March & April 2024 climate extremes threaten doom

William P. Hall on May 12, 2024

If we don’t reverse the climate system’s growing energy imbalance it will soon drive us over the lethal fall into global mass extinction

ALL the global climate indicators are at or near all-time records so extreme that by September last year staid climate professionals have called the readings “gobsmackingly bananas.” — a phrase that is now in common usage in the climate science community. To some, the readings spell doom is nigh. But, here, i’m with the Guardian’s Fiona Katsaukas and her friend in the green shirt.

These gobsmacking records bear witness that Earth’s climate system has shifted into a new kind of rapidly evolving climate regime that is not encompassed or anticipated by existing climate forecasting models (at least not before 2050…). Every month since September has set new, still more extreme records.ALL the global climate indicators are at or near all-time records so extreme that by September last year staid climate professionals have called the readings “gobsmackingly bananas.” — a phrase that is now in common usage in the climate science community. These records bear witness that Earth’s climate system has shifted into a new kind of rapidly evolving climate regime that is not encompassed or anticipated by existing climate forecasting models (at least not before 2050…). Every month since September has set new, still more extreme records.

In 1985, the renowned planetary systems scientist and cosmologist (also one of the best communicators of hard science to the public the world has known), Karl Sagan addressed the U.S. Senate Environment and Public Works Subcommittee on Hazardous Wastes and Toxic Substances hearing on the greenhouse effect to explain the then scientific understanding of global warming. The 17 minute video on YouTube of his speech is extracted here by C-SPAN. C-SPAN also has the full 2 hour, 24 min video of the hearing. I mention this to triply underline the fact that the science of global warming and its consequences was already clearly understood four decades ago. The only fault in Sagan’s exposition is that the predicted dire consequences are happening sooner than he anticipated. This is still a common problem in climate science today where most climatologists trained in maths or physics still fail to appreciate the importance of fundamental non-linearity and chaos of complex dynamical systems like climate. The existential emergency Sagan predicted for the latter half of the 21st Century has already started now.

Because the [greenhouse] effects occupy more than a human generation there is a tendency to say that they are not our problem. Of course, then nobody’s problem, not on my tour of duty, not on my term of office… It’s something for the next century. Let the next century worry about it. But the problem is that the greenhouse effect is one of them which have long time constants. If you don’t worry about it now, it’s too late later on; and so in this issue, as in so many other issues, we are passing on extremely grave problems for our children when the time to solve the problems if they can be solved at all is now.

Carl Sagan, 1985, transcribed from C-SPAN video [2:30-3:15]

Today’s screams heard now from continually breaking climate records are the realities anticipated 39 years ago in this address;

In my “Feb. 2024 climate extremes” report (published March 12) I review the records as they were being broken in the February peak of the global climate cycle. I am currently trying to finish an update on the first anniversary of setting continuous daily record high global sea surface temperatures. detailing the piling up energy flows through the climate system (as described by Sagan) from the time solar energy is absorbed in the climate system and is eventually emitted back to space in the form of infrared emissions leaving the Earth. I have posted the current state of the first part, “Considering the first anniversary of a new climate regime — Accelerating down the road to extinction in Earth’s Hothouse Hell?” in the Google Docs format (that everyone should be able to read). Completing this is difficult because many indicators are literally breaking records faster than I can write about them. The most important of these regularly breaking records is the daily average sea surface temperature (SST), which is the first place excess solar energy piles up in the climate system. On 9 May SST is still more than 0.1 °C above 2023’s 9 May record – the 423 day of continuous daily records. The graph below focuses mainly on the part of the years where this year’s record is on top of last year’s. Note that Sagan also predicted rapidly rising sea levels. Today’s Washington Post describes how the southeastern US is currently being affected by this rise (probably because hot water is being backed up in the slowing Gulf Stream).

However, so people can see the evidence that is driving us here in @VoteClimateOne to do what we can to fight the emergency, I have also been posting to X-Twitter, and I include a couple of samples here:

As ever increasing numbers of climate scientists and aware commentators are crying out that it is time to sound the emergency alarms and urgently mobilize to fight the global emergency while there is still some chance that with our far greater knowledge and more powerful science than Sagan knew about (he suggested that by now it would be too late to stop the inevitable catastrophic end), it might still be possible for us reverse the solar energy imbalance that is rapidly driving our planet’s temperatures towards runaway feedbacks that will ensure global mass extinction is truly under way before the end of the 21st Century.

