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Explaining climate change science & rebutting global warming misinformation

Scientific skepticism is healthy. Scientists should always challenge themselves to improve their understanding. Yet this isn't what happens with climate change denial. Skeptics vigorously criticise any evidence that supports man-made global warming and yet embrace any argument, op-ed, blog or study that purports to refute global warming. This website gets skeptical about global warming skepticism. Do their arguments have any scientific basis? What does the peer reviewed scientific literature say?


2021 SkS Weekly Climate Change & Global Warming News Roundup #3

Posted on 16 January 2021 by John Hartz

A chronological listing of news articles linked to on the Skeptical Science Facebook Page during the past week: Sun, Jan 10, 2021 through Sat, Jan 16, 2021

Editor's Choice

NASA says 2020 tied for hottest year on record — here’s what you can do to help

Wildfire CA

Photo by Michael Held on Unsplash

The report is in: 2020 tied with 2016 for the hottest year on record, according to an analysis by NASA published Thursday.

In 2020, the global average temperature was 1.84 degrees Fahrenheit warmer than the mean global temperature for the years between 1951-1980 (which is used as a baseline), NASA scientists at the Goddard Institute for Space Studies (GISS) in New York found.

In addition, “the last seven years have been the warmest seven years on record, typifying the ongoing and dramatic warming trend,” GISS Director Gavin Schmidt, said in a written statement released by NASA.

“The important things are long-term trends. With these trends, and as the human impact on the climate increases, we have to expect that records will continue to be broken.” 

Click here to access the entire article as originally published on the SNBC website. 

NASA says 2020 tied for hottest year on record — here’s what you can do to help by Catherine Clifford, CNBC, Jan 15, 2021



Guest post: How to ‘fairly’ share emissions from goods traded around the world

Posted on 15 January 2021 by Guest Author

This article, guest authored by Dr Michael Jakob, Dr Hauke Ward & Dr Jan C Stecke, was originally published on the Carbon Brief website on Jan 4, 2021. It is reposted below in its entirety. Click here to access the original article and comments.

Container ship dock

Photo by Kingsley Jebaraj on Unsplash

Each year, close to $20tn worth of traded goods are driven, shipped and flown across the world. The global value of trade in goods has tripled during the 21st century alone.

But, as the world attempts to curb its greenhouse gas emissions, its increasing interconnectedness can complicate matters.

A key debate is who should be held responsible for greenhouse gas emissions of internationally traded goods. In a globalised economy, should responsibility for emissions lie with those that produce goods? Or should it rather be accounted for by those that consume final goods and services?

In a new paper, published in Global Environmental Change, we suggest that an exclusive focus on producers or consumers falls short as a method of allocating trade-related emissions to individual countries.

Instead, we propose an accounting scheme that divides trade-related emissions among trade partners in proportion to the economic benefits they derive from these emissions.



Early next step: Add risk management to National Climate Assessment

Posted on 14 January 2021 by Guest Author

This is a re-post from Yale Climate Connections by Gary Yohe, Henry Jacoby, Richard Richels, and Benjamin Santer

Imagine a major climate change law passing the U.S. Congress unanimously? Don’t bother. It turns out that you don’t need to imagine it. Get this:

The Global Change Research Act of 1990 was passed unanimously (100-0) in the United States Senate and by voice vote in the House of Representatives. Wow.

The law instructed all relevant federal agencies to intensify their separate research activities into climate change trends, impacts, and uncertainties and to coordinate their efforts under a newly created United States Global Change Research Program (USGCRP). Congress also recognized the need to communicate to the general public the societal and natural vulnerabilities derived directly or indirectly from current or projected climate change. To do that, the law mandated that the federal research community prepare regular national climate assessments (NCAs) to be distributed to the American people every four years by the sitting President.

The first assessment (NCA1), approved and released in November of 2000, effectively began the communication process. It alerted Americans of growing threats posed by human-induced changes in local and regional climates.

Beginning around 2007, risk assessment became the accepted approach to understanding and communicating climate change impacts around the world. NCA3 in 2014 and NCA4 in 2018 therefore instructed writing teams to characterize important climate change effects in terms of the two key principles of risk: the likelihoods of climate change impacts, and their consequences as measured by dollars, lives, other public health metrics, etc.

