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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?


Study: Accounting for value of nature reinforces Paris climate targets

Posted on 26 January 2021 by dana1981

This is a re-post from Yale Climate Connections

Anew study in Nature Sustainability incorporates the damages that climate change does to healthy ecosystems into standard climate-economics models. The key finding in the study by Bernardo Bastien-Olvera and Frances Moore from the University of California at Davis: The models have been underestimating the cost of climate damages to society by a factor of more than five.

Their study concludes that the most cost-effective emissions pathway results in just 1.5 degrees Celsius (2.7 degrees Fahrenheit) additional global warming by 2100, consistent with the “aspirational” objective of the 2015 Paris Climate Agreement.

Models that combine climate science and economics, called “integrated assessment models” (IAMs), are critical tools in developing and implementing climate policies and regulations. In 2010, an Obama administration governmental interagency working group used IAMs to establish the social cost of carbon – the first federal estimates of climate damage costs caused by carbon pollution. That number guides federal agencies required to consider the costs and benefits of proposed regulations.

Given the importance of the social cost of carbon to federal rulemaking, some critics have complained that the Trump EPA used what they see as creative accounting to slash the government’s estimate of the number. In one of his inauguration day Executive Orders, President Biden established a new Interagency Working Group to re-evaluate the social cost of all greenhouse gases.

IAMs often have long been criticized by those convinced they underestimate the costs of climate damages, in some cases to a degree that climate scientists consider absurd.

Perhaps the most prominent IAM is the Dynamic Integrated Climate-Economy (DICE) model, for which its creator, William Nordhaus, was awarded the 2018 Nobel Prize in Economic Sciences. Judging by DICE, the economically optimal carbon emissions pathway – that is, the pathway considered most cost-effective – would lead to a warming increase of more than 3°C (5.4°F) from pre-industrial temperatures by 2100 (under a 3% discount rate). IPCC has reported that reaching this level of further warming could likely result in severe consequences, including substantial species extinctions and very high risks of food supply instabilities.

In their Nature Sustainability study, the UC Davis researchers find that when natural capital is incorporated into the models, the emissions pathway that yields the best outcome for the global economy is more consistent with the dangerous risks posed by continued global warming described in the published climate science literature.



The SCIARA Project – Interactive Time Travel into the Climate Future

Posted on 25 January 2021 by Guest Author

This is a guest blog post by Daniel Tamberg, Potsdam, co-founder and director of SCIARA GmbH. The non-profit organisation SCIARA is developing and operating a flexible software platform for scientific simulation games that allows thousands of players to explore, design and understand possible climate futures together. Decision-makers in politics, business, society can use these games to test climate protection measures for social acceptance in advance, in order to be able to act more quickly and safely to combat global warming.

SCIARA is currently running a crowdfunding campaign to finance the next round of development and refinement after a first Minimal Viable Product (MVP) has been created in the last seven months by a team of software development professionals ten members strong.


Setting the stage

Once the evidence of what was causing the ozone hole had become clear in 1985, it only took a few years to ban the production and use of the responsible chlorofluorocarbons (CFCs) after the Montreal Protocol was signed in 1987 and entered into force on 26 August 1989. Replacing the ozone-depleting CFCs was technically easy, and users were not subjected to any significant restrictions as a result of the technological changeover.

Tackling climate change requires global interaction of many complex technical and social solutions. Central industries will be massively affected and are - in some cases - bound to die: first and foremost the fossil energy industry as well as the automotive and aircraft industries, which have provided unprecedented prosperity in the past. And the lifestyle of billions of people will need to change.

Any politician or business leader who takes early and decisive action on climate change risks losing voters, customers, investors, and supporters - see French President Macron’s experience with the Yellow Vests. Those who act too late or too hesitantly, on the other hand, become responsible for the catastrophic effects of climate change in the future.



2021 SkS Weekly Climate Change & Global Warming Digest #4

Posted on 24 January 2021 by John Hartz

Story of the Week... La Niña Update... Toon of the Week... Video of the Week... Coming Soon on SkS... Climate Feedback Article Review... SkS Week in Review... Poster of the Week...

Story of the Week...

Davos Agenda: What you need to know about saving the planet

  • 2020 showed us that action on climate change is more urgent than ever.
  • Building back better must include a focus on reaching net-zero, the energy transition and committing to circular economies and sustainable consumption.
  • The Davos Agenda will mobilize global leaders to build a healthier, more resilient planet.

