The Paris Agreement Set an Unrealistic Target for Global Warming. Now What?

By Shannon Osaka. Originally published at Grist

It’s been a rallying cry for activists and a key talking point for diplomats. For decades now, 2 degrees Celsius (3.6 degrees Fahrenheit) of global warming has been viewed as a “do not cross” line in climate policy, a temperature at which cataclysmic and potentially permanent damage to the planet would take hold.

Countries that signed on to the 2015 Paris Agreement vowed to keep global warming “well below” 2 degrees Celsius of warming since the Industrial Revolution. National policies and international agreements are evaluated for how well they can help meet this target. There’s a general sense that if the world’s governments work fast enough and hard enough, we can still avoid the worst.

But what if that goal was not as realistic as many have assumed?

“In no way should 2 degrees — from a scientific perspective — be seen as a safe target,” said Peter Frumhoff, chief climate scientist at the Union of Concerned Scientists.

According to Frumhoff, 15 to 20 years ago climate scientists thought that 2 degrees of warming would avoid catastrophic climate change. “Our understanding of climate risks was that 2 degrees C would be a reasonably safe and achievable target.”

Over time, however, more updated research — most recently the special report by the UN’s Intergovernmental Panel on Climate Change — indicated that 1.5 degrees C is a safer, more scientifically robust, target. (Scary sidenote: We have already warmed by approximately 1 degree Celsius since pre-industrial times. Whoops.)

But even though activists and some governments have pushed for more stringent targets, 2 degrees has stuck. The Paris Agreement commits to “pursue efforts” to hold warming to 1.5 degrees, but 2 degrees has emerged as a kind of middle ground between countries feuding over climate change.

The problem is, neither goal is currently possible without the massive, massive deployment of technologies that don’t exist yet. Yes, we’ll have to improve renewable energy sources, like wind and solar, and build better batteries to store it all. But the possibility of reaching that 2-degree target by reducing emissions alone has shrunk to essentially zero.

At this point, it requires substantial investment into and development of so-called “negative emissions” technologies to suck carbon dioxide out of the atmosphere. Carbon dioxide emissions would need to reach net-zero by mid-century; which means we would need to start developing the technology, er, now.

We only have a limited amount of carbon left to burn, so little that even with extraordinarily steep reductions in energy use and a rapid scale-up of renewables, keeping warming to 2 degrees isn’t possible. Unless there were somehow a way to turn back the clock and undo some of what the largest emitters have done.

That’s where so-called negative emissions come in. In 2014, the UN Intergovernmental Panel on Climate Change released a new assessment on the state of the climate. This report included something surprising; scientists and modelers still thought 2 degrees was possible. But they had to introduce a new variable.

The 2014 report included something new — a “huge reliance on bioenergy with carbon capture and storage,” said David Victor, a professor of international relations at University of California San Diego.

Six years later, bioenergy with carbon capture and storage remains relatively untested (though there’s recent cause for optimism). It involves growing crops, burning them for fuel, capturing the subsequent emissions and storing them deep underground. As of last year, there are only five examples of the technology worldwide, none operating at a large scale. The most recent UN report says we would need a lot of it to hit the 2-degree target.

How much? Experts estimate it would take about 500 million hectares of land — an area 1.5 times the size of India.

“From a modeling point of view, the reason we see so much carbon capture and storage is because models see the existing energy system, and they see this incredible heroic goal,” Victor said. “So they move all the chips on the board into these deep reduction technologies: carbon capture and storage, bioenergy with carbon capture and storage … and they do all that because they can’t solve the equation. They literally can’t get there from here.”

Essentially, since reaching the 2-degree limit based on mitigation alone is impossible, modelerss have to assume that we will somehow remove emissions from the atmosphere later.

Some experts have criticized the use of negative emissions in modeling. According to Oliver Geden, head of the German Institute for International and Security Affairs, negative emissions technologies have mostly been used to mask failures of international action — the modeling form of kicking the can down the road. Negative emissions, Geden argues that it allow us to imagine that 2 degrees is possible, even as it becomes increasingly out of reach.

Victor agrees. “We need to grapple with the reality that we’re not going to meet the goals that we’ve talked about,” he said. The 2 degrees goal is probably out of reach; the flip side is, the worst-case climate scenario is probably not in the cards, either.

