The Senate Voted 95 to 0 Against a Climate Treaty Before Kyoto Was Written

Name one thing the United States Senate agreed on, unanimously, with only a handful of senators absent and no Democrat or Republican breaking ranks. It was not a tax cut. It was not a war. It was not even a resolution honouring a national holiday, which usually draws a stray objection. In July 1997 the Senate voted 95 to 0 against signing a climate treaty that did not yet exist.

That should make you sit up. Ninety-five senators, from both parties, from coal states and coastal states, from the most liberal to the most conservative, said the same thing months before the Kyoto Protocol was adopted. And then the executive branch went right ahead and negotiated what the Senate had just warned it not to negotiate. If you want to understand why American climate policy has been a mess ever since, start there.

The Resolution

The measure was Senate Resolution 98, introduced by Senator Robert Byrd of West Virginia, a Democrat, and Senator Chuck Hagel of Nebraska, a Republican. That is why it is called the Byrd-Hagel Resolution. The Senate passed it on July 25, 1997, by a vote of 95 to 0.

A Senate resolution of this kind is not a law. It does not bind the President, and it does not amend anything. It is a statement of the Senate's view about what it would be willing to approve, and under the Constitution the Senate's view on treaties is the one that counts. I will come back to why.

What did the resolution actually say? In plain terms, it said that the United States should not sign any international agreement on greenhouse gases that did either of two things. First, an agreement that required new emission limits from the wealthy, industrialized nations while leaving the developing nations with no new commitments in the same period. Second, an agreement that would seriously harm the American economy. The Senate also asked that any such treaty come with a detailed analysis of what it would cost and how it would be carried out.

Read that again, because people misdescribe it. The Senate did not say that the climate was not changing. It did not say that America should do nothing. It set two conditions: do not exempt the fastest-growing emitters, and do not wreck our economy. A resolution that would have been unremarkable common sense in any other negotiation was treated as heresy by the people running this one.

Why the Senate Said It

To see why the vote was unanimous, you have to remember the structure of the deal being negotiated. In 1992 the United States had ratified the United Nations Framework Convention on Climate Change, which was a broad framework with no binding limits. The follow-up negotiation, under what was called the Berlin Mandate, aimed at binding targets, but only for the developed countries. Developing nations, including the two most populous countries on earth and some of the fastest-growing economies, would face no numerical limits at all.

Think about the logic of that. A treaty about a global atmosphere that bound a minority of the world's emitters, and left the majority free to grow without restriction, would shift manufacturing and emissions abroad without necessarily cutting the world's total. Industry would move to wherever the rules were looser, and the planet would get the same carbon and America would get the unemployment. A senator did not need to doubt the science to see the design flaw. He only needed to read the treaty's scope.

That is the point I want you to hold on to. The 95 to 0 vote was not a vote against the environment. It was a vote against a bad bargain. And a rule that applies to you but not to your competitors, and that does not reduce the thing it claims to reduce, is not a rule worth signing.

Kyoto: Signed, Never Submitted

In December 1997 the negotiators in Kyoto, Japan finished the protocol. It set binding emission targets for the developed countries and, as feared, left the developing world without them. The Senate's conditions had been disregarded.

The Clinton administration signed the protocol on November 12, 1998. And then it did something that tells you all you need to know. It never sent the treaty to the Senate for ratification. The Senate had already said, 95 to 0, what conditions it wanted, and the protocol did not meet them. A treaty that does not meet the conditions the Senate set had little chance of winning two thirds.

In 2001 the Bush administration announced that it would not support the protocol, and the United States never ratified it. The protocol entered into force in 2005 without us. That is the whole Kyoto story from the American side: a treaty signed for the cameras and never ratified, because the one body with the power to ratify had said in advance it would not.

The Constitutional Point

Now to the clause that makes all of this matter. Article II, Section 2, Clause 2 of the Constitution says of the President:

He shall have Power, by and with the Advice and Consent of the Senate, to make Treaties, provided two thirds of the Senators present concur.

Take that sentence apart. The President negotiates. But the power to make a treaty belongs to the President acting with the advice and consent of the Senate, and it takes two thirds of the senators present. The Framers set the bar high on purpose. A treaty, once ratified, becomes part of what Article VI calls "the supreme Law of the Land." That is a great deal of power to give to anyone, and they wanted it to rest on a broad consensus rather than a bare majority.

Alexander Hamilton explained the reasoning in Federalist No. 75, arguing that the executive alone could not be trusted with the treaty power but that the Senate's participation would provide a check. John Jay, in Federalist No. 64, made the case that the Senate's involvement would attract wise and experienced judgment. The details differ, but the design is clear: foreign agreements that bind the nation are a joint product of the executive and the Senate, not a gift from one to the other.

And look at the arithmetic in 1997. Two thirds of a full Senate is 67 votes. The resolution got 95. A treaty that the Senate had just said it would not accept on those terms was never going to find 67 votes. That was the point of the exercise: to tell the President in advance what the constitutional price of a deal would be.

The Workaround

So what does an administration do when it wants a climate deal and knows it cannot win two thirds of the Senate? It stops calling it a treaty.

The Paris Agreement, adopted in December 2015, is the example. The agreement was never submitted to the Senate. The Obama administration took the position that it was not a treaty requiring Senate consent, partly because its central emission pledges were framed as nationally determined contributions rather than legally binding targets, and the President joined it on his own authority in September 2016. Supporters called this a clever solution. Critics called it a way around Article II. Both descriptions are accurate, and which one you prefer depends on whether you believe the Treaty Clause means what it says.