A year ago at the Forum's Annual Meeting in Davos – heeding the advice of speakers including Greta ThunbergUN Secretary-General Antonio Guterres and Prince Charles – government, business and civil society committed to take more concrete action on climate change and save the planet from a hotsmoky, polluted demise.

Throughout the week, delegates watched in horror as bushfires ravaged Australia – ultimately burning more than 11 million hectares of land and killing or displacing as many as 3 billion animals. By the end of the week, a Davos press conference about a new global threat – a highly infectious virus emerging in China – showed the world that we could no longer ignore the links between the health of the planet and the health of humans, economies and societies.

From 25-29 January 2021, The Davos Agenda will bring many of those leaders together again to discuss the innovative and bold solutions needed to stem the pandemic and drive a robust recovery – with a focus on the resiliency and sustainability of our ecosystems and infrastructure.

Click here to access the complete article as originally posted on the World Economic Forum website. 

Davos Agenda: What you need to know about saving the planet by Samantha Sault, Agenda, World Economic Forum, Jan 24, 2021



2021 SkS Weekly Climate Change & Global Warming News Roundup #4

Posted on 23 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 17, 2021 through Sat, Jan 23, 2021

Editor's Choice

12 new books explore fresh approaches to act on climate change

Authors explore scientific, economic, and political avenues for climate action given 'new possibilities' in 2021.

New books on climate change in 2021


Despite a journey to this moment even more treacherous than expected, Americans now have a fresh opportunity to act, decisively, on climate change.

The authors of the many new books released in just the past few months (or scheduled to be published soon) seem to have anticipated this pivotal moment.

Their number includes a scientist, an entrepreneur, and a journalist, each of whom has published among the first calls to action on climate change: Michael Mann, Bill Gates, and Elizabeth Kolbert.

But all the authors recognize that our repeated failures to seize previous opportunities says something about our market economy, our mindsets, and our political institutions. Thus the solutions offered in these new titles are as often political as they are scientific and technical, and psychological as often as they are environmental.

Americans succeeded in making a critical change: a climate denier no longer presides over the United States. With the 12 titles listed below, Americans can now consider new possibilities – at all levels – made possible by that first change.

As always, the descriptions of the 12 titles listed below are adapted from copy provided by the publishers.

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

12 new books explore fresh approaches to act on climate change by Michael Svoboda, Ph.D., Articles, Yale Climate Connections, Jan 22, 2021



Analysis: The climate papers most featured in the media in 2020

Posted on 22 January 2021 by Guest Author

This article, guest authored by Robert Sweeney was originally published on the Carbon Brief website on Jan 13, 2021. The first part of the article is reposted below in. Click here to access the complete original article and comments posted on Carbon Brief.

The top ten climate papers 

Last year was meant to be very different. The lead up to the fifth anniversary of the Paris Agreement was marked out by many as the year for climate action. Indeed, 2020 followed a year where climate change had been propelled onto newspaper front pages by Greta Thunberg, school strikes and Extinction Rebellion.

But, as with many aspects of 2020, the Covid-19 pandemic soon took centre stage.

As normal life was turned upside down, newspaper headlines and social media conversations were dominated by lockdowns, vaccines and infection rates.

Yet there was still space to report on climate change. And thousands of newly published peer-reviewed climate papers vied for media attention throughout the year.

These studies were covered around the world in news articles and blogs. They were also shared on social media platforms, such as Twitter, Facebook and LinkedIn.

Tracking all these “mentions” was Altmetric, an organisation that scores and ranks papers according to the attention they receive. (Full details of how the Altmetric scoring system works can be found in an earlier article.)

Using Altmetric data for 2020, Carbon Brief has compiled its annual list of the 25 most talked-about climate change-related papers that were published the previous year. The infographic above shows which ones made it into the Top 10, while the chart at the end of the piece shows which journals feature most frequently in the Top 25.



What Biden and Democratic Senate can do on climate in their first 100 days

Posted on 21 January 2021 by dana1981

This is a re-post from Yale Climate Connections

Democrats now control the White House, Senate, and House of Representatives for the first time in a decade, albeit with razor thin Congressional majorities. The last time, in the 111th Congress (2009-2011), House Democrats passed a carbon cap and trade bill, but it died a quiet death in the Senate after failing to muster the 60 votes needed to overcome a filibuster threat.

Since then, neither the Senate nor the House has come close to passing a major climate bill despite strong majority support among Americans for climate action. Which is not to say that there’s real potential for legislative action on a complete original “Green New Deal.”

