|Jennifer Marohasy portrait, 2008|
Jennifer Marohasy (born 1963) is an Australian biologist, columnist and blogger. She was a senior fellow at the free-market think tank the Institute of Public Affairs between 2004 and 2009 and director of the Australian Environment Foundation until 2008. She holds a PhD in biology from the University of Queensland. She is sceptical of anthropogenic global warming and co-authored a peer-reviewed paper in GeoResJ suggesting that most of the recent warming is attributable to natural variations. The research was welcomed by conservative media outlets and heavily criticised by climate scientists as methodologically flawed "junk science" that was unworthy of publication.
In 1997 she switched from researcher to environment manager with the Queensland sugar industry. In 2001, she started to develop an interest in environmental campaigns and, in particular, claiming that there are anomalies between fact and perception regarding the health of coastal river systems and the Great Barrier Reef.
In July 2003, she became director of the environment unit at the Institute of Public Affairs.
Her work at the Institute of Public Affairs
While head of the Environment Unit at the Institute of Public Affairs, Dr Marohasy compiled a backgrounder titled Myth and the Murray - measuring the real state of the river environment which was published by the Institute in December 2003. The Institute received a $40,000 donation from Murray Irrigation Limited at that time. This paper is quoted in the Interim Report of the Inquiry into future water supplies for Australia’s rural industries and communities of the House of Representatives Standing Committee on Agriculture, Fisheries and Forestry, March 2004. At a science round table of the committee, when asked for her views on how much water should be returned to the River Murray, Dr Marohasy argued that there was no need for additional flows at that time and that we should test the results of current environmental measures before committing to more.
Dr Marohasy was instrumental in establishing a joint programme with the Institute of Public Affairs and the University of Queensland, funded by Western Australian philanthropist, Dr Bryant Macfie (A top 20 Shareholder in Strike Resources Limited  ). Dr Marohasy is nolonger involved in the programme following objections to her involvement from the Australian Federation of Scientists and Technologists (FASTS).
Public position on global warming
In an Australian Broadcasting Corporation interview she stated that... "[i]t's not clear that climate change is being driven by carbon dioxide levels...whether or not we can reduce carbon dioxide levels, there will be climate change".
On the Australian Broadcasting Corporation Radio National program, Ockham's Razor, Dr Marohasy said in 2005... "I agree with Professor Flannery that we need to reduce atmospheric carbon dioxide levels".
In an interview on the Australian Broadcasting Corporation Radio National program, Counterpoint, she claimed recent cooling by starting with the extreme temperature peak of the 1998 El Niño event. She said that... "there has been cooling if you take 1998 as your point of reference. If you take 2002 as your point of reference then temperatures have plateaued. This is certainly not what you'd expect if carbon is driving temperature because carbon dioxide levels have been increasing but temperatures have actually been coming down over the last ten years. ...very unexpected not something that is being discussed. It should though be being discussed because it is very significant".
2017 GeoResJ manuscript
A paper that Marohasy co-authored with her Institute of Public Affairs colleague John Abbot, titled "The application of machine learning for evaluating anthropogenic versus natural climate change," was made available online on August 5, 2017. It was published in GeoResJ, a quarterly peer-reviewed journal in Earth Sciences that began publishing in 2014 and is to be discontinued from January 2018. Marohasy wrote about her findings in The Spectator Australia and in her blog, declaring that most of the warming that has occurred could be natural. "[E]ven if there had been no industrial revolution and burning of fossil fuels, there would have still been warming through the twentieth century — to at least 1980, and of almost 1 °C," she wrote. The paper also questions the equilibrium climate sensitivity, which relates to the extent of warming associated with a doubling of atmospheric levels of carbon dioxide. Abbot and Marohasy estimate a 0.6 °C temperature rise would result, well below the range of 1.5 to 4.0 °C estimated in reports from the Intergovernmental Panel on Climate Change (IPCC).
According to The Guardian, the paper was met with "delight in conservative media outlets, together with a distinct lack of any genuine scepticism." The Daily Caller state that the Abbot and Marohasy results "challenge the mainline conclusion" of the IPCC, and that their results show that the "world was about as warm in 1980 as it was during the Middle Ages,"  consistent with other claims about the Medieval Warm Period. Such claims relate to the so-called hockey stick graph and whether medieval warming was a global phenomenon, and have been extenisively examined by the IPCC. The scientific consensus is that warming in recent times is of greater significance than occurred in the medieval period. Breitbart went further, declaring that global warming is "almost certainly natural," that "it's the alarmists who have some apologizing to do" (in relation to the hockey stick controversy), and published a graph described (Figure 4 in the GeoResJ paper) as showing that "recent warming is well within the planet's natural historic climate boundaries" and which shows cooling in the period 1980-2000. Such cooling is inconsistent with the actual temperature record and the inconsistency is called the "divergence problem," according to Marohasy and the Daily Caller. Like Breitbart, the Daily Express presented the research as having major significance, declaring it "a shock new report which throws a spanner in the works of those who say global warming is a result of man-made activity."
