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Shortly after the Navy released its EA, the plaintiffs sued the Navy, seeking declaratory and injunctive relief on the grounds that the Navy’s SOCAL training exercises violated NEPA, the Endangered Species Act of 1973 (ESA), and the Coastal Zone Management Act of 1972 (CZMA).2 The District Court granted plaintiffs’ motion for a preliminary injunction and prohibited the Navy from using MFA sonar during its remaining training exercises. The court held that plaintiffs had “demonstrated a probability of success” on their claims under NEPA and the CZMA. Pet. App. 207a, 215a. The court also determined that equitable relief was appropriate because, under Ninth Circuit precedent, plaintiffs had established at least a “‘possibility’” of irreparable harm to the environment. Id., at 217a. Based on scientific studies, declarations from experts, and other evidence in the record, the District Court concluded that there was in fact a “near certainty” of irreparable injury to the environment, and that this injury outweighed any possible harm to the Navy. Id., at 217a–218a.

The Navy filed an emergency appeal, and the Ninth Circuit stayed the injunction pending appeal. 502 F. 3d 859, 865 (2007). After hearing oral argument, the Court of Appeals agreed with the District Court that preliminary injunctive relief was appropriate. The appellate court concluded, however, that a blanket injunction prohibiting the Navy from using MFA sonar in SOCAL was overbroad, and remanded the case to the District Court “to narrow its injunction so as to provide mitigation conditions under which the Navy may conduct its training exercises.” 508 F. 3d 885, 887 (2007).
On remand, the District Court entered a new preliminary injunction allowing the Navy to use MFA sonar only as long as it implemented the following mitigation measures (in addition to the measures the Navy had adopted pursuant to its MMPA exemption): (1) imposing a 12-mile “exclusion zone” from the coastline; (2) using lookouts to conduct additional monitoring for marine mammals; (3)restricting the use of “helicopter-dipping” sonar; (4) limiting the use of MFA sonar in geographic “choke points”; (5) shutting down MFA sonar when a marine mammal is spotted within 2,200 yards of a vessel; and (6) powering down MFA sonar by 6 dB during significant surface ducting conditions, in which sound travels further than it otherwise would due to temperature differences in adjacent layers of water. 530 F. Supp. 2d 1110, 1118–1121 (CD Cal. 2008). The Navy filed a notice of appeal, challenging only the last two restrictions.
The Navy then sought relief from the Executive Branch. The President, pursuant to 16 U. S. C. §1456(c)(1)(B),granted the Navy an exemption from the CZMA. Section 1456(c)(1)(B) permits such exemptions if the activity in question is “in the paramount interest of the United States.” The President determined that continuation of the exercises as limited by the Navy was “essential to national security.” Pet. App. 232a. He concluded that compliance with the District Court’s injunction would “undermine the Navy’s ability to conduct realistic training exercises that are necessary to ensure the combat effectiveness of . . . strike groups.” Ibid.
Simultaneously, the Council on Environmental Quality (CEQ) authorized the Navy to implement “alternative arrangements” to NEPA compliance in light of “emergency circumstances.” See 40 CFR §1506.11.3 The CEQ deter-mined that alternative arrangements were appropriate because the District Court’s injunction “create[s] a significant and unreasonable risk that Strike Groups will not be able to train and be certified as fully mission capable.” Pet. App. 238a. Under the alternative arrangements, the Navy would be permitted to conduct its training exercises under the mitigation procedures adopted in con- junction with the exemption from the MMPA. The CEQ also imposed additional notice, research, and reporting requirements.
In light of these actions, the Navy then moved to vacate the District Court’s injunction with respect to the 2,200-yard shutdown zone and the restrictions on training in surface ducting conditions. The District Court refused to do so, 527 F. Supp. 2d 1216 (2008), and the Court of Appeals affirmed.

The Ninth Circuit held that there was a serious question regarding whether the CEQ’s interpretation of the “emergency circumstances” regulation was lawful. Specifically, the court questioned whether there was a true “emergency” in this case, given that the Navy has been on notice of its obligation to comply with NEPA from the moment it first planned the SOCAL training exercises. 518 F. 3d, at 681. The Court of Appeals concluded that the preliminary injunction was entirely predictable in light of the parties’ litigation history. Ibid. The court also held that plaintiffs had established a likelihood of success on their claim that the Navy was required to prepare a full EIS for the SOCAL training exercises. Id., at 693. The Ninth Circuit agreed with the District Court’s holding that the Navy’s EA—which resulted in a finding of no significant environmental impact—was “cursory, unsupported by cited evidence, or unconvincing.” Ibid.4