Still, things are likely to change with the newly seated Democratic majorities. They will likely still have to contend with the same filibuster threat that felled their climate bill in 2009. President Biden has proposed an ambitious climate plan, but his administration’s progress on legislation will be encumbered from the start by the need to undo the Trump administration environmental regulatory rollbacks.

It’s a long-held Washington tradition to consider a first-100-days-in-office marker, something of a throwback to gentler times when newly seated presidents were awarded a “honeymoon” period. No telling what lies ahead given the current political mayhem and the context of a global pandemic, an impeachment trial, social inequity unrest, slowing economic indicators, and the aftermath of the January 6 insurrection and breach of the U.S. Capitol.

That said, an outlook for the Democratically controlled White House and Congress on climate change in Biden’s first 100 days:



Skeptical Science New Research for Week #3, 2021

Posted on 20 January 2021 by doug_bostrom

Weather reporting turns into climate recording

Leading a quartet of researchers, Dr. Chunlüe Zhou produces a tour de force of improved and more productive data exploitation in the paper A New Approach to Homogenize Global Subdaily Radiosonde Temperature Data from 1958 to 2018.

Due to operational constraints, instrument characteristics and the limited objectives of the original collection process, our enormous trove of meteorological radiosonde information is notoriously difficult to deal with. This data tantalizes researchers because of high potential for investigating matters on a much longer time scale and for purposes other than the synoptic weather reports these instruments and their observational records originally supported. 

One such matter is that of tropospheric warming, a key expected signature of our warming our climate due to CO2 emissions. Although we have reasonable confidence that this warming is indeed happening, by teasing useful signal from noisy radiosonde data challenged by various "wild" variables Zhou et al appear to confirm this finding again, in a way that is significantly helpful and supported by a thoroughly circumspect treatment. Their conclusion on the tropospheric record emerging after the fog of accidental factors has been dissipated is quite confident:

"The homogenized data clearly show a warming maximum around 300 hPa over 30°S–30°N, consistent with model simulations, in contrast to the raw data." 

Later in the paper, the authors elaborate:

The homogenized data show enhanced warming trends in the middle-to-lower troposphere over central and East Asia and northern Africa, but do not show the spurious cooling around 300 hPa over northern China and Mongolia seen in the raw data and many reanalysis products. A tropospheric warming maximum around 300 hPa over 30°S–30°N is absent in the raw data, but is present in the homogenized data. Thus, the lack of such a tropospheric warming maximum in previous analyses of radiosonde data (Thorne et al. 2011bMitchell et al. 2013) is likely due to the impact of the inhomogeneities in these data. Our homogenized data confirm the existence of such a tropospheric warming maximum present in some homogenized datasets, reanalysis products, and climate models with increased GHGs (Santer et al. 2005Trenberth and Smith 2006Thorne et al. 2011bHaimberger et al. 2012Mitchell et al. 2013Santer et al. 2017). The homogenization generally reduces the variance and leads to more consistent latitudinal variations of the variance in daily temperatures, especially for Indian stations.

A solid step forward in cementing our understanding of tropospheric warming. As well, the team's innovative approach offers some general lessons and promising improvements in methods for handling other such cases of what seems like unpromising data quality. As with other papers we admire, in laying the groundwork for their own effort the authors present a mini-education on prior work in this area, making this publication even more rewarding. Open access, free to read. 

63 Articles

Physical science of climate change, effects

Variability of the surface energy balance in permafrost-underlain boreal forest
Open Access pdf DOI: 10.5194/bg-18-343-2021

Observations of climate change, effects

Constraining human contributions to observed warming since the pre-industrial period
DOI: 10.1038/s41558-020-00965-9

Detectable Intensification of Hourly and Daily Scale Precipitation Extremes across Eastern China
DOI: 10.1175/jcli-d-20-0462.1

Response of downstream lakes to Aru glacier collapses on the western Tibetan Plateau
Open Access pdf DOI: 10.5194/tc-15-199-2021

Debris cover and the thinning of Kennicott Glacier, Alaska: in situ measurements, automated ice cliff delineation and distributed melt estimates
Open Access pdf DOI: 10.5194/tc-15-265-2021

Winter Arctic Amplification at the synoptic timescale, 1979–2018, its regional variation and response to tropical and extratropical variability
Open Access pdf DOI: 10.1007/s00382-020-05485-y

Changes in the equatorial mode of the Tropical Atlantic in terms of the Bjerknes Feedback Index
DOI: 10.1007/s00382-021-05627-w

Drivers of soil salinity and their correlation with climate change
DOI: 10.1016/j.cosust.2020.10.015



Gillett et al. (2021) global warming attribution study

Posted on 19 January 2021 by dana1981

The Human vs. Natural Contributions to Global Warming chart on the Skeptical Science Graphics Page has been updated to include the study discussed below

A new study published in Nature Climate Change, Gillett et al. (2021), is the latest in a long line of 'detection and attribution' studies published over the past 20-plus years that have sought to quantify the factors responsible for the rise in average global surface temperatures.

