This is both my personal learning project and my contribution in the struggle to confront the ongoing Republican/ libertarian assault on rational science and constructive learning, as manifested in their malicious strategic Attacks on Science ~ A collection of articles, scientific resources, plus my own essays and indepth critique of various presentations from unidirectional-skeptics ~ Hopefully a resource for the busy, yet discerning, student who's concerned about the health of our Earth
Seems to me this is important information to get out there, so I will take advantage of Daily Climate's CC license and repost most of Peter Dykistra's opinion piece in the DailyClimate and encourage you to help inform others. It's another example of how the Republican PR machine is utterly dependent on misrepresenting science and other facts of record. Their obstinate refusal to listen to serious experts and to learn about the issues divorced from their political self-interest will guarantee all our kids a bleak difficult future. But hoping for some sober objectivity and enlightened self-interest seems like asking the impossible these days. Here we are once again faced with a glaring example of what oil company lap dogs these Republican Representatives are. All they seem to know is self-interest. So tragic.
... The effort to cast Exxon as victim of a cabal between state Attorneys General, environmentalists, and other ne’er-do-wells followed reports by journalists from InsideClimate News, the Los Angeles Times, and the Columbia Graduate School of Journalism. They uncovered a howlingly hypocritical contrast between Exxon’s longtime internal embrace of climate science and its external support for climate denial.
Decades ago, Exxon began to ignore its own scientists’ warnings on the prospects for global disruption from climate change, opting instead to focus on climate change’s threat to the fossil fuel business model. Following the pattern set by tobacco, pesticide, asbestos and tetraethyl lead producers, Exxon circled the tankers and fought against progress on climate. ...
. . . When the American conservative media machine kicks into action, it is an awesome thing, taking no prisoners while apparently serving as a real job-killer for the fact-checking community. I (Peter Dykstra) found dozens of opinion pieces, editorials, and unbalanced news stories in the three-week period from March 31 to April 22, all embracing ExxonMobil’s trampled free speech rights in the face of investigative reports and meddlesome Attorneys General.
Curiously, not a single one of these First Amendment themed tomes made mention of the years of harassment, threats, bottomless FOIA requests, and Congressional inquiries targeting actual climate scientists.
From “mainstream” sources like Bloomberg and USA Today to movement mouthpieces like the Washington Times and National Review to countless ideological blogs and websites, the message repeated as if it were spit out of a photocopier. The Washington Post ran not one but two Exxon-victim pieces on April 22 (Happy Earth Day, y’all!)
As promised earlier here is a reposting of a recent article written by Sou over at HotWhopper.com. In it she takes a closer look Dave Burton's statements and then clearly explains how he's manipulated facts to fabricate his lying talking points.
Over at WUWT, deniers are clutching at straws to continue to reject science in the face of all the "hottest evers". They really, really liked the last big El Nino in 1997-98, but they really, really dislike this current El Nino of 2015-16. It means they'll have to wait a while before they can start pointing to a drop in the surface temperature although Anthony Watts keeps jumping the gun and is excitedly telling his readers that a La Nina is just about here.
Here is some of what they got up to today, with a moan and lots of misdirection from a WUWT regular commenter called Dave Burton about another bane of deniers' existence - rising seas (archived here). But first, what's been happening...
This visualization shows total sea level change between 1992 and 2014, based on data collected from the TOPEX/Poseidon, Jason-1, and Jason-2 satellites. Blue regions are where sea level has gone down, and orange/red regions are where sea level has gone up. Since 1992, seas around the world have risen an average of nearly 3 inches.
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It's not a trick - sea level rise is accelerating
Dave Burton is complaining about a NASA web page on sea level. The chart at the top on the right hand side is from satellite readings. Remember, deniers love satellites in areas where the readings are difficult and have wide error margins, like lower tropospheric temperature. They don't like satellite readings when the error margins are smaller and the results don't suit their purpose, like sea level change. Here is the chart Dave didn't like:
NASA also showed a chart of sea level derived from tide gauge analysis from John Church and Neil White of the CSIRO, and didn't put up a big sign saying what the trend was. What Dave Burton didn't point out and maybe didn't even see, was that the chart only showed data to 2000. (I don't know why there isn't a plot using the most recent data.) Anyway, Dave probably missed seeing that because he didn't read the label in big letters, and didn't look at the x axis which was from 1870 to 2000:
So there's an entire article at WUWT all complaining that there wasn't a little sign up the top of the tide gauge data (to 2000) when there was a little sign about the satellite record (to 2016). Dave Burton's whiny WUWT article starts off with this piece of conspiracy theorising:
NASA’s tricky sea level newsletter
Anthony Watts / 6 hours ago April 7, 2016
Dave Burton writes:
Those NASA guys are tricky.
