbers, range, or both, as a result of factors that have not been abated.’ ” CBD Supp. Mem. at 24 (quoting Supp. Exp. at 6). At the least, CBD contends that a twenty-two percent decline in the Western Hudson Bay population should have been considered a “major decline in numbers.” CBD Supp. Mem. at 24. CBD also points out that, although the polar bear was the first species to be listed due to climate change, FWS never considered whether the existence of a new threat might warrant the creation of an altogether new category. Instead, CBD contends, the agency relied on flawed conclusions, incorrect assumptions, and an unreasonably narrow interpretation of the statute to justify a lower level of protection for the polar bear than the species demands. According to CBD, the agency consistently failed to articulate a rational connection between the record evidence and the choice it made. For these reasons, CBD argues that the Service’s interpretation of the definition of “endangered species” to exclude the polar bear was arbitrary, capricious, and manifestly contrary to the text, structure, and purpose of the ESA. c. The Court’s Analysis As a threshold matter, the parties disagree on whether the Court is obliged to review the statutory interpretation set forth in the agency’s Supplemental Explanation under the deferential Chevron framework, or whether another standard should guide the Court’s review on remand. Before reaching the merits of the agency’s Supplemental Explanation, the Court must first determine the appropriate standard of review. The Court turns now to that question. i. Standard of Review on Remand As noted above, where a court reviews an agency’s interpretation of a statute it is charged with administering, such as the ESA, the Supreme Court’s opinion in Chevron, U.S.A., Inc. v. Natural Resources Defense Council, Inc. provides the appropriate framework of review. Here, the federal defendants, the defendant-intervenors, and the Joint Plaintiffs concur that this Court, having found that the agency’s plain-meaning interpretation of the definition of an endangered species fails under step one of the Chevron framework, should now analyze the agency’s Supplemental Explanation under step two of Chevron, which requires the Court to uphold any reasonable agency interpretation of ambiguous statutory language. See 467 U.S. at 843-4, 104 S.Ct. 2778. Plaintiff CBD contends, by contrast, that the agency’s Supplemental Explanation here is not “Chevron step two-worthy.” CBD Supp. Mem. at 4. Under the Supreme Court’s decision in United States v. Mead, an agency interpretation qualifies for Chevron review when it meets two requirements: (1) “when it appears that Congress delegated authority to the agency generally to make rules carrying the force of law,” and (2) “the agency interpretation claiming deference was promulgated in the exercise of that authority.” 533 U.S. at 226-27, 121 S.Ct. 2164; see also Pub. Citizen, Inc. v. HHS, 332 F.3d 654, 659 (D.C.Cir.2003) (citing Mead standard). According to CBD, the agency’s Supplemental Explanation meets neither of these requirements. Indeed, CBD goes further, arguing that the agency’s Supplemental Explanation is entitled to no deference at all. Where a Chevron analysis is inappropriate, the Supreme Court has held that an agency interpretation may nonetheless be entitled to “respect,” but only to the extent that interpretation has the “power to persuade.” Skidmore v. Swift & Co., 323 U.S. 134, 140, 65 S.Ct. 161, 89 L.Ed. 124 (1944); see also Power v. Barnhart, 292 F.3d 781, 786 (D.C.Cir.2002) (“Under Skidmore, we grant an agency’s interpretation only so much deference as its persuasiveness warrants.”). CBD asserts that the agency’s Supplemental Explanation has no “power to persuade” because it is inconsistent with the statute’s text, legislative history, and policy objectives, and because it is effectively post hoc rationalization, developed directly in response to litigation. Accordingly, CBD concludes, the agency’s interpretation of the statutory phrase “in danger of extinction” does not warrant deference under either the Chevron or the Skidmore standard, and this Court “must decide for itself the best interpretation of ‘in danger of extinction’ as applied to the polar bear.” CBD Supp. Mem. at 9 (citing Landmark Legal Found, v. IRS, 267 F.3d 1132, 1136 (D.C.Cir.2001)). After careful consideration of these arguments, the Court nevertheless concludes that Chevron provides the appropriate standard of review on remand. This Court remanded the Listing Rule to FWS for the very limited purpose of providing additional explanation for its listing determination for the polar bear. In other cases remanding an agency decision for a similarly limited purpose, the D.C. Circuit has subsequently reviewed the agency’s supplemental analysis under the Chevron framework. See Sec’y of Labor v. Nat’l Cement Co. of Cal., 573 F.3d 788, 793 (D.C.Cir.2009) (concluding that “the Secretary’s interpretation [on remand] is entitled to Chevron deference”); PDK Labs., Inc. v. DEA, 438 F.3d 1184, 1189-90 (D.C.Cir.2006) (“This leaves us with the task of resolving at Chevron’s second step whether the Deputy Administrator’s resolution of that ambiguity [on remand] is based on a permissible construction of the statute.”). Indeed, the D.C. Circuit recently addressed this precise question in Menkes v. U.S. Department of Homeland Security, 637 F.3d 319 (D.C.Cir.2011). In Menkes, as here, the D.C. Circuit remanded to the Coast Guard for a “forthright” agency interpretation of ambiguous statutory language in the Great Lakes Pilotage Act. Although the plaintiff in that case argued that the agency’s response on remand was not entitled to deferential Chevron review, the D.C. Circuit