This risk-based framing meant that national assessments should report high-risk possibilities of all sorts: high-risk circumstances that could, for example, be (1) highly likely to occur with modest to moderate consequences; or (2) more-likely-than-not to occur with more serious consequences; and/or (3) unlikely to occur but with enormous and sometimes calamitous consequences.



Skeptical Science New Research for Week #2, 2021

Posted on 13 January 2021 by doug_bostrom

Tide of tidal data rises 

Having cast our own fate to include rising sea level, there's a degree of urgency in learning the history of mean sea level in any given spot, beyond idle curiosity. Sea level rise (SLR) isn't equal from one place to another and even at a particular coordinate is not monotonic, isn't smoothly continuous. Particularly for adaptation and resilience planning purposes it's useful to know the full history of sea level anywhere that something or someone is at risk from rising waters. 



How we work: Getting input from scientists

Posted on 12 January 2021 by BaerbelW , David Kirtley, John Mason, jg

Over the years, we've published many rebuttals, blog posts and graphics which came about due to direct interactions with the scientists actually carrying out the underlying research or being knowledgable about a topic in general. We'll highlight some of these interactions in this blog post. We'll start with two memorable exchanges with scientists Bärbel Winkler had when putting together two blog posts about research involving seals and birds, followed by other examples about ice cores, the jetstream and the history of climate science originally written by David Kirtley and John Mason and with illustrations created by John Garrett (jg).


Researchers tagging seals

During a presentation by Prof. Dr. Martin Wikelski (Max Planck Institute for Ornithology) at a conservation conference in January 2014 Bärbel heard something about climate research involving seals for the very first time. This sounded intruiging so she sent an email to Dr. Wikelski after the conference to ask for some additional details and he promptly replied with some published papers and contact information for the researchers actually working with the seals and the data they collected. Next, she contacted Prof. Dan Costa at the University of California Santa Cruz (UCSC) and his research team who were also very forthcoming with providing information, pictures and helpful feedback for the blog post "Seal of approval - How marine mammals provide important climate data" published in June 2014. This was Bärbel's first experience contacting researchers about one of their projects and it couldn't have been more positve!

Tagging a sealTagging a southern elephant seal (photo: Dan Costa - NMFS 87-1851-03)



Reviewing the horrid global 2020 wildfire season

Posted on 11 January 2021 by Guest Author

This is a re-post from Yale Climate Connections by Jeff Masters, PhD

The 2020 global wildfire season brought extreme fire activity to the western U.S., Australia, the Arctic, and Brazil, making it the fifth most expensive year for wildfire losses on record.

The year began with an unprecedented fire event in Australia, where wildfire smoke in the capital city of Canberra registered the worst air quality readings in the world on January 1. The Canberra Times reported that smoke billowing through the city exceeded the “hazardous” threshold by over a factor of 20.

Australia in 2019 had experienced its hottest and driest year on record, which helped drive fires that burned an astonishing 46 million acres – an area larger than the state of Florida – during the 2019-2020 fire season. While larger areas of the nation have burnt in at least four previous years, the 2019-2020 wildfires affected a larger share of forested and populated areas than previous fires did, resulting in far more impacts to people and ecosystems.

According to insurance broker Aon, the 2019-2020 wildfires were Australia’s most expensive on record, with damages of $4.5 billion (including physical damage and impacts to timber, agriculture, infrastructure, and direct business interruption). EM-DAT, the international disaster database, lists the “Black Saturday” wildfire season of 2009 as Australia’s second-most expensive wildfire season, with $1.6 billion (2020 dollars) in damages.

Figure 1Figure 1. This incredibly intense New Year’s Eve wildfire event in New South Wales, Australia, on December 31, 2019, created passive pyrocumulus clouds that injected record amounts of ash into the stratosphere. (Image credit: Pierre Markuse)



2021 SkS Weekly Climate Change & Global Warming Digest #02

Posted on 10 January 2021 by John Hartz

Story of the Week... Toon of the Week... Coming Soon on SkS... Poster of the Week... SkS Week in Review... 

Story of the Week...

Coming attraction: IPCC's upcoming major climate assessment

Look for more emphasis on 'solutions,' efforts by cities, climate equity ... and outlook for emissions cuts in a hoped-for global economic recovery from pandemic. 