Coverage by the Guardian's Graham Readfearn noted that none of the conservative media reports had sought views of the research amongst members of the scientific community. When Readfearn did so, he received severe criticisms of the work and its methods, and declarations that it was "junk science" (by David Karoly) and that the publication should be withdrawn. Methodological issues with the research and criticisms made included:
- Unexplained and selective use of proxy temperature records – only six were used and no reason was given for their choice, when a recent paper showed that there are at least 692 available. Their approach was criticised as "extremely unscientific" by Benjamin Henley of the University of Melbourne for making no attempt to compare their approach with actual temperature data. With results that are interpreted incorrectly and which do not support the conclusions, Henley stated that the paper should never have been published and should be withdrawn by the journal. Henley made harsher comments directly to Marohasy on twitter, describing the paper as "an absolute pile of rubbish" that "reads like a D-grade high school lab report and is utterly flawed."
- Gavin Schmidt, the Director of NASA's Goddard Institute for Space Studies, described that paper as an example of "what happens when people have their conclusions fixed before they start the work" and assessed it as "worthless." He identified an internal contradiction in their method, whereby equilibrium climate sensitivity was assumed to be solely due to natural internal variations (and thus excluding external factors including volcanic action and solar variations) despite this contradicting claims elsewhere in the paper. Schmidt also found that "something went wrong" in the digitisation of the results resulting in a temporal offset. Consequently, in the Northern Hemisphere data, "what they think is 2000, is actually 1965" and so at least 35 years of recent warming has been omitted. Schmidt put his criticisms direct to Marohasy on twitter, seeking her comments on his statement that her "conclusions are based on inaccurately cited data that's incorrectly scaled and incorrectly aligned in time." Marohasy rejected Schmidt's claims as "false" and declared that Schmidt was wrong when he suggested that they had used a smoothed version of the Moberg at al. (2005) data set.
- Piers Forster, the Director of the Priestley International Centre for Climate, criticised the "unphysical" approach taken in using extrapolation where measured data are available. For example, patterns of volcanic activity prior to 1880 have been extrapolated forward despite the actual pattern of volcanism in the previous 150 years being both well-known and significantly different from the period pre 1880.
- Author John Abbot was also criticised for claiming an affiliation to James Cook University, despite the manuscript being submitted well after his adjunct position ended.
Dr Vasile Ersek, of the UK's Northumbria University, was the journal editor who handled the manuscript, stated that "two independent referees" had reviewed it and that "neither found major flaws with the manuscript." Ersek also said he was "sorry to see it involved in a controversy."
Figure 4 of the Abbot and Marohasy publication, that has been used by Breitbart, was also reproduced by Marohasy in discussing her work on the Institute of Public Affairs website, and it has been attracting criticism. Zeke Hausfather of Berkeley Earth posted a copy to which he had added the actual temperature record since 2000, showing further warming of more than 1 °C, leading climatologist Michael Mann to comment that Marohasy has been caught "#HidingTheIncline." Hausfather further tweeted once he identified the source data as Moberg et al. (2005), noting a more appropriate comparison was to a land/ocean temperature record. Gavin Schmidt replied, noting that the data from Abbot and Marohasy for the twentieth century actually ends three decades too early, and asking Marohasy how fitting to a data set ending in 1972 can be useful in understanding current warming. He provided a graph corrected for this time offset and including actual temperature data to the current date. Marohasy described grafting instrumental temperature data onto a proxy data set of temperatures as "inappropriate," though Moberg grafted data together in a similar way (in Figure 2 of their paper).
Criticisms of BOM
Dr Marohasy claimed in the Australian media  that Cyclone Marcia's warning should be for a category 3 cyclone. The Bureau of Meteorology's Cyclone Marcia warning was for a category 5 cyclone. Dr Marohasy cited data from Middle Percy Island station showing maximum wind gusts of 208 kilometres per hour. BOM stated however, that the strongest winds of the cyclone were on the eastern side, some 40 kilometres per hour faster - typical for cyclones in the southern hemisphere. The cyclone was gaining in strength. Middle Percy Island was on the western side of the cyclone. Middle Percy Island measuring equipment was destroyed by the cyclone and therefore the BOM data stream ceased. Dr Marohasy's claim, that BOM's category 5 warning was based solely on computer modeling, was rejected by Bureau chief Rob Webb.
