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Explaining climate change science & rebutting global warming misinformation

Global warming is real and human-caused. It is leading to large-scale climate change. Under the guise of climate "skepticism", the public is bombarded with misinformation that casts doubt on the reality of human-caused global warming. This website gets skeptical about global warming "skepticism".

Our mission is simple: debunk climate misinformation by presenting peer-reviewed science and explaining the techniques of science denial, discourses of climate delay, and climate solutions denial.


Skeptical Science New Research for Week #8 2024

Posted on 22 February 2024 by Doug Bostrom, Marc Kodack

Open access notables

Transition from positive to negative indirect CO2 effects on the vegetation carbon uptake, Chen et al., Nature Communications:

Here we investigate how the impacts of eCO2-driven climate change on growing-season gross primary production have changed globally during 1982–2014, using satellite observations and Earth system models, and evaluate their evolution until the year 2100. We show that the initial positive effect of eCO2-induced climate change on vegetation carbon uptake has declined recently, shifting to negative in the early 21st century. Such emerging pattern appears prominent in high latitudes and occurs in combination with a decrease of direct CO2 physiological effect, ultimately resulting in a sharp reduction of the current growth benefits induced by climate warming and CO2 fertilization. Such weakening of the indirect CO2 effect can be partially attributed to the widespread land drying, and it is expected to be further exacerbated under global warming.

Real-world time-travel experiment shows ecosystem collapse due to anthropogenic climate change, Li et al., Nature Communications

Predicting climate impacts is challenging and has to date relied on indirect methods, notably modeling. Here we examine coastal ecosystem change during 13 years of unusually rapid, albeit likely temporary, sea-level rise ( > 10 mm yr−1) in the Gulf of Mexico. Such rates, which may become a persistent feature in the future due to anthropogenic climate change, drove rising water levels of similar magnitude in Louisiana’s coastal wetlands. Measurements of surface-elevation change at 253 monitoring sites show that 87% of these sites are unable to keep up with rising water levels. We find no evidence for enhanced wetland elevation gain through ecogeomorphic feedbacks, where more frequent inundation would lead to enhanced biomass accumulation that could counterbalance rising water levels. We attribute this to the exceptionally rapid sea-level rise during this time period. Under the current climate trajectory (SSP2-4.5), drowning of ~75% of Louisiana’s coastal wetlands is a plausible outcome by 2070.

The importance of crowdsourced observations for urban climate services, Mitchell & Fry, International Journal of Climatology:

Crowdsourced observation networks are typically much more dense than those maintained by National Meteorological Services, and sample a much wider range of local climates. This offers an opportunity to build observed climatologies that are more representative of lived experience, particularly in cities. This study provides a worked example to show their potential for improving operational climate services, and to identify the challenges to realizing that potential. To demonstrate the concept, data from personal weather stations, obtained through citizen science, are used to build an observed record of daily maximum temperatures in 2020 in Manchester (UK). This record is compared to the standard baseline used in a current climate service, showing a substantial increase in the estimated heat hazard. If such potential benefits are to be realized in a climate service, it will be necessary to first build an alternative observed baseline of decadal length and at national or international scale. 

Widespread and increasing near-bottom hypoxia in the coastal ocean off the United States Pacific Northwest, Barth et al., Scientific Reports:

During summer 2021, an unprecedented number of ship- and underwater glider-based measurements of dissolved oxygen were made in this region. Near-bottom hypoxia, that is dissolved oxygen less than 61 µmol kg−1 and harmful to marine animals, was observed over nearly half of the continental shelf inshore of the 200-m isobath, covering 15,500 square kilometers. A mid-shelf ribbon with near-bottom, dissolved oxygen less than 50 µmol kg−1 extended for 450 km off north-central Oregon and Washington. Spatial patterns in near-bottom oxygen are related to the continental shelf width and other features of the region. Maps of near-bottom oxygen since 1950 show a consistent trend toward lower oxygen levels over time. The fraction of near-bottom water inshore of the 200-m isobath that is hypoxic on average during the summer upwelling season increases over time from nearly absent (2%) in 1950–1980, to 24% in 2009–2018, compared with 56% during the anomalously strong upwelling conditions in 2021. Widespread and increasing near-bottom hypoxia is consistent with increased upwelling-favorable wind forcing under climate change.

Offshoring emissions through used vehicle exports, Newman et al., Nature Climate Change:

Policies to reduce transport emissions often overlook the international flow of used vehicles. We quantify the rate at which used vehicles generated CO2 and pollution for all used vehicles exported from Great Britain—a globally leading used vehicle exporter—across 2005–2021. Destined for low–middle-income countries, exported vehicles fail roadworthiness standards and, even under extremely optimistic ‘functioning-as-new’ assumptions, generate at least 13–53% more emissions than scrapped or on-road vehicles.

Translating climate risk assessments into more effective adaptation decision-making: The importance of social and political aspects of place-based climate risk, Kythreotis et al., Environmental Science & Policy:

Climate risk continues to be framed ostensibly in terms of physical, socio-economic and/or ecological risks, as evidenced in the 2012 and 2017 UK Climate Change Risk Assessment (CCRA) evidence reports. This article argues that framing climate risk in this way remains problematic for the science-policy process, particularly in ensuring adequate climate risk assessment information translates into more effective adaptation decision-making. We argue how climate risk assessments need to further consider the social and political aspects of place-based climate risk to ensure more effective adaptation policy outcomes. 

From this week's government/NGO section:

Carbon Clean 200®: Investing In a Clean Energy Future 2024 Performance UpdateHeaps et al., As You Sow:

The Clean200 lists the 200 major corporate players from 35 countries around the world that are at the forefront of this [energy] transition. These are the companies that are leading the way by putting sustainability at the heart of their products, services, business models, and investments, helping to move the world onto a more sustainable trajectory. 

Agenda for a Progressive Political Economy of Carbon RemovalNawaz et al., Institute for Responsible Carbon Removal, American University:

Large amounts of carbon dioxide will need to be removed and durably stored to meet climate targets. Even the lowest estimates suggest that large new industries will need to be created to produce these removals. As both private and public investments begin to fill this gap, the foundations of an emerging carbon removal industry are now being laid via policy decisions that will shape the field to come. The authors examine the possible versions of a future with carbon removal, imagining its best forms, its worst forms, and its most likely forms.