Click the “Update: Sea level change / Ocean rising at 3.42 mm per year” link in their latest Newsletter and you’ll see the big, bold “3.42 mm/yr” near the top of the web page, and two very similar-looking graphs of sea-level: one from satellites, and one from tide stations.
Since only one rate of sea-level rise is shown, the casual observer is likely to think that the same 3.42 mm/yr rate applies to both graphs. Here’s a screenshot:
Under the chart, Dave Burton says to "Look closer at the scales, and do the arithmetic". Pity he didn't take his own advice. The rate of change of the top chart is the rate of change for the period from 1993 to 2016. The rate of change of the bottom chart, or what Dave said he estimated, was for the period from "the late 1920s" to 2000. Those are different periods. Dave wrote:
Since the late 1920s it shows a slope of about 1.8 mm/yr, with no evidence of acceleration. But those tricky NASA guys scaled it to look like the slope is about the same as the first graph. It’s pretty obvious why they didn’t show a rate of sea-level rise for that graph.
Dave Burton's tricks
Dave Burton ranks highly on the conspiracy theory meter thinking NASA is out to trick deniers who don't know how to read a chart. What about the data? What tricks is Dave Burton trying to pull? :D
From the late 1920s to 2000 or so, the slope is 1.8 mm/year. From 1993 to 2016 the rise has been 3.42 mm/year. That means Dave is wrong. There is evidence of acceleration.
While deniers like to claim that the rate of sea level rise hasn't increased, if you go by what Dave Burton is saying, he's accepting there has been an acceleration of sea level rise. It used to be less than 2 mm a year and now it's up to 3.42 mm a year.
The paper by Church and White (2006) used tide gauge data through to 2001, with the data downloadable from the CSIRO website. In that paper the authors look at the data in different ways. For example, because there is a slope change, they wrote that you could: "do linear regressions on the two halves (1870– 1935 and 1936 –2001) of the record. The slopes are 0.71 ± 0.40 and 1.84 ± 0.19 mm yr 1 respectively". That 1.84 mm / year is close enough to Dave's estimate though the periods are slightly different.
The other thing is that Dave complains about adjustments to the tide gauge data. He wrote:
What’s more, the second graph is not really just from tide gauge data; it’s from tide gauge data inflated by a +0.3 mm/yr GIA “adjustment,” to subtract off the rate by which the sinking ocean floor is hypothesized to reduce sea-level rise.
He reckons that this is wrong and that "The real rate of coastal sea-level rise from averaged tide gauge measurements is only about 1.4-1.5 mm/yr (under six inches per century), and that rate hasn’t increased since the late 1920s." He quoted from the website of some denier who referred to a NOAA tide gauge website, which reported "the absolute global sea level rise is believed to be 1.7-1.8 millimeters/year". That looks to be in need of an update. But more importantly, Dave saw fit to subtract the GIA adjustment from the NOAA data when it wasn't applied in the first place. He's a double adjuster.
There's sea level rise and there's sea level rise
There are at least two main reasons for people wanting to know about sea level rise:
Coastal planning and management
Monitoring global climate change
The thing is that for coastal planning, what people want to know is how much and how fast the sea will encroach on the coastline. They need to know the sea level relative to the local land. That will vary depending on where you are. The NASA website Dave was moaning about is for global climate change. (In case you missed it there's a big clue on the top left of the web page.) In that case the information needed is how fast are the oceans filling up? How quickly is ice melting. How quickly is the warmer water expanding? That's a different purpose and scientists need to have an indication of the change in the total volume of water in the world's oceans. That's why they allow for glacial isostatic adjustment.
Dave doesn't want to adjust the global tide or other sea level data to allow for glacial isostatic changes? What about barometric adjustments - does he approve of that? What about slippage where the tide gauge sinks or rises relative to the land surface? Does he want that adjusted for? Why doesn't he just pull a number out of the air and claim that the seas are falling? I think that probably what is happening, apart from Dave wanting to reject any and all climate science, is that he is mixing up the data and the purpose for which the data are used.