Another new fact in today’s in box hit me in the face. The record high rate of increase in CO₂ causing a majority the backup of the solar energy that is cooking us is still ACCELERATING UPWARDS at a record high RATE OF ACCELERATION. To me this suggests that runaway warming driven by positive feedbacks with temperature has well and truly started. ‘Natural’ emissions are already coming out of the ground, permafrost, wetlands, forests, and oceans faster than we are reducing fossil fuel emissions.

I’m like the girl in the green shirt in Katsaukas’s cartoon. I think it is well and truly time to sound all the emergency alarms and start total global mobilization to fight the crisis. My knowledge and experience tell me that if enough of us are willing to accept the reality of the danger and work together as a disciplined emergency force, we have sufficient knowledge and technological prowess to turn off the road to extinction and find some way to sustain at least some of the living world we know today.

Born in 1939, I’m old enough to remember living in a blacked out house in Los Angeles, and then the successful ending of WWII in 1945 little more than 4 years after America mobilized and joined the war at the end of 1941. At least in 1941-42 Americans managed the kind of mobilization we need today. I think we might still be able to defeat the runaway warming enemy if we start soon enough and fight hard enough to find a place in a still sustainable biosphere. On the other hand, I’m as close to certain that if continue to avoid looking at the grim and (for some) terrifying reality in hopes of continuing with business as usual, we will be burning up in the midst of the worst global mass extinction (i.e., even worse than the End Permian extinction ~ 250 million years ago).

As well as learning about global mass extinction when I learned to read from my father’s university textbooks in geology and paleontology, I grew up in navy towns started university as a pre-engineering student before changing my major to zoology and earning my PhD in evolutionary biology as well as teaching a variety of genetic, organismic, systems and population biology courses. I also worked professionally as a radiation ecologist and for the last 17 years before ‘retiring’ I designed a variety of documentation and knowledge management systems for Australia’s then largest defense engineering company. There, my systems helped ensure the on-time, on-budget completion of the ~7 billion $AU ANZAC Ship Project. (This is one of the very few large defense projects in world history that did not end up years overdue and billions of dollars of cost overruns, thanks in good part to systems I designed specifically to solve the kinds of management and engineering change issues that defeat most large defense projects). Finally in retirement I have spent some 15 years researching and writing on the coevolution of humans and our technologies prior to deciding that doing what I could to address the climate crisis was far more important than finishing a book for a society doing nothing to save itself from extinction.

In @VoteClimateOne.org we have thought a lot about what we can do to help the mobilization. It is clear that most governments in the world today are being run by fools, useful idiots, or puppets owned and led by already insanely rich fossil fuel and other special interests will do or say almost anything to gather more wealth. Political party discipline means that a majority government can be controlled by a handful of ‘strong’ party members and functionaries in leadership roles. For example, in Australia, the supposedly ‘climate friendly’ Labor majority government has just demonstrated its fealty to its puppet masters over effective climate action.

@VoteClimateOne.org has a two-pronged approach to try to change governments into supporters and even leaders of the climate emergency mobilization effort.

Given how urgent the need for action is, we hope to convince the puppets and other blockers that climate action is far more important and urgent than whatever benefits they gain from catering to the desires of their patrons and masters. However, this will take a massive effort – much more than just supplying truthful information that is easily ignored or actively denied. Minds might be changed if enough people piled on each and every recalcitrant parliamentarian – but this would take the concerted action of a large number of climate and environment action groups that has to this point not been forthcoming.

The other prong in the spear, is to actually replace enough of the recalcitrant parliamentarians with progressive community representatives or small party members who truly understand and accept the crisis and the need for action; and who are willing to put in the effort to get elected — to prevent either major party from forming a majority government. Not only will there be more sensible and effective parliamentarians, but any party forming government will have to listen to and compromise with genuine community representatives to do anything, even if this requires them to mobilize an effective climate action.

Our home page, ACT NOW, and TRAFFIC LIGHT VOTING explain how this all works, and provides examples of how we have addressed past elections. Hopefully all voters will have the chance to see and think about what these pages have to offer, and inform their voting decisions with the climate crisis in mind. As elections approach, CLIMATE SENTINEL NEWS will be providing frequent updates on the state of the climate and relevant political news.