135 articles in 66 journals by 766 contributing authors

Physical science of climate change, effects

Underlying physical mechanisms of winter precipitation extremes over India's high mountain region, Nischal et al., Quarterly Journal of the Royal Meteorological Society 10.1002/qj.4661

Observations of climate change, effects

Unprecedented wildfires in Korea: Historical evidence of increasing wildfire activity due to climate change, Chang et al., Agricultural and Forest Meteorology 10.1016/j.agrformet.2024.109920



How oil sands undermine Canada’s climate goals

Posted on 21 February 2024 by dana1981

This is a re-post from Yale Climate Connections

Now in his ninth year as prime minister, Justin Trudeau has sought to position Canada as a global climate leader, touting one of the world’s highest taxes on carbon pollution, clean fuel regulations, and clean technology tax credits. Yet Canada’s per-person climate pollution remains stubbornly near the top of the list of developed countries — alongside the United States and Australia, whose governments have been less consistently supportive of climate solutions over the past decade.

Climate Action Tracker, an independent project that monitors whether governments’ actions measure up to the goals outlined in the Paris climate agreement, rates Canada’s climate policies as “highly insufficient.” The project noted, “If all countries were to follow Canada’s approach, warming could reach over 3°C and up to 4°C” — a potentially catastrophic level of global warming. The Trudeau government has pledged to cut emissions by at least 40-45% below 2005 levels by 2030 but is not on track to meet that goal.

This raises the question: What’s holding back Canada’s climate ambitions? Although there are numerous contributing factors, Climate Action Tracker points to one primary culprit, arguing that “Canada seems incapable of kicking its oil and gas addiction.” Canada is the fourth-largest producer of oil and the fifth-largest producer of methane gas, commonly called natural gas, in the world. Nearly 80% of Canadian oil is exported to the United States, and fossil fuels account for over one-fifth of the country’s exports, worth over $100 billion per year.

So the country exemplifies the challenge of solving the climate crisis even when relatively climate-aware governments are in power.



At a glance - Was Greenland really green in the past?

Posted on 20 February 2024 by John Mason, BaerbelW

On February 14, 2023 we announced our Rebuttal Update Project. This included an ask for feedback about the added "At a glance" section in the updated basic rebuttal versions. This weekly blog post series highlights this new section of one of the updated basic rebuttal versions and serves as a "bump" for our ask. This week features "Was Greenland really green in the past?". More will follow in the upcoming weeks. Please follow the Further Reading link at the bottom to read the full rebuttal and to join the discussion in the comment thread there.

Fact-Myth Box

At a glance

The past 2024 years - i.e. everything AD - are referred to by archaeologists as the Common Era (CE). Decades ago, long before the refinements and data-coverage of modern science, the CE was divided into a series of climate epochs. Among these were the 'Mediaeval Warm Period' (MWP), from around 800-1200 CE and the 'Little Ice-Age', from 1200-1850 CE.

Each of these epochs has the origin of its name in older paleoclimatic evidence from the Northern Hemisphere and particularly Europe. But things have moved on. We now know that unlike modern global warming, the MWP was regional in its nature. A particularly warm region was the Northern Atlantic, including southern Greenland.

Icelandic sagas tell how, in 982 CE, Erik the Red was sentenced to exile from Iceland for three years. He had been involved in an escalated dispute with a neighbour that had culminated in several deaths. With a band of fellow Vikings, he set sail towards Greenland. Erik's party landed and settled near the mouth of Tunulliarfik Fjord, which has the modern Innuit settlement of Narsarsuaq at its head. This part of Greenland is a largely ice-free enclave today, situated in the SW part of the island, some 200 km from its southern tip. Legend tells how Erik came up with the name, 'Greenland', in order to attract further settlers. Apparently the ploy worked.

With hundreds of settlers arriving in the SW of Greenland, a mixed economy developed. It was based on combined pastoral farming, hunting and fishing. Livestock were kept mostly for milk, cheese and butter. Meat instead came mostly from hunting, both locally and in seasonal expeditions further north. These longer forays visited areas in which walrus, narwhal and polar bears were abundant. Hides and ivory became export commodities, allowing maritime trade with the rest of Europe, in return for iron, timber and other essentials.

A few centuries into this colonisation, the regional climate deteriorated. Ice-sheets readvanced. Recent research has also shown that sea-levels rose, too. It may seem counter-intuitive, but when ice sheets grow, nearby coasts often drown. Two things work together to cause this: the larger gravitational pull of all the extra ice on the sea surface and the subsidence of Earth's crust due to the added weight of that ice. One recent study has suggested over 200 square kilometres of coastal land - where the settlers would have had many of their farms - were lost. Geophysics has detected remains of some of the settlements, now beneath the waves.

Progressive sea-level rise, likely in tandem with social and environmental factors such as famines, epidemics and harsher weather, took its toll. The Inuit, who had arrived in around 1200 CE, remained in Greenland through the severe cold of the Little Ice Age but by around 1500 CE, the Vikings had vanished for good. Climate change drove them out.

That's what happened to the Vikings. But regional and global climate change are different things. Regional historic change has little bearing on the global events that are happening right now.

Please use this form to provide feedback about this new "At a glance" section. Read a more technical version below or dig deeper via the tabs above!

Click for Further details



The promise of passive house design

Posted on 19 February 2024 by Guest Author

This is a re-post from Yale Climate Connections by Sarah Wesseler

Imagine a home so efficient that it could be heated with a hair dryer.

That’s the promise of a passive house, a design standard that’s becoming increasingly popular in the architecture community for its benefits to occupants and the climate.

In passive house buildings, an airtight facade prevents unwanted flows of energy between the interior and exterior — a marked break with typical structures that let heat in during the summer and leak it out during the winter.

“Passive house is the most reliable, cost-effective, and healthiest way to reach superb energy performance in architecture,” said Sara Bayer, the director of sustainability at New York City design firm Magnusson Architecture and Planning.

Some policymakers are taking notice.

Buildings are a major source of planet-warming emissions. Reducing the amount of energy needed to maintain comfortable temperatures, keep the lights on, and provide other critical services is vital to meeting governments’ climate goals.