 John Kerry Signs Climate Agreement

John Kerry – then U.S. Secretary of State, and now set to be the U.S. Special Presidential Envoy for Climate – signs the Paris Agreement on Climate Change on April 22, 2016, at UN headquarters, with his granddaughter in tow. The upcoming IPCC Sixth Assessment Report will be released ahead of the 2023 deadline for nations to update the emission cuts they pledged under the agreement. (Photo credit: United Nations / Flickr

Despite the speed bump posed by the COVID-19 pandemic, the Intergovernmental Panel on Climate Change is rolling toward completion of its Sixth Assessment Report, the latest in a series that began in 1990.

IPCC’s assessments, produced by many hundreds of scientists volunteering countless hours, have long been the world’s most definitive statements on human-induced climate change from fossil fuel use. Rather than carrying out its own research, the IPCC crafts its consensus assessment reports based on the vast array of peer-reviewed work in science journals. The draft reports are scrutinized by experts and officials in UN-member governments before they become final.

It’s too soon to know exactly what the authors will conclude in the Sixth Assessment Report (AR6), to be released in 2021-22, but the chapter outlines suggest a more interwoven look at how society is affected by, and responds to, the climate crisis.

The report could also end up tipping its hat toward a narrowing range of potential outcomes, as reflected in recent key papers and greenhouse-gas emission trends. If the most dire scenarios of past reports are a bit less likely than it seemed a decade ago, some of the tamer scenarios also might be increasingly out of reach.

Nations will draw on the new assessment as they prepare to revise their emission goals in the Paris Agreement’s first five-year stocktake, set for 2023.

Click here to access the entire article as originally posted on the Yale Climate Connections website.

Coming attraction: IPCC's upcoming major climate assessment by Bob Henson, Article, Yale Climate Connections, Jan 6, 2021



2021 SkS Weekly Climate Change & Global Warming News Roundup #2

Posted on 9 January 2021 by John Hartz

A chronological listing of news articles linked to on the Skeptical Science Facebook Page during the past week: Sun, Jan 3, 2021 through Sat, Jan 9, 2021

Editor's Choice

After the Insurrection: Accountability, Reform, and the Science of Democracy

Trump  & Sen Hawley

The poisonous lies and enablers of sedition--including Senator Hawley, pictured here with the president--will remain even after Trump leaves office. The new president and Congress have the chance to begin to right many wrongs. But they need our strength to hold them to task--and to hold them accountable for resetting the norms, actions, and policies of our government. Photo: Charlie Riedel/AP

I have led the Center for Science and Democracy at the Union of Concerned Scientists since 2012 when it was formed. We came into being because UCS believes that science and scientists have a critical role to play in our society and because of the urgent needs to strive for a “healthy planet and a safer world.”

When we are witness to the events of this week—and indeed the last four years—it is impossible to avoid the conclusion that those who support the role of science in American constitutional democracy must also defend and strengthen that democracy in order to achieve our aims. We, as the UCS community, can not stand by as our very democracy is attacked by President Trump, his henchmen in Congress, and his rioters attacking the Capitol.

There are many organizations working on civil rights and democracy reform. What UCS brings to the battle is a connection to the science of democracy, elections, and fair representation—and the critical importance of fair voting and broader representation to achieving virtually all of the policy reforms UCS advocates for across our issue areas. Our supporters, based on science as well as the urgent need for civil rights, advocate for the changes we need as a country to combat disinformation. Together we fight to institute policies that secure fairer representation, safer elections even in times of pandemic, and policies that serve the interests and needs of all of the public.

Make no mistake that we, as the voice for science, have a unique role and responsibility in the movement for a healthy democracy and fair representation. Just as science is needed to ensure that policies are effective, a healthy democracy is needed to ensure that they are fair—and the success of both hinge on people’s right to vote and fair representation. Simply put, we cannot realize the role of science and evidence for achieving a healthier and safer society until we can ensure our government is serving and accountable to the people. 

After the Insurrection: Accountability, Reform, and the Science of Democracy by Andrew Rosenberg, Blogs, Union of Concerned Scientists, Jan 8, 2021



Guest post: How human activity threatens the world’s carbon-rich peatlands

Posted on 8 January 2021 by Guest Author

This article, guest authored by Prof. Angela Gallego-Sala & Dr. Julie Loisel, was originally published on the Carbon Brief website on Dec 21, 2020. It is reposted below in its entirety. Click here to access the original article and comments.