This doesn’t mean negative emissions shouldn’t be part of the picture. But experts say it does mean that policymakers and negotiators should be more transparent that the goal they have been working toward requires the adoption of technology at a scale that simply doesn’t exist yet.

Print Friendly, PDF & Email


  1. Isotope_C14

    “The 2 degrees goal is probably out of reach; the flip side is, the worst-case climate scenario is probably not in the cards, either.”

    -David Victor, a professor of international relations at University of California San Diego.

    Strangely, this here biologist can see that there was no snow cover in Southern Finland most of this year.

    The worst case climate sceneraio will directly impact every single one of us, and we are all currently frogs in a boiling pot.

    I wish these non-experts would really stop blathering. Every day that we spend trying to say “it won’t be that bad” is a day wasted where we could be converting cities and structures into giant carbon-capture/verticle agriculture configurations.

    1. SRH

      All such infrastructure changes require the expenditure of vast amounts of fossil fuels as well as great increases in the use of extraction. I have yet to see anyone who advocates such changes give any account of the cost to our carbon budget. I suspect it would blow it completely.

        1. Isotope_C14

          No worries SRH,

          Though, I’m not an advocate of high-impact fossil fuel driven conversion. I’m an advocate of de-growth, and mass reduction in transit. I’m fully aware that CO2 capture plants are not carbon neutral. We need to localize production just about everywhere, and a place like Las Vegas? That has to be just abandoned.

      1. J4Zonian

        Yes, such are the straits to which we’ve been driven by conservatives’ climate denying delayalism, economic and other lies, and anti-renewable fanaticism. We are not staying under 1.5°C over preindustrial temperature, and the chances of staying under 2° are essentially zero. 3° is looking extremely unlikely and the chances decrease every year we have Republicans or corporate Democrats in office in the US.

        Even though once progressives have enough power to act rationally, we can reduce energy use with efficiency, electrification, and wiser lives, we have no choice but to build our way out of the crisis with clean safe renewable energy, new farm infrastructure, ecological industry. Yup, that will all make it worse temporarily. Some effects will last a thousand years or more. Blame the right wing.

  2. Steve H.

    Caveat & whinging (first-person singular): Having been blanked out on the M*rcola rebuttal, and emails unanswered as to whether I overstepped on trying to get Yves’ post published, I’d stepped back while trying to determine if these were technical issues or personal. I am oversensitive, in ROC terms. However, I’ve been quoting Gregory Travis here for years, and the Boeing post has put a glint back in the kindling, so here goes. *EOL*

    At this point the problem isn’t CO2, it’s CH4. Land mass temperatures are already over 1.5’C increase, with the variance geographically located, the poles being more extreme. Methane releases are consistently popping at orders of magnitude higher than expected. Natalia Shakhova has given a 50% probability of a continental shelf burst which would raise global temperatures 0.6′ in two years. And the feedback loops appear to push 2′ to 3′ to 4′ to we’re all f*cked.

    Water has been buffering the issue for decades. When I got my MSES in ’93, ice melt modelling was done using surface area. Since then it was realized that volume is more relevant. And now they’ve found an enormous cavity in the Thwaites glacier. A lot more melt has happened than what the extrapolations indicated. And water is the magic substance, the best in the universe for buffering temperature change.

    Try this: you can use a pen to estimate regression. Pretend each point is a nail with a rubber band attached and put the pen in and let it stabilize. Understand the time frame for regression counts – preindustrial v from the 80’s v more recent. Bring up this chart:

    Look at the regression from 2010 (note the data points give higher-n than the averages). The high point is the El Nino of 2016. In the years after that we went from Cali hillsides burning while commuters went to work and the golfers played through; to the thousand-foot fire tornado; to AussiAussiAussi oy oy vey. And late 2020 looks like another El Nino.

    Four years from now is too late. What does that regression tell you in terms of time-frames? Global-GND horsepucky about batteries is just more crapitalism drowning us while we burn. The developing countries are planning on increasing CO2 expression by 120% in the next ten years. All the polisci game theory says that first to try loses (see Odum’s thermodynamic laws here). So not only do we need a leader to take us there, we need to challenge China’s coal and Russia’s pipelines directly. Who will be willing to put a missile on a Chinese coal plant, as Qiao Liang has written about?

    We’re self-deluded monkeys with a capacity for the divine. But here we are, at an existential point. If we fail, future discounting goes to zero and the costs are infinite for humanity. So, now what?