Professor Jonathan Nott, a James Cook University specialist in extreme natural events, said the bureau numbers showed it was a category 5 rather than a 3. "I would agree with the bureau", Professor Nott said. "Percy didn’t get the strongest winds. They were substantially stronger to the east".
- Melissa Fyfe, "Cool reception for new green group", The Age, 8 June 2005.
- Abbot, John; Marohasy, Jennifer (2017). "The application of machine learning for evaluating anthropogenic versus natural climate change". GeoResJ. 14: 36–46. doi:10.1016/j.grj.2017.08.001.
- Bastasch, Michael (August 22, 2017). "Advanced Computer Models Suggest Most Global Warming Is From Natural Forces". Daily Caller. Archived from the original on August 24, 2017. Retrieved August 26, 2017.
- Delingpole, James (August 22, 2017). "Delingpole: Global Warming Is Almost Entirely Natural, Study Confirms". Archived from the original on August 25, 2017. Retrieved August 26, 2017.
- Martin, Sean (August 22, 2017). "Climate Change - the REAL inconvenient truth: Scientist claims global warming is NATURAL". Daily Express. Retrieved August 26, 2017.
- Readfearn, Graham (August 26, 2017). "Why the IPA's claim global warming is natural is junk science". The Guardian Australia. Archived from the original on August 26, 2017. Retrieved August 26, 2017.
- Walton, Craig (2005). Reclaiming Lost Provinces: A Century of Weed Biological Control in Queensland. Department of Natural Resources & Mines, Queensland. Reviewed here
- Early Scientific Publications :: Publications
- Jennifer Marohasy, IPA Backgrounder Vol 15/5, December 2003,Myth and the Murray - measuring the real state of the river environment
- ABC Local Radio, VIC Country Hour, 04/06/2004, Institute of Public Affairs accepts irrigation funds.
- House of Representatives Standing Committee on Agriculture, Fisheries and Forestry,2004, Inquiry into future water supplies for Australia’s rural industries and communities
- AAP MediaNet Press Releases, Media Release: Institute of Public Affairs, 30 April 2008; Andrew Trounson, Greg Roberts,"Climate sceptic's $350,000 grant to uni has `no strings attached'", The Australian, 7 May 2008
- The Australian, 7 May 2008. Dispute over climate sceptic uni grant
- Report released on climate change - Broadcast 7/26/05
- Ockham's Razor - Broadcast 11/20/05
- 1997-1998 El Nino: the most recent event, Department of Atmospheric Science, University of Illinois
- Interview on Counterpoint - Broadcast 3/17/2008
- Wesselius, Tobias (June 19, 2013). "Elsevier Launches Open Access Journal: GeoResJ" (Press release). Elsevier. Archived from the original on June 24, 2013. Retrieved August 26, 2017.
- Wesselius, Tobias; Lehane, Clare (June 19, 2013). "New GeoResJ is Elsevier's first open-access journal in earth science". Archived from the original on October 17, 2013. Retrieved August 26, 2017.
- King, Scott; Donovan, Steve; George, Simon; Jaeglé, Lyatt; Pyle, David; van Gasselt, Stephan; Ersek, Vasile (2014). "Beginnings". GeoResJ. 1–2: ii. doi:10.1016/j.grj.2013.11.001.
Available online 3 December 2013.
- "GeoResJ". Elsevier. 2017. Archived from the original on August 22, 2017. Retrieved August 26, 2017.
GeoResJ will be discontinued from January 2018 and is closed to new submissions. ... All published papers will remain available on ScienceDirect.
- Marohasy, Jennifer (August 21, 2017). "Big data finds the Medieval Warm Period – no denial here". The Spectator Australia. Archived from the original on August 23, 2017. Retrieved August 26, 2017.
- Marohasy, Jennifer (August 21, 2017). "Most of the Recent Warming Could be Natural". jennifermarohasy.com. Archived from the original on August 23, 2017. Retrieved August 26, 2017.
- Bastasch, Michael (December 13, 2013). "Study: Earth was warmer in Roman, Medieval times". Daily Caller. Archived from the original on December 17, 2013. Retrieved August 26, 2017.
- Crowley, Thomas J.; Lowery, Thomas S. (2000). "How Warm Was the Medieval Warm Period?". AMBIO. 29 (1): 51–54. doi:10.1579/0044-7447-29.1.51.
- Osborn, Timothy J.; Briffa, Keith R. (2006). "The Spatial Extent of 20th-Century Warmth in the Context of the Past 1200 Years". Science. 311 (5762): 841–844. doi:10.1126/science.1120514. PMID 16469924.