In recent years, Massachusetts has become a leader in promoting passive house design. The standard is a natural fit for the government’s building efficiency push, said Beverly Craig, a program director at the state-run Massachusetts Clean Energy Center.

“We can be sure when we build to passive house standards that we’re going to get 40 to 60% less energy use per square foot than what we traditionally have for [building] code,” she said.



2024 SkS Weekly Climate Change & Global Warming News Roundup #07

Posted on 18 February 2024 by BaerbelW

A listing of 31 news and opinion articles we found interesting and shared on social media during the past week: Sun, Feb 11, 2024 thru Sat, Feb 17, 2024.

Story of the week

Based on mission alignment, our Story of the Week is certainly Can we be inoculated against climate misinformation? Yes – if we prebunk rather than debunk, published in The Conversation and authored by Christian Turney of the University of Technology, Sydney and Sander van der Linden of Cambridge University. The article parallels Skeptical Science and our emphasis on solidly actionable theory and tested methods of neutralizing misinformation - it starts at why and concludes with how. In the authors' words, the big picture "why learn this?" comes down to:

"Social media and the open internet have made it possible to broadcast information to millions of people, regardless of whether it’s true. It’s no wonder it’s a golden age for misinformation. Misinformation actors have found effective ways to cast scepticism on established science and then sell a false alternative.

"We have to respond. Doing nothing means the lies win. And getting on the front foot with prebunking is one of the best tools we have."

A few minutes spent reading this article will leave us better armed, informed by expert "virologists" studying inoculation against bunk. 

Stories we promoted this week, by publication date:

Published before February 11

February 11



Can we be inoculated against climate misinformation? Yes – if we prebunk rather than debunk

Posted on 16 February 2024 by Guest Author

This article is republished from The Conversation under a Creative Commons license. Read the original article written by Christian Turney, University of Technology Sydney and Sander van der Linden, University of Cambridge and first published on February 14, 2024.

Adrien Demers/Shutterstock

Last year, the world experienced the hottest day ever recorded, as we endured the first year where temperatures were 1.5°C warmer than the pre-industrial era. The link between extreme events and climate change is clearer than ever. But that doesn’t mean climate misinformation has stopped. Far from it.

Misleading or incorrect information on climate still spreads like wildfire, even during the angry northern summer of 2023. Politicians falsely claimed the heatwaves were “normal” for summer. Conspiracy theorists claimed the devastating fires in Hawaii were ignited by government lasers.

People producing misinformation have shifted tactics, too, often moving from the old denial (claiming climate change isn’t happening) to the new denial (questioning climate solutions). Spreading doubt and scepticism has hamstrung our response to the enormous threat of climate change. And with sophisticated generative AI making it easy to generate plausible lies, it could become an even bigger issue.

The problem is, debunking misinformation is often not sufficient and you run the risk of giving false information credibility when you have to debunk it. Indeed, a catchy lie can often stay in people’s heads while sober facts are forgotten.

But there’s a new option: the prebunking method. Rather than waiting for misinformation to spread, you lay out clear, accurate information in advance – along with describing common manipulation techniques. Prebunking often has a better chance of success, according to recent research from co-author Sander van Linden.

How does prebunking work?

Misinformation spreads much like a virus. The way to protect ourselves and everyone else is similar: through vaccination. Psychological inoculation via prebunking acts like a vaccine and reduces the probability of infection. (We focus on misinformation here, which is shared accidentally, not disinformation, which is where people deliberately spread information they know to be false).



Skeptical Science New Research for Week #7 2024

Posted on 15 February 2024 by Doug Bostrom, Marc Kodack

Open access notables

Physics-based early warning signal shows that AMOC is on tipping course, van Westen et al., Science Advances:

Here, we show results of the first tipping event in the Community Earth System Model, including the large climate impacts of the collapse. Using these results, we develop a physics-based and observable early warning signal of AMOC tipping: the minimum of the AMOC-induced freshwater transport at the southern boundary of the Atlantic. Reanalysis products indicate that the present-day AMOC is on route to tipping. The early warning signal is a useful alternative to classical statistical ones, which, when applied to our simulated tipping event, turn out to be sensitive to the analyzed time interval before tipping.

The growing inadequacy of an open-ended Saffir–Simpson hurricane wind scale in a warming world, Wehner & Kossin, Proceedings of the National Academy of Sciences:

Global warming increases available sensible and latent heat energy, increasing the thermodynamic potential wind intensity of tropical cyclones (TCs). Supported by theory, observations, and modeling, this causes a shift in mean TC intensity, which tends to manifest most clearly at the greatest intensities. The Saffir–Simpson scale for categorizing damage based on the wind intensity of TCs was introduced in the early 1970s and remains the most commonly used metric for public communication of the level of wind hazard that a TC poses. Because the scale is open-ended and does not extend beyond category 5 (70 m/s windspeed or greater), the level of wind hazard conveyed by the scale remains constant regardless of how far the intensity extends beyond 70 m/s. This may be considered a weakness of the scale, particularly considering that the destructive potential of the wind increases exponentially. 

Using climate financing wisely to address multiple crises, Läderach et al., PLOS Climate:

The existing international architecture of climate change mitigation and adaptation policy and financing holds, in principle, the potential to address not only its main purpose of climate action, but also to contribute to development outcomes and address multiple risk drivers. Examples of this exist, but for these mutual benefits to emerge, and for climate finance to contribute more significantly to crises prevention, the agendas must become more aligned. Aligning several factors may enable coherence: i) Timeframes, from short-term response to multi-year programming; ii) Planning and targeting, moving towards conflict-sensitive area-based approaches and universal access to services; iii) Institutional arrangements and partnerships, coordinated national planning and jointly implemented local action.