The Court of Appeals further determined that plaintiffs had carried their burden of establishing a “possibility” of irreparable injury. Even under the Navy’s own figures, the court concluded, the training exercises would cause 564 physical injuries to marine mammals, as well as170,000 disturbances of marine mammals’ behavior. Id., at 696. Lastly, the Court of Appeals held that the balance of hardships and consideration of the public interest weighed in favor of the plaintiffs. The court emphasized that the negative impact on the Navy’s training exercises was “speculative,” since the Navy has never before operated under the procedures required by the District Court.
Id., at 698–699. In particular, the court determined that:

(1) the 2,200-yard shutdown zone imposed by the District Court was unlikely to affect the Navy’s operations, be-cause the Navy often shuts down its MFA sonar systems during the course of training exercises; and (2) the power-down requirement during significant surface ducting conditions was not unreasonable because such conditions are rare, and the Navy has previously certified strike groups that had not trained under such conditions. Id., at 699–702. The Ninth Circuit concluded that the District Court’s preliminary injunction struck a proper balance between the competing interests at stake.
We granted certiorari, 554 U. S. __ (2008), and now reverse and vacate the injunction.

III

A

A plaintiff seeking a preliminary injunction must establish that he is likely to succeed on the merits, that he is likely to suffer irreparable harm in the absence of preliminary relief, that the balance of equities tips in his favor, and that an injunction is in the public interest. See Munaf v. Geren, 553 U. S. __, __ (2008) (slip op., at 12); Amoco Production Co. v. Gambell, 480 U. S. 531, 542 (1987); Weinberger v. Romero-Barcelo, 456 U. S. 305, 311–312 (1982).
The District Court and the Ninth Circuit concluded that plaintiffs have shown a likelihood of success on the merits of their NEPA claim. The Navy strongly disputes this determination, arguing that plaintiffs’ likelihood of success is low because the CEQ reasonably concluded that “emergency circumstances” justified alternative arrangements to NEPA compliance. 40 CFR §1506.11. Plaintiffs’ briefs before this Court barely discuss the ground relied upon by the lower courts—that the plain meaning of “emergency circumstances” does not encompass a court order that was “entirely predictable” in light of the parties’ litigation history. 518 F. 3d, at 681. Instead, plaintiffs contend that the CEQ’s actions violated the separation of powers by re adjudicating a factual issue already decided by an Article III court. Moreover, they assert that the CEQ’s interpretations of NEPA are not entitled to deference because the CEQ has not been given statutory authority to conduct adjudications.
The District Court and the Ninth Circuit also held that when a plaintiff demonstrates a strong likelihood of prevailing on the merits, a preliminary injunction may be entered based only on a “possibility” of irreparable harm. Id., at 696–697; 530 F. Supp. 2d, at 1118 (quoting Faith Center Church Evangelistic Ministries v. Glover, 480 F. 3d 891, 906 (CA9 2007); Earth Island Inst. v. United States Forest Serv., 442 F. 3d 1147, 1159 (CA9 2006)). The lower courts held that plaintiffs had met this standard because the scientific studies, declarations, and other evidence in the record established to “a near certainty” that the Navy’ straining exercises would cause irreparable harm to the environment. 530 F. Supp. 2d, at 1118.

The Navy challenges these holdings, arguing that plain-tiffs must demonstrate a likelihood of irreparable injury—not just a possibility—in order to obtain preliminary relief. On the facts of this case, the Navy contends that plaintiffs’ alleged injuries are too speculative to give rise to irreparable injury, given that ever since the Navy’s training pro-gram began 40 years ago, there has been no documented case of sonar-related injury to marine mammals in SOCAL. And even if MFA sonar does cause a limited number of injuries to individual marine mammals, the Navy asserts that plaintiffs have failed to offer evidence of species-level harm that would adversely affect their scientific, recreational, and ecological interests. For their part, plaintiffs assert that they would prevail under any formulation of the irreparable injury standard, because the District Court found that they had established a “near certainty” of irreparable harm. We agree with the Navy that the Ninth Circuit’s “possibility” standard is too lenient. Our frequently reiterated standard requires plaintiffs seeking preliminary relief to demonstrate that irreparable injury is likely in the absence of an injunction. Los Angeles v. Lyons, 461 U. S. 95, 103 (1983); Granny Goose Foods, Inc. v. Teamsters,
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