Our grandchildren tell us all to “vote climate one” so they can have a happy future rather than the descent into Earth’s hothouse hell (like Sagan and most climate scientists until the last few months, the authors of the referenced paper have overestimated just how much time we have left for effective action).

WE MUST BEGIN ACTION NOW!

Views expressed in this post are those of its author(s), not necessarily all Vote Climate One members.

News in a year of no winter from midwinter in the northern USA

William P. Hall on March 1, 2024

If you want a future, it is time to take global warming seriously and totally mobilize to fight the fires driving us towards Hothouse Hell.

Bill McKibben, one of America’s most respected environmentalists and a founder of the international 350.org, reports from the northern state of Vermont on the winter that wasn’t. As noted by my featured image, even high school students in Pennsylvania have commented how extremely unwinterly their weather has been. These are signs of the rapidly accelerating global climate emergency.

From the article by Bill McKibben

As Winter Melts Away

Notes toward a eulogy for something I love

Bill McKibben, 29 Feb 2024 – The Crucial Years

I don’t write that often about developments in the actual climate in these pages—it’s uniformly depressing, and it is the part we can do the least about. None of us has the power to change how much heat a molecule of carbon dioxide traps, nor can we alter how the jet stream reacts to changes in polar temperatures. All we can do is determine how much CO₂ and methane there is up there in the air—and so that’s what I concentrate on.

And yet the changes underway on our planet are now so extreme, and so remarkable, that sometimes we do need to stand back and simply gaze in awe and sadness. At my latitude (43.97 degrees north, or very nearly halfway between the North Pole and the equator) the changes in winter may be the most dramatic signs yet. And the most dramatic in my heart for sure, because winter is the time I love the most.

This year in North America has been about as close as we’ve ever come to a year without a winter…. [T]he gases we produce increase the temperature: it was 70 degrees in Chicago yesterday, in February—which was also the day that the Windy City decided to join other American cities in suing the fossil fuel industry for damages. But that was just one of a hundred heat records broken in the course of the day, from Milwaukee to Dallas (94 degrees). But it wasn’t a single day of heat—it’s been an almost unrelentingly warm winter, with by far the lowest snow coverage for this time of year ever recorded (13.8 percent of the lower 48 as of Monday, compared with an average of more than 40 percent) and with the Great Lakes essentially free of ice.

…

In the high Arctic, previously unheard-of thunderstorms are melting ice faster than ever. As Ed Struzik reported last week from Greenland, “surface crevassing, which allows water to enter into the interior of the icecap, is accelerating, thanks to rapid melting. And slush avalanches, which mobilize large volumes of water-saturated snow, are becoming common: In 2016, a rain-on-snow event triggered 800 slush avalanches in West Greenland.”

Further south, those record winter temperatures let forests and grasslands dry out fast. That’s why Canada’s boreal forest burned at a record rate last summer, and it’s why huge blazes are driving Texans for cover today—the Smokehouse Creek fire in the Panhandle, which only started Monday, is already the second largest blaze in the state’s history; it forced the evacuation of the country’s biggest plant for disassembling nuclear weapons.

….

Read the complete article….

What does this mean?

I’m still trying to finish my February 2024 climate report on climate extremes as the indicators are growing faster than I can keep up with (Please see the working draft: Feb. 2024 climate extremes: Welcome to 2024 as we race down the road to Hothouse Earth). However, every day the meaning becomes more stark. Earth is heating up enough that large swathes of country are too warm for snowfall even in midwinter (amongst a vast array of other problems from extreme weather!).

Earth’s energy imbalance is currently increasing at an accelerating rate. Increasing concentrations of greenhouse gases (mainly CO2 and methane) trap an increasing amount of solar energy striking the planet. Earth can no longer radiate enough energy as long-wave infrared radiation to balance the books. Earth rises until the excess energy can be radiated away as shorter wavelength IR, and it won’t be able to cool down below the new balance until GHG concentrations fall enough so the necessary amount of energy can again be shed as longer wavelength IR.

Earth’s energy imbalance is currently increasing at an accelerating rate. Increasing concentrations of greenhouse gases (mainly CO2 and methane) trap an increasing amount of solar energy striking the planet. Earth can no longer radiate enough energy as long-wave infrared radiation to balance the books. Earth rises until the excess energy can be radiated away as shorter wavelength IR, and it won’t be able to cool down below the new balance until GHG concentrations fall enough so the necessary amount of energy can again be shed as longer wavelength IR.