Peatlands are ecosystems unlike any other. Perpetually saturated, their wetland soils are inhospitable to many plants and trees, yet they are rich in carbon.

But the world’s peatlands are under threat on multiple fronts. From a warming climate and rising sea levels through to land-use change and wildfires, disturbing peatland ecosystems risks releasing their long-held carbon into the atmosphere. 

In our recent paper, published in Nature Climate Change, we review the scientific literature and survey experts to explore the biggest risks to global peatlands and their potential impacts during this century and beyond.



Covid-19 and Climate Change Will Remain Inextricably Linked, Thanks to the Parallels (and the Denial)

Posted on 7 January 2021 by Guest Author

This is a re-post from Inside Climate News by Ilana Cohen. Inside Climate News is a nonprofit, independent news organization that covers climate, energy and the environment. Sign up for the ICN newsletter here.

Whether or not people accept the science on Covid-19 and climate change, both global crises will have lasting impacts on health and quality of life, especially for the diverse and low-income communities they’ve already hit hardest.

The Covid-19 pandemic acted “almost like a heat-seeking missile,” homing in on the same communities most vulnerable to the effects of a warming world, said Robert Bullard, an author and professor at Texas Southern University who is widely known as “the Father of Environmental Justice.” 

Even worse, Bullard said, the pandemic represented only the “tip of the iceberg” for what such communities could face.

In many ways, the United States’ struggle to control Covid-19 has painted a picture, part hopeful and part harrowing, of how the climate crisis might play out in the decades to come. 

Many climate activists and progressives hoped—at least at initially—that the death and illness associated with a worldwide pandemic would make it easier for people to take distant climate threats more seriously.

It didn’t take all that much imagination. The parallels were everywhere.



Skeptical Science New Research for Week #1, 2021

Posted on 6 January 2021 by doug_bostrom

Melted ice of the past answers question today?

Kate Ashley and a large crew of coauthors wind back the clock to look at Antarctic sea ice behavior in times gone by, in Mid-Holocene Antarctic sea-ice increase driven by marine ice sheet retreatFor armchair scientists following the Antarctic sea ice situation, something jumps out in this work. Antarctic sea ice enthusiasts know that science has struggled to fully and crisply explain why sea ice around the Antarctic has generally maintained or even expanded  extent, during austral winter. Hence the penultimate sentence of this article's abstract grabs our attention:

Over recent decades Antarctic sea-ice extent has increased, alongside widespread ice shelf thinning and freshening of waters along the Antarctic margin. In contrast, Earth system models generally simulate a decrease in sea ice. Circulation of water masses beneath large-cavity ice shelves is not included in current Earth System models and may be a driver of this phenomena. We examine a Holocene sediment core off East Antarctica that records the Neoglacial transition, the last major baseline shift of Antarctic sea ice, and part of a late-Holocene global cooling trend. We provide a multi-proxy record of Holocene glacial meltwater input, sediment transport, and sea-ice variability. Our record, supported by high-resolution ocean modelling, shows that a rapid Antarctic sea-ice increase during the mid-Holocene ( 4.5 ka) occurred against a backdrop of increasing glacial meltwater input and gradual climate warming. We suggest that mid-Holocene ice shelf cavity expansion led to cooling of surface waters and sea-ice growth that slowed basal ice shelf melting. Incorporating this feedback mechanism into global climate models will be important for future projections of Antarctic changes.

Given emerging information on Antarctic ice shelf basal cavities in the present time, the authors offer a tantalizing proposition. We can hope that vigorous follow-up is the result. Ashley et al is open access and free to read. 