Phase-Locked Rossby Wave-4 Pattern Dominates the 2022-Like Concurrent Heat Extremes Across the Northern Hemisphere, Yang et al., Geophysical Research Letters:

118 articles in 60 journals by 661 contributing authors

Physical science of climate change, effects

Arctic marine heatwaves forced by greenhouse gases and triggered by abrupt sea-ice melt, Barkhordarian et al., Communications Earth & Environment Open Access pdf 10.1038/s43247-024-01215-y

Drivers of Marine Heatwaves in the Arctic Ocean, Richaud et al., 10.5194/egusphere-egu23-5780



New study suggests the Atlantic overturning circulation AMOC “is on tipping course”

Posted on 14 February 2024 by Guest Author

This is a re-post from RealClimate by Stefan Rahmstorf

A new paper was published in Science Advances today. Its title says what it is about: “Physics-based early warning signal shows that AMOC is on tipping course.” The study follows one by Danish colleagues which made headlines last July, likewise looking for early warning signals for approaching an AMOC tipping point (we discussed it here), but using rather different data and methods.

The new study by van Westen et al. is a major advance in AMOC stability science, coming from what I consider the world’s leading research hub for AMOC stability studies, in Utrecht/Holland. (Some of their contributions spanning the past 20 years are in the paper’s reference list, with authors Henk Dijkstra, René van Westen, Nanne Weber, Sybren Drijfhout and more.)

The paper results from a major computational effort, based on running a state-of-the-art climate model (the CESM model with horizontal resolution 1° for the ocean/sea ice and 2° for the atmosphere/land component) for 4,400 model years. This took 6 months to run on 1,024 cores at the Dutch national supercomputing facility, the largest system in the Netherlands in terms of high-performance computing.

It is the first systematic attempt to find the AMOC tipping point in a coupled global ocean-atmosphere climate model of good spatial resolution, using the quasi-equilibrium approach which I pioneered in 1995 with an ocean-only model of relatively low resolution, given the limited computer power available 30 years ago.

If you’re not familiar with the issues surrounding the risk of abrupt ocean circulation changes, I briefly summarized ten key facts on this topic last year in this blog post.

Fig. 1. Schematic of the AMOC, with warm water flowing north, sinking in northern latitudes and then returning as a cold deep current to the south. The background map shows the sea surface temperature change since 1870 based on ocean observations, including the AMOC slowdown fingerprint of a ‘cold blob’ in the subpolar North Atlantic and excessive warming north of the Gulf Stream. Figure adapted from Caesar et al., Nature 2018.

But now, let’s get straight to the main findings of the new paper:



At a glance - Has Arctic sea ice returned to normal?

Posted on 13 February 2024 by John Mason, BaerbelW

On February 14, 2023 we announced our Rebuttal Update Project. This included an ask for feedback about the added "At a glance" section in the updated basic rebuttal versions. This weekly blog post series highlights this new section of one of the updated basic rebuttal versions and serves as a "bump" for our ask. This week features "Has Arctic sea ice returned to normal?". More will follow in the upcoming weeks. Please follow the Further Reading link at the bottom to read the full rebuttal and to join the discussion in the comment thread there.

Fact Myth Box

At a glance

One of the great metrics of climate change, because it is easy to visualise, is sea-ice in the Arctic. Every year, the ice margins retreat in the northern summer, reaching a minimum extent some time in September. It then refreezes through the long, dark cold winter months, until its maximum extent is reached in March.

Arctic sea-ice has a seasonal component - so-called 'first year ice' - and the more perennial 'multi-year ice'. First-year ice is relatively thin - 30-40 centimetres is typical. Multi-year stuff is thicker - 2-4 metres and much of it is situated between the north coast of Greenland and the North Pole.

Most of the annual, seasonal decline in ice extent, observed by satellites for more than 40 years, is due to first-year ice melting: the more robust multi-year ice takes more energy to remove, but nevertheless it is in decline, too. Calculations of sea-ice volume reveal that trend.

How does sea-ice form? We all know the freezing temperature of saltwater is lower than that of freshwater, hence the spreading of rock salt on the roads on frosty winter nights. Similarly, the ocean temperature needs to fall below -1.8°C (28.8°F) for sea-ice to form. In the freezing season it starts freezing over once the upper 150 metres or so of the ocean are close to that temperature.

Melt varies a lot from one year to another. This should come as no surprise: sea-ice, being on an ocean, moves about a fair amount. Variations in ocean-currents are particularly important since if sea-ice can be 'exported' out of the Arctic, it enters what is basically a hostile environment, where it melts away to nothing. Incidentally, such floes are a lot smaller than icebergs like the one that famously destroyed the Titanic in April 1912. Such ice behemoths originate where glaciers 'calve' upon reaching the sea.

Weather is a highly variable driver of sea-ice melt. Prolonged strong winds from the right direction can cause mass-export of ice into warmer waters. Then again, winds from the south transport warm air over the Arctic Ocean, causing the melting to intensify. But they may also bring in extensive cloud-decks, blocking a lot of incoming Solar energy. No surprise then that melt seasons vary a lot from one season to another.

As in most things related to climate change, it's the multidecadal trend that is key and that is unequivocally downwards, both in terms of extent and volume. Sudden spurts of growth are interesting, as are record meltdowns such as that in 2012. But that's it. Trend is the critical bit. The data clearly show that since 2010, when the statement in the box above originated, eight out of the ten lowest Arctic sea-ice minima have occurred. The only two melt-seasons outside of that time-frame were in 2007 and 2008. For the big picture regarding Arctic sea-ice, ignore the noise from one year to the next and look at all the data. It's heading one way - down.

Please use this form to provide feedback about this new "At a glance" section. Read a more technical version below or dig deeper via the tabs above!

Click for Further details



After years of stability, Antarctica is losing ice

Posted on 12 February 2024 by

This is a re-post from Yale Climate Connections by SueEllen Campbell

Until recently, Antarctica’s ice has seemed surprisingly stable. In contrast to the far north, the southern continent’s massive ice sheets, glaciers, ice shelves (ice that floats on the ocean), and seasonal ice appeared to be reliably frozen: Enough snow fell in the high interior to compensate for what melted around the edges. 

But the situation has changed. On balance, Antarctica is now losing ice. And more and more, scientists are concerned about that melting and its potential impacts — from sea level rise to changed ocean and air circulation to stress on wildlife — both local and global. Knowing that there is still much to learn, they are stepping up their research, despite the massive challenges in learning anything in such extreme conditions.

Winter 2023: record-low sea ice

Where did all the Antarctic sea ice go?” “Full Story” podcast, The Guardian. This excellent 19-minute interview by Laura Murphy-Oates with Graham Readfearn (The Guardian’s Australia environment writer) and oceanographer Will Hobbs clearly explains both the anomalous loss of southern sea ice last winter and its larger possible ramifications. 