Most of the excess energy is first absorbed in heating the oceans, and melting ice.

Rabid acceleration of Earth’s Energy Imbalance over the last 23 years. It is now ~4x as bad as it was at the beginning of the 21st Century. This will cause a comparable acceleration in rates of global warming (though perhaps with a few years of delay).
Global sea surface temperatures – every day since 1981. Temperatures have been above records for the day, every day of 2023 since since 15 March, and every day of 2024 so far (each of the thin black lines shows the variation in temperature for a year. Since my last version of this graph, on Feb 27, 2024 the temperature has risen to slightly above 21.1 °C. This is yet another new all-time record 2 weeks to 6 month’s before previous all-time records. (For details see my report for February 2024.)

Because of water‘s huge capacity for storing heat, more than 90% of solar energy goes first into heating the tropical and subtropical oceans. Currents circulate the heat around the planet, including its polar areas – even in midwinter. Warm water gradually melts polar ice from below and transfers heat energy into the atmosphere as ‘sensible heat‘ by increasing the air temperature and much more heat energy in the form of ‘latent heat‘ water vapor (= humidity). Particularly when water vapor condenses back into liquid (cloud droplets & precipitation), the atmospheric energy creates extreme weather and heats the land and melts a lot more ice from above. (Even if the ambient temperature is cold enough for the precipitated water to freeze as snow or hail, the region ends up being significantly warmer than if it hadn’t snowed!)

Decreasing snow and ice cover allows the Earth to absorb more solar energy in a positive feedback cycle to melt even more snow and ice. Warming soils, permafrost, and wetlands cause strong positive feedbacks by increasing greenhouse gas emissions to raise temperatures even faster…..

A couple of cartoons illustrate some of the difficulties in accepting the physical reality shown by this kind of evidence.

In other words, it is likely that Earth’s Climate System has already crossed several tipping points where exponentially growing positive feedbacks pushing us ever faster down the road of runaway global warming to Earth’s Hothouse Hell.

My guess is that pictures on the left are from last year’s movie, “Don’t Look Up” — where the mass extinction event was only a few days away.

Compared to a dinosaur killing meteorite strike in days, where runaway warming is concerned the final collapse will be decades to a couple of centuries away.

The problem is literally planetary in scale. Human greed, competition for power (both literally and figuratively), intelligence, and ingenuity led us to dig up and burn in little more than a century as much carbon as it Earth’s geological processes millions of years to sequester. We started this task with the aid of the original coal-burning steam-powered technology. And it is clear from the news I have been reporting on the Climate Sentinel that the emissions from the carbon we have already burned is probably enough to snuff out most complex life on Earth, including our own species.

However, if we take the threats of the climate catastrophe seriously and begin total emergency mobilization very soon, immediate action might actually minimize the collapse by reversing the global energy balance enough to allow some cooling to begin.

What to do about it?

With today’s vastly more sophisticated and powerful technology aided by our much greater understanding of science we should be able to work out how to recapture most of our carbon emissions and implement technology to put it back into the ground. However, this will require coordination at state, national, and global scales.

Unfortunately, most of our governments have been captured by special interests in the fossil fuel and ‘development’ industries who will have to immediately stop burning fossil fuels – and any effective action on their profits from emitting greenhouse gases is seen as a direct threat to their wealth. Thus they and their government stooges will do everything fair and foul to delay and deter actions to stop greenhouse emissions or broadly implement clean energy solutions. In the process they will invent very costly and thermodynamically impossible “carbon capture and storage” industries to sop up as much money as possible to keep it from being spent developing workable solutions. There isn’t much that we as individuals can do to solve these global scale problems.

Probably the most useful thing individuals can do is unite with others to change our governments by removing puppets and collaborators of the special interests from office, or convincing them that they will be replaced at the earliest opportunity if they don’t ditch their sugar daddy patrons and work for you and your community. You do this by electing people who are genuinely committed to working for their communities rather than special interest patrons (many of whom are not even citizens).

Vote Climate One was established to help you do this this, and our pages there offer a number of other suggestions as to how you may help change governments.

Views expressed in this post are those of its author(s), not necessarily all Vote Climate One members.

Updating IPCC AR6: still bound for catastrophe

William P. Hall on May 7, 2023

International group of climatologists launch a set of annually updated climate indicators to track human induced global warming through time.