    1. Titus

      +10. Good facts and the passion is necessary. The article is pointless. Want to stop further (further) warming – simple ban all carbon fuels tomorrow. The constraint to that (as we that term in physics), the will to do it. All other approaches are suboptimal and with the same constraint. Time in this case is a measure of just how bad we want it to be. We seriously need to adopt new living arrangements with reality. The future is not going to resemble the past except with carbon-free™ Energy. The best we can hope for is life around 1823 with modern medicine and some electricity. But everything will be very local, and it will be a time of one emergency after another. I know because I model the sociological impacts of the unhinged climate. World wide we are at 1.3C°, I wish people would stop the nonsense. That’s an average, on land it’s higher to much higher at the poles it’s out of whack. At 2025 the world will be at 2C°. That year at least. 2063 is the new 2100 for the old climate models. Permant damage to the earth? That’s funny as that is impossible. The earth is. We ain’t on the other hand. The earth is nearly inhabitable. Yes or no. Only a yes is a yes everything is a no.

  3. pretzelattack

    i don’t know what’s going to happen, looks like it is going to be a bumpy ride in an airplane made by boeing. at this point, if i were betting on this as an alien in a galactic lottery, i would bet the earthlings will screw this up.

    1. False Solace

      It’s the Great Sieve, baby, the reason we can’t find any other complex life. Nobody survives this stage of development. Or nobody within the few million light years we can detect. Which is functionally the same.

      1. Math is Your Friend

        Not so.

        This isn’t really a place to dissect the Drake Equation, but there are other more likely reasons. Look at the underlying assumptions.

    2. Jeremy Grimm

      Phys.Org called attention to a recent paper discussing “Variations in precipitation at the North Pole set to increase sharply” []
      “Moreover, future changes in climate variability are less certain than changes in the average climate.” The research paper in Science Advances is open-access at “Strong future increases in Arctic precipitation variability linked to poleward moisture transport” []

      I believe these results may be regarded as preliminary. They are based on climate models. I tend to discount details of results from climate models because I suspect there are many important features of the climate which have not yet been modeled. I believe that is hinted at in the introduction to the Science paper: “This hinders the attribution of climate trends to specific forcings, especially in regions where climate variability is high, such as
      in the Arctic region.” I notice the Science paper also seems to keep its statements near the Arctic without extrapolating any implications for other regions.

      I think we are in for a rough ride.

      1. Titus

        Are you a scientist capable of doing peer review? Don’t beat on me, not all feedback to these articles and papers is of the same merit. Science isn’t a democracy. The problem at the poles is water vapor to unprecedented levels – that’s bad. Water vapor holds heat thus heating up the area, water, ice, and the land. This starts feedback loops in motion that make the problem worse, as in a run-away train worse. Can’t stop the feedback loops. As it’s all connected via the “butterfly” effect, here on earth, other feedback loops get going – like 17 months of non stop hurricanes, typhoons, or cyclones- call’em what you will. There’s a term we physicists use called ‘signaling’, its how we can see all these loops interacting. Generally there is a 2-3 year delay between say addition heat build up at the equator and its effect both in the poles and larger weather events like El Niño, which is the last thing the world needs right now. But sad to say…

        1. Jeremy Grimm

          You should write more carefully. I do not believe you really meant to ask: “Are you a scientist capable of doing peer review?” A scientist capable of doing a peer review is not necessarily capable of reviewing a paper in climate science. For example would like an organic chemistry professor to do the review? Some physicists might be competent to review a climate science paper but you should probably look for competent climate scientists capable of doing a peer review. Consider some of the consequences of demanding that only “competent climate scientists capable of doing a peer review” should read or draw inferences from a scientific paper in the field of climate science.

          I long ago gave up trusting solely to the opinions of experts in field ‘X’. I believe a reasonably well-educated citizen capable of critical thinking [I like to believe I am such a citizen] can and should draw their own conclusions. When I read a paper like the paper I referenced and read about moisture and precipitation at the arctic pole and their impacts on “variability” of what amounts to Arctic weather and notice what appears to be a careful effort to avoid any claims or speculations outside the very circumspect region of their research — I see that as a warning flag — there is more to this story. Other papers have been written linking shifts of the jet stream and other effects of Arctic weather to impacts on weather in other regions. Much of what I read about climate which is based on the climate models seems to suggest the transition to a new climate regime will be a nice linear process that shifts planting zones. I believe the weather patterns of the past year contradict that notion. I believe the paper I referenced gives further indications that the transition to a new climate regime will be a very bumpy road. Agriculture depends on relatively stable weather during a growing season — “the gentle rains will come” — they must or the corn will die.