For a print account of the same situation, see “Dark waters as Antarctic researchers dive into grim climate picture.” Matthew Ward Agius, Cosmos. 



2024 SkS Weekly Climate Change & Global Warming News Roundup #06

Posted on 11 February 2024 by BaerbelW

A listing of 34 news and opinion articles we found interesting and shared on social media during the past week: Sun, Feb 04, 2024 thru Sat, Feb 10, 2024.

Story of the week

This past week Professor Michael Mann successfully concluded his lawsuit against fossil fuel industry proxies Rand Simberg and Mark Steyn, who dragged Mann's reputation through the mud with false information while working to deceive the public about the threat of climate change. After hearing testimony about the disgusting tactics employed by the defendants, the jury swiftly returned their judgement: the accused are indeed guilty of smearing Mann's character and owe him $1M in damages. No surprise, this all-too-rare example of reckless accusations being assigned a fair price tag is our story of the week. Our colleagues at DeSmog have done the best job of covering the entire affair. See Michael Mann Wins $1 Million Verdict In Defamation Trial for excellent coverage of the trial's conclusion and background. For our part we'll observe that Prof. Mann has a long memory and attention span. Meanwhile, prolonging justice delivered only hurt the defendants; Simberg and Steyn would have been smarter by settling years ago. 

Stories we thought important

Published before February 4

Published February 4



The Teachers' Guide to Cranky Uncle: Downloads and Translations

Posted on 9 February 2024 by BaerbelW

Update February 9, 2024: The Teacher's Guide to Cranky Uncle is now also available in Albanian and Macedonian, thanks to the efforts of the Institute of Communication studies in Skopje!

CrankyGuide-EN-ThumbPublished in January 2021, The Teachers' Guide to Cranky Uncle offers background information and classroom activity ideas for educators interested in using the Cranky Uncle game to teach critical thinking in their classes.

The Cranky Uncle game builds resilience against misinformation and strengthens players’ critical thinking. It achieves this through inoculation—explaining the rhetorical techniques used to mislead. The denial techniques in the game are built  on the five techniques of science denial outlined in the FLICC framework.

One of the activities in the Teachers’ Guide is the Please Don’t Fail Me assignment, designed by Melanie Trecek-King from Thinking is Power. Melanie has also written a blog post going into greater detail into this assignment and how students responded.

Other suggested activities include

  • Introduction to FLICC
  • Walk-through game
  • Roleplaying
  • Have students create misinformation
  • Debunking misinformation
  • ... and more

Download Cranky Guide




Skeptical Science New Research for Week #6 2024

Posted on 8 February 2024 by Doug Bostrom, Marc Kodack

Open access notables

300 years of sclerosponge thermometry shows global warming has exceeded 1.5 °C, McCulloch et al., Nature Climate Change: 

Using 300 years of ocean mixed-layer temperature records preserved in sclerosponge carbonate skeletons, we demonstrate that industrial-era warming began in the mid-1860s, more than 80 years earlier than instrumental sea surface temperature records. The Sr/Ca palaeothermometer was calibrated against ‘modern’ (post-1963) highly correlated (R2 = 0.91) instrumental records of global sea surface temperatures, with the pre-industrial defined by nearly constant (<±0.1 °C) temperatures from 1700 to the early 1860s. Increasing ocean and land-air temperatures overlap until the late twentieth century, when the land began warming at nearly twice the rate of the surface oceans. Hotter land temperatures, together with the earlier onset of industrial-era warming, indicate that global warming was already 1.7 ± 0.1 °C above pre-industrial levels by 2020. Our result is 0.5 °C higher than IPCC estimates, with 2 °C global warming projected by the late 2020s, nearly two decades earlier than expected.

Record High 2022 September-Mean Temperature in Western North America, Xie et al., Bulletin of the American Meteorological Society:

Human-induced warming is estimated to have increased occurrence probability (magnitude) of the record-breaking September 2022 heat event in western North America by 6–67 times (0.6–1 K) by E3SMv2 and even higher by coupled regional refined model (RRM) simulations.

Spectrally refined unbiased Monte Carlo estimate of the Earth’s global radiative cooling, Nyffenegger-Péré et al., Proceedings of the National Academy of Sciences:

The Earth’s radiative cooling is a key driver of climate. Determining how it is affected by greenhouse gas concentration is a core question in climate-change sciences. Due to the complexity of radiative transfer processes, current practices to estimate this cooling require the development and use of a suite of radiative transfer models whose accuracy diminishes as we move from local, instantaneous estimates to global estimates over the whole globe and over long periods of time (decades). Here, we show that recent advances in nonlinear Monte Carlo methods allow a paradigm shift: a completely unbiased estimate of the Earth’s infrared cooling to space can be produced using a single model, integrating the most refined spectroscopic models of molecular gas energy transitions over a global scale and over years, all at a very low computational cost (a few seconds).

Which energy labels should we use to expedite the transition to electric vehicles?, Scarlat et al., Frontiers in Environmental Science:

Efforts to promote electric vehicle adoption through policy measures fall short due to underestimated cognitive biases and consumer behavior impacts. We contribute to the literature by bridging the gap between human behavioral studies and environmental policy. We incorporate choice architecture into energy labels to determine which information architecture regarding energy costs is an effective nudge in increasing electric vehicle purchase intentions. Our experiment finds that labels framing energy costs as ‘expenditure,’ rather than ‘savings,’ are more effective in increasing the intent to purchase an electric vehicle. Additionally, we find that a graphical display of expenditure was not effective in influencing purchase intentions. Policymakers can use similar choice architecture tools to encourage electric vehicle adoption, expediting the transition to electric vehicles and achieving national environmental goals.