This decade is absolutely critical for climate action if we are to avoid climate catastrophe. However, up to now we have lacked a standardized set of measures of the level of human-induced warming for tracking our progress over times as short as a year.

So far, the gold standard against which progress can be measured has been the IPCC’s cycle of Assessment Reports (e.g., the latest being AR6, completed this year). These have been published on cycle times of 6 to 7 years.

A team of 50 authors from major climate science institutes and universities around the world under lead author, Piers Maxwell Forster of the Priestly Centre University of Leeds, have set out to publish annually updated reliable global climate indicators in the public domain. This is based on the assessment methods used in the IPCC Sixth Assessment Report (AR6) Working Group One (WGI) report, to update the monitoring datasets and to produce updated estimates for key climate indicators. These include emissions, greenhouse gas concentrations, radiative forcing, surface temperature changes, the Earth’s energy imbalance, warming attributed to human activities, the remaining carbon budget and estimates of global temperature extremes. As these measurements are traceable and consistent with IPCC report methods, they can be trusted by all parties involved in UNFCCC negotiations and help convey wider understanding of the latest knowledge of the climate system and its direction of travel.

The preprint of their first update, Indicators of Global Climate Change 2022: Annual update of large-scale indicators of the state of the climate system and the human influence, was submitted for review (open for discussion on 05/05/2023) to the Copernicus journal Earth Systems Science Data.

Although still unreviewed, this work certainly provides the most up to date data on our progress towards reversing global warming while that might still be possible.

The news is bad. Although there are a few improvements in isolation, nothing we have done through the end of 2022 has been enough to perceptibly the rate of global warming.

Piers Maxwell Forster, et al. – 02/05/2023, Earth System Science Data

Indicators of Global Climate Change 2022: Annual update of largescale indicators of the state of the climate system and the human influence

Abstract. Intergovernmental Panel on Climate Change (IPCC) assessments are the trusted source of scientific evidence for climate negotiations taking place under the United Nations Framework Convention on Climate Change (UNFCCC), including the first global stocktake under the Paris Agreement that will conclude at COP28 in December 2023. Evidence-based decision making needs to be informed by up-to-date and timely information on key indicators of the state of the climate system and of the human influence on the global climate system. However, successive IPCC reports are published at intervals of 5–10 years, creating potential for an information gap between report cycles.

We base this update on the assessment methods used in the IPCC Sixth Assessment Report (AR6) Working Group One (WGI) report, updating the monitoring datasets and to produce updated estimates for key climate indicators including emissions, greenhouse gas concentrations, radiative forcing, surface temperature changes, the Earth’s energy imbalance, warming attributed to human activities, the remaining carbon budget and estimates of global temperature extremes. The purpose of this effort, grounded in an open data, open science approach, is to make annually updated reliable global climate indicators available in the public domain (https://doi.org/10.5281/zenodo.7883758, Smith et al., 2023). As they are traceable and consistent with IPCC report methods, they can be trusted by all parties involved in UNFCCC negotiations and help convey wider understanding of the latest knowledge of the climate system and its direction of travel.

The indicators show that human induced warming reached 1.14 [0.9 to 1.4] °C over the 2013–2022 period and 1.26 [1.0 to 1.6] °C in 2022. Human induced warming is increasing at an unprecedented rate of over 0.2 °C per decade. This high rate of warming is caused by a combination of greenhouse gas emissions being at an all-time high of 57 ± 5.6 GtCO2e over the last decade, as well as reductions in the strength of aerosol cooling. Despite this, there are signs that emission levels are starting to stabilise, and we can hope that a continued series of these annual updates might track a real-world change of direction for the climate over this critical decade.

Read the complete article….

Some of the observations:

The first set of observations shows that most human carbon emissions have not slowed, although, although the slowing economy over COVID have somewhat slowed overall growth (although this appears to have resumed in 2022). The only area where have actually significantly slowed emissions is for regulated fluorinated gases (F-gas).

Figure 1: Annual global anthropogenic greenhouse gas emissions by source, 1970-2021. Refer to Sect. 2.1 for a list of datasets. Starred datasets (*) indicate the sources used to compile global total greenhouse gas emissions in panel a. CO2 equivalent emissions in panels a and f are calculated using GWPs with a 100-year time horizon from the AR6 WGI Chapter 7 (Forster et al., 2021). F-gas emissions in panel a comprise only UNFCCC F-gas emissions (see Sect. 2.1 for a list of species). Not shown in panels d and e are biomass combustion emissions from GFED (Van Der Werf 2017), which are included in the aggregate estimate in panel a.