If he's concerned about the coast where he lives, then he'll need local information more than global. Different coastlines have markedly different rates of rising and sinking relative to the sea level. There's been a lot of research into what happens around the world.
On the other hand, John Church and Neil White were researching global change in their more recent 2011 paper (as in previous papers). In the introduction they explain:
Correctly estimating historical sea-level rise and representing global ocean heat uptake in climate models are both critical to projecting future climate change and its consequences. The largest uncertainty in projections of sea-level rise up to 2100 is the uncertainty in global mean sea level (GMSL) and thus improving estimates of GMSL rise (as well as regional variations in sea level) remains a high priority.
The fact that they were looking at global change, not local change, is why they allowed for glacial isostatic adjustment, and wrote:
Here, the ongoing response of the Earth to changes in surface loading following the last glacial maximum were removed from the tide-gauge records using the same estimate of glacial isostatic adjustment (GIA; Davis and Mitrovica 1996; Milne et al. 2001) as in our earlier study (Church et al. 2004).
John Church and Neil White know what they are doing. They tested for all sorts of things and added that they even tested for the impact of the changes in dam storage, writing:
We tested the impact of correcting the tide-gauge measurements for terrestrial loading and gravitational changes resulting from dam storage (Fiedler and Conrad 2010). For the large number of tide gauges used in the period of major dam building after 1950 (mostly over 200), the impact on global mean sea level is only about 0.05 mm year−1 (smaller than the 0.2 mm year−1 quoted by Fiedler and Conrad, which is for a different less globally-distributed set of gauges). Tests of similar corrections for changes in the mass stored in glaciers and ice caps, and the Greenland and Antarctic Ice Sheets show that these effects have an even smaller impact on GMSL.
Glacial isostatic adjustment
If you're wondering about glacial isostatic adjustments, there's some information on the U Colorado sea level page. What it is is the mantle is still responding to the reduction in ice cover from around 20,000 years ago. Ice is heavy. When it melts, it means that some land surfaces pop up higher and the bottom of some oceans are falling relative to the Earth's centre. In other words, the oceans are getting bigger. If it wasn't for global warming, the sea level would be falling if there were no change in the actual volume of sea water. The CU Sea Level Research Group said in 2011 that "Including the GIA correction has the effect of increasing previous estimates of the global mean sea level rate by 0.3 mm/yr."
Meg Rosenburg submitted a video to the 2013 AGU student contest on the subject of glacial isostatic adjustment, which will give you some idea of the cause and effects:
AGU Student Video Contest: Rebound: An Earth Story
Description: My submission is an education video about glacial isostatic adjustment, why we have glacial and interglacial periods, how we can reconstruct climate history, and how the Earth is responding to the retreat of the continental glaciers. I found that this topic brings together a lot of different areas of study relevant to AGU, from geophysics, to orbital mechanics, to geochemistry.
If you have the time, there are 17 videos from the Permanent Service for Mean Sea Level 80th Anniversary Workshop on Sea-Level Science, including one specifically on glacial isostatic adjustment, by Giorgio Spada.
How much has the volume of ocean water changed?
You can see the chart in Figure 1 up top to see how much the volume of water in the ocean has changed in recent years. On the CSIRO website there's a data update of Church and White (2011), which goes up to 2013 for tide gauges and 2014 for satellite (altimeter), and is plotted below. The data are available at different levels of detail. I've just plotted the annual data. The faint grey lines are the upper and lower error margins for the tide gauge data. I've added linear trend lines for different periods as shown in the legend and on the chart. (Hover over the chart to see more detail):
It's obvious from the above that the rate of sea level rise has been increasing. However the CSIRO website has a caution and a reference to a workshop. I'm not sure what it means, but I'll copy it below:
We are currently attempting to more thoroughly evaluate the methodology and to improve the reconstruction so that it better represents the variability (Legresy et al., Workshop on Global and Regional Sea Level variability and change, Mallorca, Spain, June 2015).
Dr John Church’s record in sea-level rise research, with CSIRO colleagues, the Antarctic Climate & Ecosystems Cooperative Research Centre, and international climate science agencies, has helped generate a new benchmark in understanding the science and issues of sea-level rise.