- "5.3.5 Temperature Variations During the Last 2000 Years". Chapter 5: Information from Paleoclimate Archives. IPCC Fifth Assessment Report. Intergovernmental Panel on Climate Change. 2013. pp. 409–415.
- PAGES2k Consortium (2017). "A global multiproxy database for temperature reconstructions of the Common Era". Sci. Data. 4: 170088. doi:10.1038/sdata.2017.88.
- Henley, Ben [@benhenley] (August 25, 2017). "The paper by Abbot and @JennMarohasy reads like a D-grade high school lab report and is utterly flawed. What an absolute pile of rubbish" (Tweet). Archived from the original on August 26, 2017. Retrieved August 26, 2017 – via Twitter.
- Schmidt, Gavin [@ClimateOfGavin] (August 23, 2017). "Hey @JennMarohasy, Your conclusions are based on inaccurately cited data that's incorrectly scaled & incorrectly aligned in time. Comments?" (Tweet). Archived from the original on August 26, 2017. Retrieved August 26, 2017 – via Twitter.
- Marohasy, Jennifer [@JennMarohasy] (August 23, 2017). "reject your false claims, and is inappropriate that u graft instrumental thermometer HadCRUT record onto proxy record" (Tweet). Archived from the original on August 26, 2017. Retrieved August 26, 2017 – via Twitter.
- Marohasy, Jennifer [@JennMarohasy] (August 23, 2017). "sorry, wrong data set, we use proxy record, not HadCRUT" (Tweet). Archived from the original on August 26, 2017. Retrieved August 26, 2017 – via Twitter.
- Schmidt, Gavin [@ClimateOfGavin] (August 23, 2017). "There's more to it! Their time axis is off by ~35 years and magnitude is too large by ~10%. So their '20th C' is actually 1845-1965" (Tweet). Archived from the original on August 26, 2017. Retrieved August 26, 2017 – via Twitter.
- Moberg, Anders; Sonechkin, Dmitry M.; Holmgren, Karin; Datsenko, Nina M.; Karlén, Wibjörn (2005). "Highly variable Northern Hemisphere temperatures reconstructed from low- and high-resolution proxy data". Nature. 433 (7026): 613–617. doi:10.1038/nature03265.
- Marohasy, Jennifer (August 24, 2017). "Most of the Recent Warming Could be Natural". Institute of Public Affairs. Archived from the original on August 26, 2017. Retrieved August 26, 2017.
- "Zeke Hausfather". Berkeley Earth. 2017. Retrieved August 26, 2017.
- Hausfather, Zeke [@hausfath] (August 22, 2017). "This new tree ring proxy reconstruction that Breitbart is claiming shows "global warming almost entirely natural" is missing something.." (Tweet). Archived from the original on August 26, 2017. Retrieved August 26, 2017 – via Twitter.
- Mann, Michael E. [@MichaelEMann] (August 22, 2017). "Oops. It seems that @BreitbartNews & the co-authors of this "study" were caught #HidingTheIncline" (Tweet). Archived from the original on August 27, 2017. Retrieved August 27, 2017 – via Twitter.
- Hausfather, Zeke [@hausfath] (August 22, 2017). "So a bit of detective work found that reconstruction featured in Breitbart was actually from Moberg et al 2005, and extends through 1979 1/2" (Tweet). Archived from the original on August 26, 2017. Retrieved August 26, 2017 – via Twitter.
- Hausfather, Zeke [@hausfath] (August 22, 2017). "Moberg '05 is a land/ocean N. Hem, so comparison to instrumental land/ocean temps is more appropriate (HT @thirstygecko @ClimateOfGavin) 2/2" (Tweet). Archived from the original on August 26, 2017. Retrieved August 26, 2017 – via Twitter.
- Schmidt, Gavin [@ClimateOfGavin] (August 23, 2017). "Please let us know how a fit to a record w/last point in 1972 tells us about the "present" warming (PS. last year was 2016)" (Tweet). Archived from the original on August 26, 2017. Retrieved August 26, 2017 – via Twitter.
- Rabett, Eli [@EthonRaptor] (August 23, 2017). "So why did Moberg do it? rabett.blogspot.com/2017/08/marohasy-mess-up.html .." (Tweet). Archived from the original on August 26, 2017. Retrieved August 26, 2017 – via Twitter.
- Courier Mail - You Call that a Category 5?
- Tropical Cyclone Marcia to reach Category 5 system at landfall
- Latest Weather Observations for Middle Percy Island
- Dr Marohasy, "Just before the cyclone made landfall it passed over Middle Percy Island ... A wind gust of 208 km/hr was recorded at 4.30 am, which suggests Marcia was almost a Category 3 at this time"
- Professor Jon Nott Profile - James Cook University