Gillett et al. used Detection and Attribution Model Intercomparison Project simulations from 13 Coupled Model Intercomparison Project Phase 6 (CMIP6) models.  The authors note that the CMIP6 historical simulations "show very little net anthropogenic warming before the 1960s. This contrasts with the CMIP5 historical simulations, which showed on average approximately 0.2°C warming by the mid-twentieth century."

To determine the attribution of the observed global surface warming of 1.1°C between the late 19th Century and the past decade, the authors performed a variant of linear regression – an optimal detection analysis using a regularized optimal fingerprinting algorithm. They conclude:

"anthropogenic forcings caused 0.9 to 1.3°C of warming in global mean near-surface air temperature in 2010–2019 relative to 1850–1900, compared with an observed warming of 1.1°C. Greenhouse gases and aerosols contributed changes of 1.2 to 1.9°C and −0.7 to −0.1°C, respectively, and natural forcings contributed negligibly. These results demonstrate the substantial human influence on climate so far and the urgency of action needed to meet the Paris Agreement goals."

In short, humans are responsible for close to 100% of global surface warming over the past 150 years.  Specifically, based on their central attribution estimates, greenhouse gases are responsible for about 1.54°C (135%) of the warming, offset by 0.44°C cooling from aerosols (-38%), plus around 0.03°C warming from natural effects (3%).  The Gillett et al. (2021) results are illustrated by the yellow bars in the charts below (note that they didn't break out the various [solar/volcanic/ENSO] natural factors in this study, as some others have).

100-150 year gw attribution

Factors attributed to causing average global surface warming since the late 19th Century by various studies, including Tett et al. 2000 (T00, dark blue), Meehl et al. 2004 (M04, red), Stone et al. 2007 (S07, light green), Lean and Rind 2008 (LR08, purple), Huber and Knutti 2011 (HK11, light blue), Gillett et al. 2012 (G12, orange), Wigley and Santer 2012 (WG12, dark green), and Gillett et al. 2021 (G21, yellow).  

Looking at the warming since the mid-20th Century (close to 0.9°C), we see a similar story: warming from greenhouse gases of about 1.1°C (125%), offset by around 0.2°C cooling from aerosols (-25%), and essentially no net temperature influence from natural factors.

50-75 year gw attribution

Factors attributed to causing average global surface warming since the mid-20th Century by various studies, including Tett et al. 2000 (T00, dark blue), Meehl et al. 2004 (M04, red), Stone et al. 2007 (S07, green), Lean and Rind 2008 (LR08, purple), Huber and Knutti 2011 (HK11, light blue), Gillett et al. 2012 (G12, orange), Wigley and Santer 2012 (WG12, dark green), Jones et al. 2013 (J13, pink), IPCC AR5 (IPCC, light green), Ribes et al. 2016 (R16, dark blue), and Gillett et al. 2021 (G21, yellow). 

The studies paint a consistent picture – human fossil fuel pollution is responsible for all of the global warming since 1950, and if Gillett et al. (2021) are correct, potentially all of the warming since the Industrial Revolution.



Getting involved with Climate Science via crowdfunding and crowdsourcing

Posted on 18 January 2021 by BaerbelW

This article was originally published in December 2016 and was updated on January 6 2021 to mention the short term crowdfunding project SCIARA as well as the new crowdsourcing project Old Weather - WW2.

At a guess, many of you reading this post are already making good personal choices to help mitigate climate change. Some of you would perhaps like to do more. So, here are some suggestions where you can get actively involved either via crowdfunding, where you make a monetary donation or via crowdsourcing, where you donate your or your computer's time to sift through different sets of data.