          I very strongly believe that “Science isn’t a democracy.” I never claimed or suggested that it was. I am deeply troubled that climate scientists are forced to be so very circumspect in their claims because of the denialist attacks they must fend off supported by denialist ‘experts’ bought and paid for by Big Money. I believe the transition to a new climate will be very chaotic. I believe that notion is supported by the Paleoclimate papers I have read — mainly Hansen’s papers. I admit looking for and making an effort to infer evidence to support my belief from the paper I referenced. If the climate transitions of the Arctic could be more variable than originally modeled I do not think it is a stretch to infer that the climate transitions of regions even weakly coupled with the Arctic might also be more variable — although the referenced paper carefully avoids making any statements about that.

  4. Dwight

    It was well-known in the early 1990s that 1.0 degrees C was the “safe” target, and that 1.5 degrees C could set off a runaway greenhouse effect.

    1. Titus

      Models used that as a premise in 1980. The idea developed by oil company scientists was well known and accepted science since the early 1970s.

      1. Jeremy Grimm

        The idea of a ‘safe’ temperature increase is also tied to the push to come up with a ‘budget’ for how much more CO2 could be ‘safely’ added to the atmosphere. This notion, also developed and supported by the oil companies, moves climate to the economic realm while nicely avoiding unpleasant issues related to the existential impacts of a ‘little’ increase in the global temperature. Of course that little increase in temperature acquires considerable magnitude when converted to the amount of Heat energy added to the Earth’s climate systems.

  5. Peter

    The problem is, neither goal is currently possible without the massive, massive deployment of technologies that don’t exist yet. Yes, we’ll have to improve renewable energy sources, like wind and solar, and build better batteries to store it all.

    But the possibility of reaching that 2-degree target by reducing emissions alone has shrunk to essentially zero


    And then there is this:

    The phrase “clean energy” normally conjures up happy, innocent images of warm sunshine and fresh wind. But while sunshine and wind is obviously clean, the infrastructure we need to capture it is not. Far from it. The transition to renewables is going to require a dramatic increase in the extraction of metals and rare-earth minerals, with real ecological and social costs.
    We need a rapid transition to renewables, yes—but scientists warn that we can’t keep growing energy use at existing rates. No energy is innocent. The only truly clean energy is less energy……………………….In 2017, the World Bank released a little-noticed report that offered the first comprehensive look at this question. It models the increase in material extraction that would be required to build enough solar and wind utilities to produce an annual output of about 7 terawatts of electricity by 2050. That’s enough to power roughly half of the global economy. By doubling the World Bank figures, we can estimate what it will take to get all the way to zero emissions—and the results are staggering: 34 million metric tons of copper, 40 million tons of lead, 50 million tons of zinc, 162 million tons of aluminum, and no less than 4.8 billion tons of iron.”
    But they pointed out that unless consumption habits change, replacing the world’s projected fleet of 2 billion vehicles is going to require an explosive increase in mining: Global annual extraction of neodymium and dysprosium will go up by another 70 percent, annual extraction of copper will need to more than double, and cobalt will need to increase by a factor of almost four—all for the entire period from now to 2050.…/the-path-to-clean-energy…/

    Which means simply – we have to reduce by a large margin our use of energy, no matter how it will be produced, meaning a change in how much and what we produce, change from items produced solely to fulfill a created need that previously did not exist to the old ways to produce what we need to house, feed and work and stay somewhat healthy for a likely shorter lifespan.

    Everything else not directly connected to those primary needs will become unnecessary, superfluous and luxurious.
    The future will more resemble the past than the glossy expectations by some “futurist”.

    If the current trend of wealth disparity persists, we might even be going way back to a feudal society, neo feudal only in the sense that there might not be a king with central power, but a junta of the “haves”..

    1. False Solace

      It’s clear we can’t do these things on our planet. If we get really scifi, we can look at asteroid mining and extra-atmosphere solar collection. That’s the only way to get the metals we need and square km of collection we need without sacrificing entire continents or our entire high-energy civilization.