102 Articles 

Observations of climate change, effects

Anthropogenic Greenhouse Gas and Aerosol Contributions to Extreme Temperature Changes during 1951–2015

Attribution of Extreme Precipitation with Updated Observations and CMIP6 Simulations
Open Access pdf DOI: 10.1175/jcli-d-19-1017.1

Revisiting climatic features in the Alaskan Arctic using newly collected data
DOI: 10.1007/s00704-020-03495-8

Increased cyclone destruction potential in the Southern Indian Ocean
Open Access pdf DOI: 10.1088/1748-9326/abceed

The Relative Contributions of Temperature and Moisture to Heat Stress Changes under Warming

Uncertainty in Forced and Natural Arctic Solar Absorption Variations in CMIP6 Models
DOI: 10.1175/jcli-d-20-0244.1

Increasing cryospheric hazards in a warming climate
DOI: 10.1016/j.earscirev.2020.103500

Disentangling dynamical and thermodynamical contributions to the record-breaking heatwave over Central Europe in June 2019
DOI: 10.1016/j.atmosres.2020.105446

Influence of Northern Hemispheric Winter Warming on the Pacific Storm Track
Open Access pdf DOI: 10.1007/s00382-020-05544-4

Trends, variability, and teleconnections of long-term rainfall in the Terai region of India
DOI: 10.1007/s00704-020-03421-y

The differing role of weather systems in southern Australian rainfall between 1979–1996 and 1997–2015
Open Access pdf DOI: 10.1007/s00382-020-05588-6

Forest effects on runoff under climate change in the Upper Dongjiang River Basin: insights from annual to intra-annual scales
Open Access DOI: 10.1088/1748-9326/abd066

Instrumentation & observational methods of climate change, effects



Is Climate Action... Winning..?

Posted on 5 January 2021 by Guest Author

What do governments' announcements mean for climate change? And is this just wishful thinking, or are we finally beginning to change the trajectory of global warming?

Support ClimateAdam on patreon:



Climate Change: The Science and Global Impact - a MOOC presented by Michael Mann

Posted on 4 January 2021 by BaerbelW

The next run of our own Massive Open Online Course (MOOC) "Denial101x - Making sense of climate science denial" will start on February 9, so is still a couple of weeks away. If you are looking for another climate-related MOOC to take in the meantime - or would like to recommend to family members, friends or colleagues - check out this one which is also provided via edX:

Climate Change: The Science and Global Impact

It's offered by SDG Academy as a self-paced course with Dr. Michael E. Mann as the sole lecturer who helps you to understand the science behind global warming in order to avoid the most damaging and irreversible climate change impacts on people and planet.

From the MOOC's description on edX

Climate change is arguably the greatest challenge of our time. Human activity has already warmed the planet by one degree Celsius relative to pre-industrial times, and we are feeling the effects through record heat waves, droughts, wildfires and flooding. If we continue to burn fossil fuels at the current rate, the planet will reach two degrees of warming by 2050—the threshold that many scientists have identified as a dangerous tipping point. What is the science behind these projections?

Join climate science expert Michael Mann to learn about the basic scientific principles behind climate change and global warming. We need to understand the science in order to solve the broader environmental, societal and economic changes that climate change is bringing.



2021 SkS Weekly Climate Change & Global Warming Digest #1

Posted on 3 January 2021 by John Hartz

Story of the Week... Toon of the Week... SkS in the News... Coming Soon on SkS... Poster of the Week... SkS Week in Review...

Story of the Week...

Many Scientists Now Say Global Warming Could Stop Relatively Quickly After Emissions Go to Zero

That’s one of several recent conclusions about climate change that came more sharply into focus in 2020.

[Editor's note: The following is a repost of the final section of Berwyn's article]

Making it Stop

Some scientists punctuate their alarming warmings with hopeful messages because they know that the worst possible outcome is avoidable. 

Recent research shows that stopping greenhouse gas emissions will break the vicious cycle of warming temperatures, melting ice, wildfires and rising sea levels faster than expected just a few years ago.

There is less warming in the pipeline than we thought, said Imperial College (London) climate scientist Joeri Rogelj, a lead author of the next major climate assessment from the Intergovernmental Panel on Climate Change

“It is our best understanding that, if we bring down CO2 to net zero, the warming will level off. The climate will stabilize within a decade or two,” he said. “There will be very little to no additional warming. Our best estimate is zero.”

The widespread idea that decades, or even centuries, of additional warming are already baked into the system, as suggested by previous IPCC reports, were based on an “unfortunate misunderstanding of experiments done with climate models that never assumed zero emissions.” 

Those models assumed that concentrations of greenhouse gases in the atmosphere would remain constant, that it would take centuries before they decline, said Penn State climate scientist Michael Mann, who discussed the shifting consensus last October during a segment of 60 Minutes on CBS.

The idea that global warming could stop relatively quickly after emissions go to zero was described as a “game-changing new scientific understanding” by Covering Climate Now, a collaboration of news organizations covering climate.