Absurd geographies of resilience and justice, Grove et al., Climate and Development:

Critical and applied scholarship tends to dismiss resilience as a neoliberal barrier to justice, or assume it necessarily advances justice outcomes. Instead, drawing on collaborative fieldwork with Miami-based social and climate justice organizers, we explore how resilience is mobilized in contextually-specific struggles against racialized vulnerability and insecurity. Reading across literatures in political geography, cultural geography, and Black geographies, we highlight absurd and inconsistent expressions of resilience in our collaborators’ justice advocacy work. A focus on the absurd directs attention to the way diverse practices of resilience emerge from ‘spaces out of joint,’ where modernity’s universalizing promises of betterment run aground against long histories of racial violence that secure White futurity. Our community collaborators ironically mobilize and reject resilience in strategic ways that reflect their struggles to create and defend place against the racialized extraction of value, disinvestment, and displacement.

A Realist Approach to HydrogenRobin Gaster, e Information Technology and Innovation Foundation (via this week's government/NGO section):

Clean hydrogen is expensive to produce, difficult to transport, and a second- or third-best clean energy solution in almost all proposed markets. To help drive the global green transition, a realist approach to hydrogen policy must address all these practical challenges. Blue hydrogen investments should be minimized. Blue hydrogen is not a global solution for greenhouse gas emissions even in targeted industries, as it will never reach price/performance parity (P3) with gray hydrogen, and may not effectively address greenhouse gases either. Green hydrogen is different. It could reach P3, for some applications, in some regions. But that depends almost entirely on lower costs for the renewable energy it requires, the key input. Economies of scale, e.g., for electrolyzes, will not transform the economics of green hydrogen. Most proposed markets for hydrogen reflect magical thinking. They are nowhere near competitive with fossil fuels and often are not competitive with electrification using renewable energy. Accelerating research, design and development around green hydrogen is critical, emphasizing the competitive pathway to scaleup for a few key potential markets, such as long-duration energy storage. Policymakers should favor projects that co-locate green hydrogen production, energy sources, and end users, avoiding projects that require electricity from the grid or extensive transportation infrastructure. 

246 articles in 79 journals by 1791 contributing authors

Physical science of climate change, effects

Arctic Sea Ice Loss, Long-Term Trends in Extratropical Wave Forcing, and the Observed Strengthening of the QBO-MJO Connection, Hood & Hoopes, Journal of Geophysical Research: Atmospheres 10.1029/2023jd039501

Comparison of the opposite behaviours of Korean heatwaves with extreme hot sea surface temperatures in August 2016 and 2022, Choi & Lee, International Journal of Climatology Open Access 10.1002/joc.8247

Examining cloud vertical structure and radiative effects from satellite retrievals and evaluation of CMIP6 scenarios, Luo et al., Atmospheric Chemistry and Physics Open Access 10.5194/acp-23-8169-2023

High-Resolution Lead–Lag Relations Between Barents Sea Temperatures, the AMOC and the AMO During 1971–2018, Seip & Wang, Atmosphere Open Access 10.1080/07055900.2023.2251426



Climate Adam: Eco-Emotions: How we deal with climate fears

Posted on 7 February 2024 by Guest Author, BaerbelW

This video includes conclusions of the creator climate scientist Dr. Adam Levy. It is presented to our readers as an informed perspective. Please see video description for references (if any).

Understanding climate change and how we're unravelling our world is gruelling. And to work as a climate scientist and communicator means you're constantly juggling emotions - from hope to climate anxiety. So where do we find our hope and our courage to continue? And how can we manage our feelings so that working on global warming is not only bearable, but brilliant!

Support ClimateAdam on patreon:

Check out Ella: @DrGilbz

And check out the videos we mentioned!

On Atlantic Meridional Overturning Circulation (AMOC):

On the West Antarctic



At a glance - What climate change is happening to other planets in the solar system?

Posted on 6 February 2024 by John Mason, BaerbelW

On February 14, 2023 we announced our Rebuttal Update Project. This included an ask for feedback about the added "At a glance" section in the updated basic rebuttal versions. This weekly blog post series highlights this new section of one of the updated basic rebuttal versions and serves as a "bump" for our ask. This week features "What climate change is happening to other planets in the solar system?". More will follow in the upcoming weeks. Please follow the Further Reading link at the bottom to read the full rebuttal and to join the discussion in the comment thread there.

Fact Myth Box

At a glance

Experienced students of climate science denial will be familiar with many of the arguments that contrarians use. But every now and then you come across a document so crammed with such talking points that they're like raisins in a Christmas pudding. So it is with the 8-page offering containing the above quote, dating from June 2009.

But 2009 is a long time ago now. So much so that one of the big statements in that document:

"With the Sun now entering a ‘quiet’ phase, it is anticipated that this cooling trend is likely to continue until Sun activity increases."

is self-evidently a complete fail, given that according to NOAA, all of the ten warmest years in a data record stretching back to the late 19th century have been since 2010.

That the document is a complete fail, as evidenced by the above quote, is one thing. But how about the claim that the other planets are warming? This is a weird one, given the impossible expectations demanded of those tasked with recording temperatures here on Earth. Accusations of badly-sited weather stations, data manipulation and similar conspiracy-theories abound out there in various dimly-lit corners of cyberspace. But then you get a document from the same stable that claims Pluto is warming up. What's that based on?

Pluto takes 248 years to complete a single orbit around the Sun. Since the body was discovered in 1930, a simple calculation shows we've had the chance to point our telescopes at it for 37.5% of a Plutonian year, so if the place had four seasons then we've not yet seen half of them.

Apart from remote observations made in 1988 and 2002, we did send the New Horizons NASA spacecraft out there in 2006, to make a flyby of the dwarf planet in 2015. It collected lots of useful data in the process, but three sets of observations over 27 years means just what?

Twenty-seven years is just one ninth of a single year on Pluto. On Earth that would be 40 days. What could you say about the climate from that? Wild and unsubstantiated claims, based on very little data, might fool some people but the advantage these days is that they can be fact-checked and quickly. Nonsensical statements thereby reveal themselves to be just that.

Finally, in the 2009 document, all talking-points converge on a single hypothesis - that the Sun is responsible for the current global warming. Only one problem with that, but it's a huge one. Solar energy output is expressed as 'total Solar irradiance' (TSI) and is easily measured by satellites. Since 1980, TSI and global temperatures have diverged. TSI has decreased by a measurable amount, while the global temperature has continued on its erratic but upwards pathway.

It's not the Sun - it's our cranking out of greenhouse gases in their tens of billions of tonnes every year, on and on and on.