      Big problems? The amount of energy we’ll need to bootstrap enough infrastructure in space. Robotics aren’t nearly far enough advanced and won’t be. The fact the human body is really poorly suited to space and is going to break down up there, meaning a sacrifice of tens of thousands plus to agony and early death, and we have a really bad track record caring for laborers as a species. And finally, space-based solar collection looks tremendously easy to weaponize which doesn’t bode well given the known propensities of our elites. And of course, the current generation of elites has decided to hole up in NZ bunkers instead of even trying — they’ve already written us off. So basically, either The Expanse comes true (minus Mars, that’s a pipedream) or we’re f***d. So basically, we’re just f***d.

    2. Dwight

      It’s not even clear we have enough oil to build a new energy infrastructure using renewables and storage, not to mention the massive carbon emissions that would result. I haven’t calculated this and hope I’m wrong, but this seems like common sense to me. Can mining be done at scale without petroleum?

      1. xkeyscored

        Don’t forget the CO2 from all the concrete that would be involved in all this new infrastructure.

        1. Dwight

          Indeed. One windmill tower requires a massive concrete base. The trucks pouring the concrete need roads to get there. The sand in the concrete must be quarried, crushed, and transported. Now for the steel . . . And windmills don’t last forever. Dismantling and disposal requires big trucks.

      2. Peter

        “Can mining be done at scale without petroleum?”

        Of course it can. Like many futurists do: just posit we will find in the not too distant future a non carbon based energy source for extraction. Without any hint of a shadow of evidence and of course completely environmentally friendly enough that the waste is edible….That was easy, wasn’t it?

  6. Peter Dorman

    I’m not a carbon/energy modeler, and I haven’t gotten into the deep weeds on model methodology, but my sense from reading the literature is that mitigation pathway models generally fail to achieve 1.5º and often 2º stabilization because they can’t represent how an economy adjusts to an energy shortage and therefore are constrained not to have one. That is, they model substitution of renewables and efficiency for fossil fuels as policy prices (like carbon taxes), subsidies and regulatory interventions increase, and that generates the mitigation path. Carbon removal technologies are an add-on to allow these pathways to appear feasible and affordable.

    But the limitations of modeling are not the limitations of the world. Energy shortages *are* possible, and economies can respond to them through widespread recomposition at the micro level, replacing relatively energy-intensive activities with others that use less. More local cultural activities and classes, for instance, and less remote tourism. A shift to goods and services intensive in skill and less so for materials. I admit the transition is likely to be disruptive and difficult, but it can happen.

    We don’t have sufficiently fine-grained models of the economy, and even if we did they couldn’t be calibrated for conditions far outside past experience. But while models can be useful for policy, there are times when policy needs to go forward, models or not. This is one of them. We definitely can achieve 2º (450 ppm) stabilization through emissions reductions alone if we begin in the next few years to directly curtail them. (I fear 1.5º is out of reach unless additional measures that alter the carbon cycle prove fruitful.) It’s important to not give in to fatalism.

    As for carbon removal, definitely investigate and if warranted invest in it, but do this in addition to curtailing emissions, not as a substitute for it.

    1. Jeremy Grimm

      I believe your comment might also lead to contemplation of how the many instabilities designed into our Society, and its Economic and Political systems, might be impacted by disturbances due to Climate Chaos and resource depletion as the world population nears 8 billion souls. We live in a house built on a crumbling foundation with rotten pillars supporting rotten beams.

    2. fwe’zy

      Sure, we must shift to arts and leisure society, where consumption / enjoyment favor less fuel-intensive means. We are arguably engendering that right now with precarity and underemployment, for whoever survives the Great Culling. Before we prescribe frugal lives for the rest of the planet after we’ve already gorged, it’s critical to remember how much energy is currently lost to “friction” in the system, such as the inescapable overproduction built into capitalism. Removing planned obsolescence and other types of artificial waste from the equation leaves a lot more room for equitable distribution of comfort than doomsayers are describing.

      Let’s really talk about some class-related issues and disparities in material consumption. The ultra-wealthy private-jetters are the ones consuming at dangerous rates of excess, and their wealth depends on indoctrinating the masses into emulating them, to buy more of their crap. The political economic structures we live under demand a race to the bottom on all fronts except high-stakes hedonism, financed by others’ high-stakes deprivation and constant churn-n-burn. It’s not at all clear that the rest of the world has to go full frontal anprim: just them. :)

Comments are closed.