The next set of figures shows how effective the various gases in greenhouse layer in the atmosphere are at capturing solar radiation (i.e., “effective radiation forcing”). In 2a right facing bars represent a net positive forcing of higher temperatures, while the left facing bars represent the reflection of extra energy away from Earth. 2b shows a fairly abrupt increase in the forcing between 1960 and 1970, presumably due to the increasing annual rates of greenhouse gas emissions. Note: if the Earth is to have any chance to begin cooling the anthropogenic forcing (grey) needs to trend down, not to continue rising higher as it does here!

Figure 2: Effective radiative forcing from 1750-2022. (a) 1750-2022 change in ERF, showing best estimates (bars) and 5-95% uncertainty ranges (lines) from major anthropogenic components to ERF, total anthropogenic ERF, and solar 610 forcing.
Figure 2: Effective radiative forcing from 1750-2022.  (b) Time evolution of ERF from 1750 to 2022. Best estimates from major anthropogenic categories are shown along with solar and volcanic forcing (thin coloured lines), total (thin black line) and anthropogenic total (thick black line). 5-95% uncertainty in the anthropogenic forcing is shown in shaded grey. Note solar forcing in 2022 is a single-year estimate.

Because Earth currently suffers an imbalance between the solar energy it receives and what it radiates away to outer space as heat energy, the difference between energy received and energy radiated is stored as heat by raising the temperature of various components of planet’s mass (i.e., as the heat inventory). Figure 3a shows that the vast bulk is being stored at different water levels in the ocean, with virtually all of the remained represented by melted ice and the surface layer of soil. Again, if we are to even begin to reduce the rate of global warming, the graph of energy change must be changed to a down slope rather than the continuously rising one show here.

Figure 3b compares the IPCC’s estimates with the somewhat higher estimates presented in this paper.

Conclusion

There is absolutely no good news in the vast array of evidence assembled into these few graphs (assuming the work stands up to peer review, which it almost certainly will). Nothing humans have done to date has had a visible impact on the ominous trends into the climate crisis of the 6th global mass extinction in a ‘Hothouse Earth’ that will simply be too hot for many keystone species to survive physiologically. Beginning with Steffen et al’s, “Trajectories of the Earth System in the Anthropocene” and “Tripping down the road to Earth’s Hothouse Hell and Global Mass Extinction“, a series of articles in Climate Sentinel News explains that falling into the hothouse hell will be as easy as falling off a cliff.

As noted herein above, if we are to get off that road to Hell before it is too steep for that to be possible, we basically have to turn the graphs shown above upside down, so the trends are back towards where they were in the first half of the last century. We won’t be able to do this as long as our governments continue protecting and subsidizing the fossil fuel industries that are still making things worse from one year to the next. Basically our governments will have to work together and mobilize a global war against the climate emergency. Individually, as is the case in global war, we’ll probably have to accept rationing of critical or polluting resources and some curtailment of our usual freedoms to make things worse….

It will be hard, but consider this: It took us more about 100 years from beginning in 1927 with 2 bn people and steampunk technology to accidentally warm the planet to its present state. Starting now, with 2023’s highly advanced and incredibly more powerful technologies and scientific knowledge, we should be able cool the planet back to a sustainable temperature.

The first step has to be fixing our political systems so they work for all humans rather than working to make a few vested special interests become insanely wealthy and powerful individuals at the expense of the planetary biosphere.

Featured Image:

Summary from the Copernicus ESDD article bringing reported values from IPCC AR6 report up to date at the end of 2022. The causal chain from emissions to resulting warming of the climate system. Emissions of GHG have 1190 increased rapidly over recent decades (panel a). These emissions have led to increases in the atmospheric concentrations of several GHGs including the three major well-mixed GHGs (panel b). The global surface temperature (shown as annual anomalies from an 1850–1900 baseline) has increased by around 1.15°C since 1850–1900 (panel c). The human-induced warming estimate is a close match to the observed warming (panel d). Whiskers show 5% to 95% ranges. Figure is modified from AR6 SYR (Figure 2.1, Lee et al., 2023).

Views expressed in this post are those of its author(s), not necessarily all Vote Climate One members.