Please use this form to provide feedback about this new "At a glance" section. Read a more technical version below or dig deeper via the tabs above!

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Looking to take advantage of IRA rebates? Depending on your state, you might have to wait.

Posted on 5 February 2024 by Guest Author

This is a re-post from Yale Climate Connections by Samantha Harrington

If you’re planning to make your home more climate-friendly, new rebates could soon help you save thousands of dollars on those improvements. But first, your state or territory must design a rebate program. And the timeline for getting those programs up and running is still murky.  

The rebate program will be funded under provisions in the Inflation Reduction Act, landmark legislation that Democrats passed in 2022 to address climate change. It incentivizes Americans to cut pollution by adopting cleaner electric appliances and making their homes more energy efficient. Under the law, federal tax credits and point-of-sale rebates will make those improvements cheaper. Low-income households, for example, may qualify for an $8,000 rebate on heat pumps, though final rebate amounts will be determined by the states. The rebates will be available at the point of purchase, meaning that customers won’t need to wait until tax season to reap the cost savings. 

Tax credits for solar panels, electric appliances, EVs, home energy audits, and more went into effect in 2023. But rebates programs are taking longer because each state or territory must design and run its own program.

So where are the rebates, and when might you expect to be able to claim them?



2024 SkS Weekly Climate Change & Global Warming News Roundup #05

Posted on 4 February 2024 by BaerbelW

A listing of 34 news and opinion articles we found interesting and shared on social media during the past week: Sun, Jan 28, 2024 thru Sat, Feb 03, 2024.

Story of the week

When we started our rebuttals update project at Skeptical Science last year, we didn't really know, how it would pan out and for how long we could keep the refurbishing line in our little virtual factory going. Now, almost a year after we published the first batch of 10 updated rebuttals we hit highlighted rebuttal #50 this week, so our effort thus far has proven to be sustainable. In addition, we are happy to report that we have about 25 more rebuttals in various draft stages awaiting their turn to be highlighted. Our factory will therefore not be running out of material any time soon! 

Stories we thought important

Published before January 28

Published January 28



Skeptical Science New Research for Week #5 2024

Posted on 1 February 2024 by Doug Bostrom, Marc Kodack

Open access notables

The Weather–Climate Schism, Randall & Emanuel, Bulletin of the American Meteorological Society (perspective):

The atmospheric science community includes both weather and climate scientists. These two groups interact much less than they should, particularly in the United States. The schism is widespread and has persisted for 50 years or more. It is found in academic departments, laboratories, professional societies, and even funding agencies. Mending the schism would promote better, fasTter science. We sketch the history of the schism and suggest ways to make our community whole.

Bayesian Estimation of Advanced Warning Time of Precipitation Emergence, Lickley & Fletcher, Earth's Future:

Our approach uses individual model projections that show change before averaging across models to calculate ToE. It then applies a Bayesian method to constrain uncertainty from climate model ensembles using a perfect model approach. Results demonstrate the potential for widespread and decades-earlier precipitation emergence, with potential for end-of-century emergence to occur across 99% of the Earth compared to 60% in previous estimates. Our method reduces uncertainty in the direction of change across 8% of the globe. We find positive estimates of AWT across most of the Earth; however, in 34% of regions there is potential for no advanced warning before new precipitation regimes emerge. These estimates can guide adaptation planning, reducing the risk that policymakers are unprepared for precipitation changes that occur earlier than expected.

How Economics Can Tackle the ‘Wicked Problem’ of Climate ChangeStiglitz et al., School of International and Public Affairs/Institute of Global Politics, Columbia University (from this week's government/NGO section):

Addressing the harmful effects of climate change requires an understanding of economic tradeoffs, the politics of policymaking, and the strategy of diplomacy. While early prescriptions for climate solutions focused on idealistic “optimal” policies and all-encompassing global treaties, a more nuanced and realistic vision for climate progress has emerged. As befits a “wicked problem,” a wide range of policies and insights from across scientific disciplines are needed to promote collective action, reduce emissions, and help the world achieve a more sustainable future.

The Russia-Ukraine war decreases food affordability but could reduce global greenhouse gas emissions, van Meijl et al., Communications Earth & Environment:

The scenarios assess the possible consequences of macro-economic and agricultural production impacts in Ukraine, trade sanctions against Russia, and conflict-related energy price developments for global trade, food security, and greenhouse gas emissions. From a food security perspective, we conclude that there is enough food on the global level, but higher food and energy prices cause problems for low-income populations, spending a large part of their income on staple foods. Agricultural production and area expansion in parts of the world other than Ukraine and Russia could pose a risk to biodiversity and lead to higher greenhouse gas emissions related to land. However, total greenhouse gas emissions might decrease as lower emissions from less use of fossil energy due to higher energy and fertilizer prices in the whole economy dominate additional emissions resulting from land use change.

High-altitude glacier archives lost due to climate change-related melting, Huber et al., Nature Geoscience 

Global warming has caused widespread surface lowering of mountain glaciers. By comparing two firn cores collected in 2018 and 2020 from Corbassière glacier in Switzerland, we demonstrate how vulnerable these precious archives of past environmental conditions have become. Within two years, the soluble impurity records were destroyed by melting. The glacier is now irrevocably lost as an archive for reconstructing major atmospheric aerosol components.

Searching for the Most Extreme Temperature Events in Recent History, Cattiaux et al., Bulletin of the American Meteorological Society:

Here we present an original method that objectively selects, defines, and compares extreme events that have occurred worldwide in the recent years. Building on previous work, the event definition consists of automatically selecting the spatiotemporal scale that maximizes the event rarity, accounting for the nonstationary context of climate change. We then explore all years, seasons, and regions and search for the most extreme events. We demonstrate how our searching procedure can be both useful for climate monitoring over a given territory, and resolve the geographical selection bias of attribution studies. Ultimately, we provide a selection of the most exceptional hot and cold events in the recent past, among which are iconic heatwaves such as those seen in 2021 in Canada and in 2003 in Europe.