I think it means what it says. I will offer a test. If a president can commit the nation to a major long-term international program, one he describes as essential to the fate of the planet, without a single Senate vote, then what exactly is the Treaty Clause for? If the answer is that it applies only when the President chooses to use it, then it is not a check. It is a suggestion.

Here is the fair response, and I want to state it at its strongest. Presidents have made agreements with other countries without Senate approval for a very long time. Some of these are congressional-executive agreements, approved by a majority of both houses, and some are agreements made solely on the President's own authority within his constitutional powers. Courts have not generally policed the line between a treaty and an executive agreement. Paris, the argument goes, asked for pledges rather than binding legal limits, so it falls on the executive side of the line.

Here is the answer in order.

1. A pledge is a commitment. The agreement's own structure was a commitment to submit national plans, report progress and ratchet up ambition over time. The administration used it as leverage both abroad and at home, and domestic regulation was justified in part by what the nation had promised.
2. The nation was asked to live by it. Whatever the formal label, it shaped energy rules for millions of Americans. A measure with effects like a treaty should pass through the process designed for treaties.
3. The Senate's own position was known. Byrd-Hagel was a standing warning. Evading a unanimous Senate position through relabelling is exactly what a separation of powers is meant to prevent.
4. Reversibility proves the problem. The agreement was joined by one president, and in June 2017 another announced the withdrawal. The withdrawal took effect in November 2020, and a third President rejoined in January 2021, effective the following month. In January 2025 the current administration ordered withdrawal again. A commitment that flips every time the White House changes hands is not a national commitment at all, which is exactly why Article II requires the Senate's two-thirds.

That fourth point is the one I would underline. The Framers built the Treaty Clause so that our word would be reliable. A foreign government deciding whether to trust an American promise wants to know it will outlast the next election. A treaty ratified by two thirds of the Senate does. A presidential pledge does not, and the last decade has shown it.

What the Vote Says About Climate Politics

There is a lesson here that goes beyond the clause. The reason the executive branch avoids the Senate is that it cannot win. If a climate agreement would be good for America and acceptable to the voters, it should be able to attract sixty-seven senators. The fact that it cannot is information. It tells you that the terms, whether the exemption of the largest emitters or the cost to the economy, are not terms that the country's elected representatives will accept in the light of day.

I am not asking anyone to ignore climate. I am asking that policy be made the way the Constitution makes it. If the case is strong, make it to the Senate and win. If it is weak, the weakness is the point. For more on how to weigh a climate measure by what it buys, see Grant the Warming, Then Ask What Each Climate Policy Actually Buys. For the history of how the federal government has tried to price energy by decree, see The Wind Tax Credit Was Temporary in 1992 and Kept Coming Back for Decades. And for how many people on earth still lack the basics of modern energy, which developing nations do not want to be denied, see Hundreds of Millions Still Cook Over Wood, and That Is a Moral Question.

The Developing-World Objection, Answered

The strongest objection to the Byrd-Hagel position is one of fairness: the wealthy countries emitted most of the carbon over the last two centuries, so they should cut first and fastest. The treaties built that principle in, calling it common but differentiated responsibilities.

I take that argument seriously and I will answer it plainly. First, the allocation of historical blame does not change the physics of the atmosphere. If the goal is to lower the world's total emissions, then a treaty that exempts the fastest-growing sources fails on its own terms, however fair it sounds in a seminar. Second, billions of people in poorer countries want electricity, refrigeration and heat, and they are entitled to want them. The right answer is cheap, reliable energy for them, including gas, nuclear and hydro, not a plan that treats poverty as a carbon budget. Third, a treaty that puts the burden on a single country's workers while the biggest competitors build coal plants on schedule is not climate policy. It is industrial policy for someone else.

It is entirely possible to believe that the climate is warming, that humans contribute, and that this particular treaty design was a mistake. The Senate vote proves it. Ninety-five senators believed exactly that.

The Treaty Clause Is a Citizen's Tool

One last point, the one a citizen can use. Under the Constitution, the person with the power to say no to a treaty is the senator you vote for. That means you have more leverage over the next international agreement than you think. A senator who hears from the home state before a vote, on the record, in writing, knows what the voters expect. A treaty that cannot survive a hearing and a roll call should not bind the country.

This is the same principle that governs everything else. Power that is spread across institutions, and tied to votes, is power the people can hold to account. Power that is exercised by pledge and press release is power nobody can easily check. The Founders knew the difference, and the 95 to 0 vote shows that, once, the Senate knew it too.

The Case in Brief

1. On July 25, 1997 the Senate passed the Byrd-Hagel Resolution 95 to 0, warning against any climate treaty that exempted developing nations from new commitments or seriously harmed the American economy.
2. The Kyoto Protocol, adopted that December, ignored both conditions, and the United States signed it in 1998 but never submitted it to the Senate for ratification.
3. Article II, Section 2 requires the advice and consent of two thirds of the Senators present for a treaty, because the Framers wanted lasting agreements built on broad consensus.
4. The Paris Agreement of 2015 was handled as an executive agreement, and its repeated withdrawals and re-entries show why a commitment without Senate approval cannot be relied upon.
5. A climate deal worth having should be able to win sixty-seven senators, and the inability to do so is evidence about the terms.

What you can do: Read Article II, Section 2 of the Constitution at the Constitution page, then write to your senators asking them to commit publicly to requiring a Senate vote on any international climate agreement.