Dr Church is coordinating lead author of the Sea Level Change chapter of the IPCC Fifth Assessment Report. As the Secretary-General of the World Meteorological Organisation, Michel Jarraud, highlights in his foreword: 'The findings in this book will help set priorities for research and for observational activities over the next decade that will contribute to future assessments of the IPCC. In turn, improvements in these assessments will better inform governments, industry and society in their efforts to formulate sound mitigation an adaptation responses to rising greenhouse gas concentrations and sea level, and their economic and social consequences.'
More about sea level changes
As well as the videos I talked about earlier, there's the 2011 video with Jerry X. Mitrovica of Harvard, in which he addresses some of the false claims by fake sceptics. (He also says what many of us have found, that by investigating denier's claims, you can learn much.) I recommend these two Mitrovica talks, fascinating and eye opening.
Postmodern Geophysics and Ice Age Climate
Published on May 14, 2014
Lecture given at Oregon State University on May 9, 2014 by Jerry X. Mitrovica
What do ancient eclipse records kept by Babylonian, Chinese, Arabic and Greek
scholars, and fish tanks, built by wealthy Romans during100BC-100AD, contribute to our understanding of modern climate change? Dr. Jerry X. Mitrovica will describe the important role these archaeological treasures have played in the understanding of sea-level rise and how they help scientists both "fingerprint" sources of recent sea level changes and make more accurate projections of future sea levels.
Jerry X. Mitrovica, Ph.D., is a Professor of Geophysics in the Department of Earth and Planetary Sciences at Harvard University, a Fellow of the American Geophysical Union, and the Director of the Earth Systems Evolution Program of the Canadian Institute for Advanced Research.
It's only by luck of being rained out that I've had a couple days to work on investigating and responding to Dave Burton's challenge. In the process I've found that he's gotten around and that others have put effort into pointing out Dave's many calculated deceptions. Since I don't know when I'll be able to finish working on Dave's comments, I figure I might share this from June of 2012. It demonstrates quite clearly what kind of disingenuous character we are dealing with here. (hopefully tomorrow I'll have time to repost http://blog.hotwhopper.com/2016/04/dave-burton-wants-to-level-seas-at-wuwt.html another eye opener.)
Dave Burton of NC 20 published a reply here to recent post I did about natural and human-caused sea level rise, “Sea Level Rise 101“. This is a reply to his post and a clarification of some of his many misconceptions about sea level rise science.
I want to start by saying that my interests in the NC sea level rise issue are not at all political. I am neutral on what coastal communities should do as adaptation measures to sea level rise and other impacts of climate change. I also have mixed opinions about what role the state and federal government should play in such social adaptation (i.e., I am not condoning any changes in coastal regulatory policy). My only interest in this issue is science and truth. The people of North Carolina – indeed the members of NC 20 – should know about the real science of sea level rise. Not the junk science being created and promoted by climate change deniers like Dave Burton and John Droz, Jr.
Now, on to Dave’s response. First up, this graphic:
Looking at ncdave's next comments over at CC, he confides,"Disclosure: I was an Expert Reviewer on the IPCC's AR5 Report."and we come to find out we're dealing with Dave Burton creator of the faux-science "sealevel.info" blog. The guy believes Heartlandis the scientific gold standard. Come on, look at their mission statement, it has nothing to do with understanding our planet. Policy advocacy is all they are concerned with. That's not science, that's power-politics PR games.
Dave's big on conspiracy ideation against established science and he believes Heartland's incestuous little NIPCC is more reliable than the thousands of reports and studies that have gone into the IPCC reports. And he's got the list to prove it, that's why I've included AGW Observer's 'Anti-AGW papers debunked' list after our excursion into Mr. Burton's expert comment.