134 articles in 59 journals by 833 contributing authors

Physical science of climate change, effects

Hurricane track trends and environmental flow patterns under surface temperature changes and roughness length variations, Romdhani et al., Weather and Climate Extremes Open Access 10.1016/j.wace.2024.100645

Influence of boreal summer monsoon intraseasonal oscillations on the occurrences of Marine Heatwave events over the North Bay of Bengal, Mandal et al., Climate Dynamics 10.1007/s00382-023-06945-x

Radiative effect of thin cirrus clouds in the extratropical lowermost stratosphere and tropopause region, Spang et al., Atmospheric Chemistry and Physics Open Access 10.5194/acp-24-1213-2024

The Respective Roles of Ocean Heat Transport and Surface Heat Fluxes in Driving Arctic Ocean Warming and Sea Ice Decline, Oldenburg et al., Journal of Climate 10.1175/jcli-d-23-0399.1

Observations of climate change, effects

A decade of marine inorganic carbon chemistry observations in the northern Gulf of Alaska – Insights to an environment in transition, Monacci et al., Earth System Science Data Open Access pdf 10.5194/essd-16-647-2024

Anthropogenic Contribution to the Unprecedented 2022 Midsummer Extreme High-Temperature Event in Southern China, Cao et al., Bulletin of the American Meteorological Society Open Access pdf 10.1175/bams-d-23-0199.1

Changes in regional daily precipitation intensity and spatial structure from global reanalyses, Lussana et al., International Journal of Climatology Open Access pdf 10.1002/joc.8375



50 Updated Rebuttals and Counting

Posted on 31 January 2024 by John Mason

The climate myth rebuttal published this week was the 50th in a long list of updated rebuttals.

Besides that, there are more than 25 in the queue for publication and newly-drafted rebuttals are accumulating at a rate of 1-2 per week as we churn our way through the long list of science-denial's talking points. So it's time for a short reflective post.

The Rebuttal Updates Factory

Graphic: jg

On the Assembly-line

Because many of these rebuttals are of a pre-2010 vintage, it's sad to have to record that many have needed a total rewrite. Not because they are 'bad' or anything like that. At the time of their original publication, they were highly accurate snapshots of the situation. It's just that more than 14 years have passed, far too little has been done to address the climate crisis and emissions (plus CO2 levels) have continued to track dramatically upwards. Also, there's a lot of new science to read, digest and explain. This all takes time.

Out-datedness cuts both ways, though. Many of the quotes from science-deniers - the myths presented in the beige-coloured box above each rebuttal - are of a similar vintage. Often, they involved confidently-made predictions, such as "we have entered a long-term cooling period".

Fast forward to now and it's obvious that many such confident predictions were one hundred percent wrong. Whether the deniers were aware of that at the time is an interesting philosophical question. Did they know they would be proven wrong but simply didn't care - or were they so convinced they were right that physics simply caught up with them in the end? Or a mixture? Discuss!



At a glance - The runaway greenhouse effect on Venus

Posted on 30 January 2024 by John Mason, BaerbelW

On February 14, 2023 we announced our Rebuttal Update Project. This included an ask for feedback about the added "At a glance" section in the updated basic rebuttal versions. This weekly blog post series highlights this new section of one of the updated basic rebuttal versions and serves as a "bump" for our ask. This week features "The runaway greenhouse effect on Venus". More will follow in the upcoming weeks. Please follow the Further Reading link at the bottom to read the full rebuttal and to join the discussion in the comment thread there.


At a glance

Earth: we take its existence for granted. But when one looks at its early evolution, from around 4.56 billion years ago, the fact that we are here at all starts to look miraculous.

Over billions of years, stars are born and then die. Our modern telescopes can observe such processes across the cosmos. So we have a reasonable idea of what happened when our own Solar System was young. It started out as a vast spinning disc of dust with the young Sun at its centre. What happened next?

Readers who look up a lot at night will be familiar with shooting stars. These are small remnants of the early Solar System, drawn towards Earth's surface by our planet's gravitational pull. Billions of years ago, the same thing happened but on an absolutely massive scale. Fledgeling protoplanets attracted more and more matter to themselves. Lots of them collided. Eventually out of all this violent chaos, a few winners emerged, making up the Solar System as we now know it.

The early Solar system was also extremely hot. Even more heat was generated during the near-constant collisions and through the super-abundance of fiercely radioactive isotopes. Protoplanets became so hot that they went through a completely molten stage, during which heavy elements such as iron sank down through gravity, towards the centre. That's how their metallic cores formed. At the same time, the displaced lighter material rose, to form their silicate mantles. This dramatic process, that affected all juvenile rocky planets, is known as planetary differentiation.

Earth and Venus are the two largest rocky planets. But at some point after differentiation and solidification of their magma-oceans, their paths diverged. Earth ended up becoming habitable to life, but Venus turned into a hellscape. What happened?

There's a lot we don't know about Venus. But what we do know is that the surface temperature is hot enough to melt lead, at 477 °C (890 °F). Atmospheric pressure is akin to that found on Earth - but over a kilometre down in the oceans. The orbit of Venus may be closer to the Sun but a lot of the sunlight bathing the planet is reflected by the thick and permanent cloud cover. Several attempts to land probes on the surface have seen the craft expire during descent or only a short while (~2 hours max.) after landing.

Nevertheless, radar has been used to map the features of the planetary surface and analyses have been made of the Venusian atmosphere. The latter is almost all carbon dioxide, with a bit of nitrogen. Sulphuric acid droplets make up the clouds. Many hypotheses have been put forward for the evidently different evolution of Venus, but the critical bit - testing them - requires fieldwork under the most difficult conditions in the inner Solar System.

One leading hypothesis is that early on, Venus experienced a runaway water vapour-based greenhouse effect. Water vapour built up in the atmosphere and temperatures rose and rose until a point was reached where the oceans had evaporated. In the upper atmosphere, the water (H2O) molecules were split by exposure to high-energy ultraviolet light and the light hydrogen component escaped to space.

With that progressive loss of water, most processes that consume CO2 would eventually grind to a halt, unlike on Earth. Carbon dioxide released by volcanic activity would then simply accumulate in the Venusian atmosphere over billions of years, creating the stable but unfriendly conditions we see there today.

Earth instead managed to hang onto its water, to become the benign, life-supporting place where we live. We should be grateful!

Please use this form to provide feedback about this new "At a glance" section. Read a more technical version below or dig deeper via the tabs above!

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