“This really is true,” he said. “It’s a dramatic change in the paradigm that has been lost on many who cover this issue, perhaps because it hasn’t been well explained by the scientific community. It’s an important development that is still under appreciated.” "It’s definitely the scientific consensus now that warming stabilizes quickly, within 10 years, of emissions going to zero,” he said. 

Many Scientists Now Say Global Warming Could Stop Relatively Quickly After Emissions Go to Zero by Bob Berwyn, Science, InsideClimate News, Jan 3, 2020



2021 SkS Weekly Climate Change & Global Warming News Roundup #1

Posted on 2 January 2021 by John Hartz

A chronological listing of news articles linked to on the Skeptical Science Facebook Page during the past week: Sun, Dec 27, 2020 through Sat, Jan 2, 2021

Editor's Choice

7 Graphics That Show Why the Arctic Is in Trouble

Arctic Sea Ice NSIDC

Arctic Sea Ice: NSIDC

It’s no secret that the Arctic is in trouble. And while the worrying state of the ice in the region has made numerous headlines this year, they’re just the latest twists and turns in a long-term trend.

One of the best gauges for putting what’s happening in the region into perspective is the National Oceanic and Atmospheric Administration’s Arctic Report Card, a compilation of environmental observations and analyses that the agency has been producing annually for 15 years. It was released earlier this month, providing an in-depth look at the Arctic’s struggles as the climate crisis reshapes the region. But if you’re more of a visual person, NOAA made these neat—although worrying—graphics to help get a handle on what’s happened this past year and how it fits into the bigger picture.

Join us as we take a dive into a series of graphics that highlight key findings of the Arctic Report Card, and explain why you should care about what happens up there.

Click here to access the entire article and slideshow as originally published on the Gizmodo website. 

7 Graphics That Show Why the Arctic Is in Trouble by Jody Serrano, Slideshow, Gizmodo, Dec 31, 2020



Analysis: Why the new Met Office temperature record shows faster warming since 1970s

Posted on 1 January 2021 by Guest Author

This article, authored by Zeke Hausfather, was originally published on the Carbon Brief website on Dec 17, 2020. It is reposted below in its entirety. Click here to access the original article and comments.

 Sunset in Kenya

Sunset in Kenya

The first major update of the UK Met Office’s global temperature dataset in eight years moves it from one of the slowest warming records to the fastest.

A number of different research groups around the world provide estimates of global surface temperatures. They differ based on their starting year, the corrections they make to changing measurement techniques, and how they deal with gaps between measurement locations. However, all show similar levels of warming over the past 150 years: between 1C and 1.2C.

One of these records, HadCRUT4 – produced in a collaboration between the Met Office Hadley Centre and the Climatic Research Unit at the University of East Anglia – showed the lowest warming of the bunch, at least 0.1C below most of the others. Its newly published successor – HadCRUT5 – corrects some remaining issues in the old record and brings it more closely in line with other groups.

The step-change is due to two major updates in the Hadley record. First, the new record includes an update in the sea surface temperature (SST) record it uses – from HadSST3 to HadSST4. Among other revisions, this new SST dataset corrected some issues in ship-based measurements by using more reliable data from buoys, increasing warming by around 0.1C in recent years.

Second, the new HadCRUT5 dataset uses statistical analysis to fill in gaps in data collection in the Arctic and other regions that were not covered in HadCRUT4. As the Arctic is the fastest warming region of the world, its more complete inclusion also increases global temperatures by up to an additional 0.1C.

HadCRUT5 is currently only available for the period 1850-2018, but it will be updated to the present day (and on an ongoing monthly basis) at some point in early 2021.

The changes made to HadCRUT5 will increase the likelihood that 2020 will be the warmest year on record in that dataset (HadCRUT4 is exceedingly unlikely to show a new record in 2020), though it is too soon to know for sure until it is updated for the full year.



Skeptical Science New Research for Week #52, 2020

Posted on 30 December 2020 by doug_bostrom

Happy Holidays, Crew!

Given the smoothing effect of the publication pipeline, it's safe to say that publisher staff took a full holiday this month, as reflected in this edition's paltry collection of 54 articles, around 1/2 of our normal bill of lading.