This post is divided into three sections:

Ongoing crowdfunding - sites and groups listed here are continously looking for donations

Shortterm crowdfunding - these are projects with a target amount and a set deadline

Crowdsourcing - projects looking for your (or your computer's) time

Ongoing crowdfunding

Climate Science Legal Defense Fund (CSLDF)

Logo-CSLDF The Climate Science Legal Defense Fund was established to make sure that legal actions are not viewed as an attack against one scientist or institution, but as attacks against the scientific endeavor as a whole. As well. the CSLDF protects individual scientists facing unfair legal attacks by organized groups. Given the current climate - pun most definitely intended - in the U.S. the CSLDF's work is unfortunately becoming ever more important. Link to donation page

Dark Snow Project

Jason Box's and Peter Sinclair's The Dark Snow Project gathers ‘hard numbers’ from the Arctic to quantify the distant snow/ice melting impact of industrial and wildfire black carbon soot; mineral dust; and microbes, each melt factor having some human driven enhancement. Link to donation page LogoDarkSnow

The Australian Climate Council

LogoClimateCouncil After thousands of Australians chipped in to Australia's biggest crowd-funding campaign, the abolished Climate Commission has relaunched as the new, independent Climate Council. We exist to provide independent, authoritative climate change information to the Australian public. Why? Because our response to climate change should be based on the best science available. Link to donation page

Citizens’ Climate Education (CCE)

Your donation to Citizens’ Climate Education will train ordinary citizens to promote fair, effective, and non-partisan climate change solutions. Citizens’ Climate Education’s volunteers understand that we owe it to tomorrow’s generations to face our climate challenges today. These informed, respectful citizens work to build a clean and prosperous future, leading elected officials towards solutions that reduce carbon pollution, create jobs, and strengthen the American economy. Link to donation page Logo-CCE

Real Skeptic Blog

Logo-RS The goal of Real Skeptic is to look at claims about science and investigate what the scientific literature has to say about it. Since the official start of Real Sceptic a wide array of articles about skepticism were written for this website. There’s a heavy emphasis on the accuracy of the articles published and the usage of high quality sources. Link to Patreon page

Inside Climate News

InsideClimate News is an essential, global voice that exposes the truth about the climate crisis. We connect the dots to those responsible, so that you can hold them accountable. As we enter our 10th year, we’re launching The InsideClimate Circle to ensure that our award-winning nonprofit news organization remains fiercely independent and courageously persistent. Link to membership page ICN-Log


Logo-ClimateAdam Adam Levy is a doctor in atmospheric physics from the University of Oxford. During his research he saw the huge gap between what we know about climate change and how we talk about it. So he created the ClimateAdam channel dedicated to explaining climate change in playful and engaging ways: everything from the crucial science to the actions we can all take. In order to grow his channel, he set up a Patreon project.

Just have aThink

Dave Borlace has been conscious of environmental issues since studying for a BSc in Technology with the Open University back in the late 1990s. In early 2017 Dave set off on a quest to create climate communication videos that aim to decode the sometimes overwhelmingly complicated and confusing scientific information around climate change and explain the concepts in the sort of plain English that he, and hopefully you, can understand. As well as looking at the causes and consequences of climate change, Dave also presents news of the technological breakthroughs that may help us avoid, or at least mitigate, the worst of those consequences. To support this work Dave has now set up a Patreon page. ICN-Log



2021 SkS Weekly Climate Change & Global Warming Digest #3

Posted on 17 January 2021 by John Hartz

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

Story of the Week...

Step up climate change adaptation or face serious human and economic damage – UN report

  • Almost three-quarters of nations have some adaptation plans in place, but financing and implementation fall far short of what is needed
  • Annual adaptation costs in developing countries are estimated at USD 70 billion. This figure is expected to reach USD 140-300 billion in 2030 and USD 280-500 billion in 2050. 
  • Nature-based solutions, critical for adaptation, need to receive more attention

Nairobi, 14 January 2021 – As temperatures rise and climate change impacts intensify, nations must urgently step up action to adapt to the new climate reality or face serious costs, damages and losses, a new UN Environment Programme (UNEP) report finds.

Adaptation – reducing countries’ and communities’ vulnerability to climate change by increasing their ability to absorb impacts – is a key pillar of the Paris Agreement on Climate Change. The agreement requires its signatories to implement adaptation measures through national plans, climate information systems, early warning, protective measures and investments in a green future.

The UNEP Adaptation Gap Report 2020 finds that while nations have advanced in planning, huge gaps remain in finance for developing countries and bringing adaptation projects to the stage where they bring real protection against climate impacts such as droughts, floods and sea-level rise.



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.



The Consensus Project Website


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