You may ask what qualifies Dave to be an IPCC "Expert Reviewer"? Turns out, he doesn't need any qualification, just enough interest to sign up with the IPCC. As Tim Lambert explained “Expert reviewer for the IPCC” doesn't mean that they asked him to review material – all it means is that he asked to see the draft report. The only real requirement to be a reviewer is to sign an agreement not to publicly comment on the draft.” (see http://scienceblogs.com/deltoid/2006/05/09/you-too-can-be-a-leading-clima/) - or to be formal:
1. First Order Draft: Expert Review
… Experts who have not received an invitation but would like to review the draft are able to advise the Working Group Technical Support Units of this. Expert reviewers are issued with a username and password to access the first order drafts online.- See more at: https://www.nzclimatechangecentre.org/ipcc/expert_review#sthash.lMdGC94d.dpuf
I have a three year old post over at my CC site, "Jerry Mitrovica: The Fingerprints of Sea Level Change... the video" and in the past few days it's received a half dozen comments from one ncdave4life, who disputes Dr. Mitrovica's conclusions with echo-chamber science. Ncdave's comments are tricky-dick affairs loaded with coding that blossoms when approved and posted. Since I'm not into those sorts of devious games, and WUWTW is not a billboard for contrarian lies I've kept the rest of his onslaught in moderation until I have the time to review them. Since today is an unexpected day off I'm going to look at his first comment. To me his work seems another excellent example of devious rhetoric intent on dumbing down readers, that goes beyond the realm of healthy constructive dialogue and "free speech' and into the realm of malicious mischief that ought to be legally actionable. I believe this ncdave4life has provided me with excellent examples of "criminal negligent" in action, as argued by Professor Lawrence Torcello' and written about at"Is misinformation about climate science criminally negligent?" - I want to be clear - though I often bring up Professor Torcello's work, this is my independent reading and my arguing his case is totally unaffiliated with the professor's own work. Among ncdave's dishonest tricks in this first comment, are dismissing AGW's hand in damaging and threatening global agricultural productivity with a chart of six US states and their agricultural productivity that ends at 2004. As if the past dozen years can be ignored, or that six US states are a proxy for the global situation. Furthermore, he fantasizes a struggle going on between plants and animals for available oxygen and CO2 and that society increasing atmospheric CO2 level is a good thing. Conveniently ignoring the heat issue; and the resultant biosphere disruption; and ocean acidification damaging and disrupting our ocean's food web. That's the short version, now on to DB's own words: __________________________________________________
ncdave4life said…
Your complaint that I “don’t allow for comments” on my critique is misplaced. I first posted my comments on YouTube, on Prof. Mitrovica’s video. The reason you can’t see them there, and respond to them, is that the NAS won’t let you. If the NAS hadn’t “ghosted” my comments on Prof. Mitrovica’s video, you could have responded there. But they don’t allow critical comments there, so I posted my comments on my own web site.
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… which does not allow critical comments either. Why do I already sense you are an adept at the art rationalizing?
ncdave: My sealevel.info web site is not a blog. It doesn’t run Wordpress or any other CM or blogging software, so there’s no provision for reader comments. But if you (or anyone else) find any errors, please let me know, and I will correct them. (highlight added)
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I'm finding all sorts of mistakes, we'll see if DB's word is worth anything.
I'm ever amazed at how little has changed so far as human thinking and the public discourse is concerned.Most of us continue to have no conception of, nor interest in, this thing we live on, planet Earth, nor for the biosphere we depend on for everything, nor for how all that is intimately tied to the state of our climate system.
The Republican/libertarian crowd has staked their existence on digging ever deeper into their Faith-Based reason-hating alternate reality. A place where the state of our planet's health shrinks to irrelevance, while their self-pity and self-interest inflates to consume their entire world outlook. As for those who see our Earth differently, who appreciate it's interwoven folds within folds of complexity and dynamic balance, well we're seen as their enemies. It all seems stupid and counterproductive, hopeless even. I can't understand why so few are speaking out and complaining about that general acceptance of lies, slander and irrelevant emotion charged distractions in a discussion of such profound consequences.
Lately work commitments have really piled up so my engagement with the AGW dialogue is pretty much shrunk down to quickie responds to those depressingly childish YouTube comments and my CFI 'hangout' - it bothers me that I can't focus on writing more, but hey, it's nice to still be in demand, and the jobs have been interesting, so I'm not complaining,… not too much. That's why I want to compensate by sharing some deep thoughts on the topic from someone who Presidents took advice from.
You see a couple days ago I came upon one of Stephen Schneider's last talks. Sad to think he's been gone nearly six years already. It was also sad to see how few people had viewed the video, because here's another example of what a scientist sounds like, and this scientist was among the most knowledgeable of the old timers. He was also unfettered by professional constraints, since he knew this was among his last opportunities to share and he's as worth listening to today as he was back then. Even more so, considering how little among human thinking and attitude has actually changed these years and how important some of his insights are.
Stephen Schneider interview (1/2): Crisis of Life. Biodiversity Climate Change Tipping Points
One of Stephen Schneider's last interviews. He was one of the world's leading climatologists and an outspoken advocate of global treaties to reduce greenhouse gases.