Post-AGW research

After viewing a few dozen editions of New Research  something becomes strikingly apparent: despite die-hard deniers still banging on with their monologue "debate" about climate change, legitimate scientific practice has long moved on. Climate change is woven into the fabric of ongoing investigation of a myriad of phenomena. The fact of climate change has been absorbed and is added to our inventory of reliable explanatory power. Many researchers are deeply into knock-on effects of an already-changed climate while others refer to the fact of change tangentially. 

In this week's "Observations..." section is an exemplary publication helping to illustrate where the scientific community stands, Atmospheric driving mechanisms of extreme precipitation events in July of 2017 and 2018 in western Japan (open access). Authors Nayak & Takemi explain how a pair of extreme meteorological events came to pass, focusing on atmospheric dynamics temporally immediate to the systems in question. Their analysis is not about climate change - the topic of their paper is "just" weather - but climate change is what made the weather they examine possible. This attribution is barely remarked in the abstract, because for specialists in the field it's tacitly understood, a given. In the body of the paper, the underlying climate change drivers of the specific effects scrutinized by Nayak & Takemi are crisply dealt with in a list of references. That's it. There's no "debate," no waffling, nothing serious to discuss about the ultimate energy source amplifying this weather.

If deniers bothered to stay current with scientific research having even a remote degree of connection to climate, they'd surely realize they're still standing at the station long after the knowledge train has departed. Where do they get their information? 

54 Articles

Physical science of climate change, effects

A global study of hygroscopicity-driven light scattering enhancement in the context of other in-situ aerosol optical properties
Open Access DOI: 10.5194/acp-2020-1250 (preprint)

Observations of climate change, effects

A new intermittent regime of convective ventilation threatens the Black Sea oxygenation status
Open Access pdf DOI: 10.5194/bg-17-6507-2020

Accelerated glacier mass loss in the Russian Arctic (2010–2017)
Open Access DOI: 10.5194/tc-2020-358 (preprint)

The role of sea-level changes in the evolution of coastal barriers – An example from the southwestern Baltic Sea
Open Access pdf DOI: 10.1177/0959683620981703

Ring widths of Rhododendron shrubs reveal a persistent winter warming in the central Himalaya
DOI: 10.1016/j.dendro.2020.125799

Atmospheric driving mechanisms of extreme precipitation events in July of 2017 and 2018 in western Japan
Open Access DOI: 10.1016/j.dynatmoce.2020.101186

Large-area thermal anomalies in Europe (1951–2018). Temporal and spatial patterns
DOI: 10.1016/j.atmosres.2020.105434

Evidence of asymmetric change in Diurnal Temperature Range in recent decades over different Agro‐climatic Zones of India
DOI: 10.1002/joc.6978

Assessing trends in atmospheric circulation patterns across North America
DOI: 10.1002/joc.6983



2020 in Review: an interesting year for Skeptical Science

Posted on 29 December 2020 by BaerbelW

As we wrap up a truly interesting year 2020 and prepare for 2021, here is our annual review of what our team was up to during the last 12 months, most of which have obviously been dominated by the COVID-19 pandemic. As in previous recaps, this one is divided into several sections:

Scholary publications, projects and books

Other publications and activities

Recorded talks and podcasts

Our MOOC Denial101x


Fun stuff

Website activities

Social media



Scholarly publications, projects and books

Several members of the SkS-team were lead- or co-authors of peer-reviewed papers published during 2020. Here is a list of some of them:

Past warming trend constrains future warming in CMIP6 models
Katarzyna B. Tokarska, Martin B. Stolpe, Sebastian Sippel, Erich M. Fischer, Christopher J. Smith, Flavio Lehner, Reto Knutti (2020, March). Science advances, 6(12), eaaz9549.

The story of Skeptical Science: How citizen science helped to turn a website into a go-to resource for climate science
Bärbel Winkler & John Cook (2020, May). In EGU General Assembly Conference Abstracts(p. 562).

Using the COVID-19 economic crisis to frame climate change as a secondary issue reduces mitigation support
Ullrich Ecker, Lucy Butler, John Cook, Mark Hurlstone, Tim Kurz, & Stephan Lewandowsky (2020, August).  Journal of Environmental Psychology, 70, 101464.

