Since 2015, conservatives and legal experts have questioned the legality of the United States joining the Paris Agreement without Senate approval. Both President Obama and President Biden justified sidestepping the constitutional requirement by claiming the document was not a treaty and did not bind the U.S. to any “course of action.” However, a recent opinion by the International Court of Justice found that the agreement not only creates legal requirements, but also legal liability for countries that signed the treaty. This poses unique legal questions as to whether the U.S. ever legally joined the treaty and if the next Democrat President can rejoin it without Senate approval.
The Paris Agreement was adopted in 2015 to address the impacts of climate change. The agreement sets a goal of reaching net-zero GHG emissions by 2050. To reach that goal, a series of policies were adopted to address how governments and businesses reduce and report GHG emissions. It also focused on funding of both climate change initiatives and the economic impacts of climate change.
Within the U.S., the nature of the Paris Agreement has been debated. It has been a matter of dispute as to whether it is a treaty or an executive agreement. The differentiation is important.
Under the Constitution, the President “shall have Power, by and with the Advice and Consent of the Senate, to make Treaties, provided two thirds of the Senators present concur.” However, the President can enter into “executive agreements” that do not require approval of the Senate. While there are a lot of nuances to the difference, generally, a treaty is legally binding and could require the U.S. to change national law. Executive agreements are limited.
Even prior to adoption, President Obama asserted that the obligations of the agreement are aspirational, not legally binding. As a result, his administration believed it did not require Senate approval. This same rationale was used by President Biden when he rejoined the agreement after President Trump exited it. These arguments were echoed by Biden attorneys in a recent case before the International Court of Justice.
On March 29, 2023, at the request of Vanuatu, the United Nations General Assembly asked the ICJ to issue an advisory opinion on the legal obligations of countries in preventing climate change. The ICJ was established in 1945 through the UN Charter to handle legal disputes between nations. Known as the World Court, it is an outlet for countries to settle civil disputes through a neutral court.
The UNGA posed two questions to the ICJ:
“What are the obligations of States under international law to ensure the protection of the climate system and other parts of the environment from anthropogenic emissions of greenhouse gases for States and for present and future generations”?
“What are the legal consequences under these obligations for States where they, by their acts and omissions, have caused significant harm to the climate system and other parts of the environment, with respect to: (i) States, including, in particular, small island developing States, which due to their geographical circumstances and level of development, are injured or specially affected by or are particularly vulnerable to the adverse effects of climate change? (ii) Peoples and individuals of the present and future generations affected by the adverse effects of climate change?”
Developing countries asserted that the Paris Agreement created a legal liability for countries to meet the goal of net zero by 2050. They also argued that countries who contribute to climate change, through the production of fossil fuels and GHG emissions, should pay reparations to low lying and developing nations that are “adversely impacted” by climate change.
Much of the legal debate comes from the obligations states have under the Paris Agreement to submit reports to the UN. Article 4, paragraph 2 of the Agreement requires countries to “prepare, communicate and maintain successive nationally determined contributions that it intends to achieve. Parties shall pursue domestic mitigation measures, with the aim of achieving the objectives of such contributions.”
These NDCs outline actions taken by the the countries to reduce GHG emission. Throughout the legal proceedings, this process was referred to as procedural, meaning that countries are only required to go through the process of creating the report. The debate arose over whether there is a substantive, or actual action, required to enact the goals of the NDC. A substantive requirement creates a legal liability to act and could lead to legal consequences for failure to act.
In its oral statement before the Court in December, attorneys for the U.S. stated,
“…although the obligation of Parties under article 4.2 to ‘pursue’ domestic mitigation measures ‘with the aim of achieving the objectives of [their NDCs]’ is an important binding obligation of effort that must be performed in good faith, it provides Parties with a wide margin of appreciation with respect to what measures to pursue domestically, and by its terms does not require Parties to have in place a set of domestic measures that the Party assesses will achieve its NDC. Other provisions… complement the obligations described above by setting forth important non-binding expectations, but they do not establish legal obligations of Parties.”
The Court disagreed.
Following two years of proceedings, including both written and oral statements, the Court issued its Advisory Opinion relating to the Obligations of States in respect of Climate Change on July 23. The opinion created a new wave of liability for countries to address climate change, both within and beyond the confines of the Paris Agreement.
Looking specifically at the Paris Agreement, the Court found that the NDCs were legally binding.
“the Court considers that the discretion of parties in the preparation of their NDCs is limited. As such, in the exercise of their discretion, parties are obliged to exercise due diligence and ensure that their NDCs fulfill their obligations under the Paris Agreement and thus, when taken together, are capable of achieving the temperature goal of limiting global warming to 1.5°C above pre-industrial levels, as well as the overall objective of the ‘stabilization of greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic interference with the climate system’”
Importantly, the Court also found that the NDCs require countries to change their domestic policy to meet the goals of the Paris Agreement.
“The obligation that parties ‘shall pursue domestic mitigation measures’ is substantive in nature. The obligation is incumbent on ‘[p]arties’, which must be read as ‘all parties’, thus creating individual obligations for each party to the Agreement. Moreover, and as noted by most participants, the obligation to pursue domestic mitigation measures is an obligation of conduct and not an obligation of result.”
In other words, the ICJ believes the Paris Agreement creates legal obligations for countries to act and to change national law to align with those goals. The opinion, while not legally binding, creates a strong legal argument that the Paris Agreement required Senate approval.
For all sides of the debate, the ICJ opinion is a mixed bag. For climate change advocates, the establishment of a new legal liability for failing to take action to reduce the impacts of climate change is a huge win. How that will be applied to the U.S. is still unclear. For opponents of the Paris Agreement, the new legal argument that it is legally binding, and therefore would require Senate approval, could invalidate the previous ratifications and prevent the next Democrat President from rejoining the treaty. Ultimately, both issues will be decided in court.