Sadly, he died on 19 July 2010, exactly one month after this interview was recorded on 19 June in Taipei, Taiwan. We interviewed Stephen Schneider as part of our Crisis of Life interview series in which we get relevant scientists to talk about the biodiversity crisis in plain terms.
In part ONE of the interview, Stephen Schneider answered the following questions:
- Would you describe how you imagine the world will change within the next few decades? (0:40)
- We know that systems, such as the climate system, can be pushed for a while, and it seems like not much is happening. But once a threshold is crossed, the system tips to another state. Could you elaborate on this? (4:00)
- One of the potential tipping points could be the effect of ocean acidification on ocean ecosystems, for example, coral reefs. Would you elaborate on this secondary effect of atmospheric greenhouse gases? (6:20)
- Because the risks of global change are so large, is it not immoral to base our decisions on purely economic cost-benefit analyses? (10:40)
In part TWO of the interview, Stephen Schneider answered the following questions:
- Should we focus more on quality of life than on continuous economic growth, which on this limited planet starts to look more and more like cancerous growth? (0:40)
- Climate and biodiversity researchers have suggested that protecting rainforests is a win-win-win strategy. Could you elaborate on this? (3:40)
- How can people be convinced that we need some global rules, some global agreements, without being accused of wanting to establish an all-powerful world government? (7:00)
- Talking about global governance, what would be your priorities, especially concerning biodiversity? (10:25)
Dr. Schneider is the Inaugural Visitor in the Zurich Financial Services Distinguished Visitors Program on Climate Change. He is the Melvin and Joan Lane Professor for Interdisciplinary Environmental Studies, Professor of Biological Sciences, and a Senior Fellow in the Woods Institute for the Environment at Stanford University. From 1973-1996 he served as a scientist at the National Center for Atmospheric Research, where he co-founded the Climate Project. His research focuses on climate-change science, integrated assessment of ecological and economic impacts of human-induced climate change, and identifying viable climate policies and technological solutions. He has consulted for federal agencies and White House staff in six administrations.
In any event, this comments thread keeps getting dragged back to CO2Science.org as though it were some gold standard, rather than the personal gold mine of the Idso clan, selling a deceptive and harmful fiction to a gullible public.
All the while these commenters ignore the many huge differences between the internal variability driven "Medieval Warm Period" and today's atmosphere with it's vastly enriched (thanks to us) insulation medium which is holding more heat within our planet's global climate system, yes that would include the oceans. They also insist that there's been no warming in the past 18 years, go figure.
While researching my response to a comment I came upon "More for the annals of climate misinformation" where Alicia Newton does a good job of describing the dishonest manipulation of data that website is guilty of. It makes me wonder why this sort of deliberate deception with far reaching political and societal consequences is so casually accepted.
I've taken the liberty of reposting the text as a public service and hopefully an invitation to consider saying enough of the crafty lies, time to come to terms with the real world. I follow Newton's article with long tracts of another educational write up by Höskuldur Búi Jónsson who continues this exploration into the ways in which CO2Science.org artfully reweaves and repackages serious scientific information in a way that totally distorts the actual truth within that information. This I follow with various bits of biographical information regarding CO2Science.org.
I’m all for a website that distills climate science papers into something easily understood by the general public, especially if it avoids the hype and hysteria all too often employed by headline news.
Such is the claim of CO2 Science, a weekly newsletter published by the not for profit Center for the Study of Carbon Dioxide and Global Change, with issues that include editorials, book and media reviews, and mini-reviews of the recent peer-reviewed literature.
But rather than its promise of “separating reality from rhetoric in the emotionally-charged debate that swirls around the subject of carbon dioxide and global change”, on the contrary CO2 Science twists the most recent science, ever so subtly, to suggest that there is no link between carbon dioxide levels and climate change.
For a case in point, check out the feature entitled “Medieval Warm Period Record of the Week”. This showcases records of temperature or environmental changes during the Medieval Warm Period (aka the Medieval Climate Anomaly). The conclusion is that if the MWP was warmer than present – still debated – obviously CO2 isn’t driving current warming. There is even a list of 576 scientists who have found evidence for the MWP – the thinly veiled conclusion being that they agree that an increase in CO2 isn’t behind the recent climate change.