Structural barriers to scientific progress
Kevin Cowtan (2020, September). Acta Crystallographica Section D: Structural Biology, 76(10).
"[...] This letter was inspired by an apparently similar set of circumstances arising in two different fields. When a crystallographer started comparing climate data sets from national science agencies, the differences led rapidly to a number of insights which were not being pursued by more experienced practitioners (Cowtan & Way, 2014; Hausfather et al., 2017; Cowtan et al., 2018).[...]"

Pacific variability reconciles observed and modelled global mean temperature increase since 1950
Martin B. Stolpe, Kevin Cowtan, Iselin Medhaug & Reto Knutti (2020, October). Climate Dynamics, 1-22.



Coping with fire-scorched land more prone to mudslides

Posted on 28 December 2020 by Guest Author

This is a re-post from Yale Climate Connections by Daisy Simmons

After a fire, rain can feel like a refreshing mercy. But it also spells fresh danger in fire-struck areas made newly vulnerable to mudslides. Amidst recovering from the trauma of a wildfire, people in hillside homes across much of the western U.S., in particular, must now be ready to evacuate when threatening heavy rains appear in the forecast.

That’s because fires do more to the physical environment than level buildings and fell trees. They also alter the makeup of the soil, making it less likely it will absorb rainwater, especially during a downpour.

“The same intensity of rain can generate overland flows more than 10 times greater in areas recently burned compared to those without fire,” Arizona State University (ASU) environmental engineer Mikhail Chester said in Popular Science.

To explain why fire-scorched land is more prone to mudslides, and what communities can do about it, let’s begin with the basics.

What causes a debris flow?

On a typical hillside not recently burned, vegetation helps trap the soil in place. When rain pours down in a major storm, trees, shrubs, grasses, and leaf litter all help protect the soil from a heavy downpour, giving water more time to soak into the ground.

As much as 5 years after the raging embers have cooled, resulting mudflows can pose still more threats.

But when fire destroys that vegetation, there can be little left to keep soil and sediment from flowing down a steep hill, much less retain water there. What’s more, parched, fire-charred soil can become hydrophobic, which means it actually repels water, just as pavement does.

Wildfire burn graphic(Source: National Weather Service)



2020 SkS Weekly Climate Change & Global Warming Digest #52

Posted on 27 December 2020 by John Hartz

Story of the Week... Editorial of the Week... Toon of the Week... Graphic of the Week... Coming Soon on SkS... Climate Feedback Claim Review... SkS Week in Review... Poster of the Week...

Story of the Week...

The Resistance: In the President’s Relentless War on Climate Science, They Fought Back

The scientists' efforts were often unseen and sometimes unsuccessful. But over four years, they mounted a guerilla defense that kept pressure on the Trump Administration.


Every time the word “climate” was deleted from the name of his program at the Environmental Protection Agency, Dan Costa stuck it back in.

Chris Frey fought back in the unlikely setting of a hotel conference room, where he and 20 other members of an EPA science review panel dismissed by the Trump administration met to do their job anyway, later publishing their views in a prestigious medical journal.

And as Jeff Alson was walking out the door of the EPA in frustration after a 40-year career at the agency, he gave pep talks to the younger engineers about why they had to stay on.

“I told them what I’m going to do for you is go out and tell the truth, so that the public knows that this rollback is not being done by EPA staff, it is being done by other people in the government,” Alson said. 

These are snapshots of the resistance. Although their names are little known and their efforts often went unseen, they defied the relentless campaign President Donald Trump and his administration waged against mainstream science during the four years of his presidency—particularly the scientific consensus on climate change.

The outcome of this war is yet to be written. Trump has rolled back more than 100 environmental regulations, loosening restrictions on fossil fuel development when the science points ever more urgently to the need to stop the reliance on energy sources that produce greenhouse gas emissions. In California earlier this year, the president summarized his administration’s attitude toward scientific expertise: “I don’t think the science knows,” he said, as the state’s worst wildfire season on record raged all around him.

But the Trump administration’s drive to dismiss and deny climate science has made only partial headway. In what may be a sign of the robustness of both the science and the U.S. institutions that support it, scientists inside and outside the federal agencies fought back.

Click here to access the entire article as originally posted on the InsideClimate News website.

The Resistance: In the President’s Relentless War on Climate Science, They Fought Back by Marianne Lavelle, Science, InsideClimate News, Dec 27, 2020



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