Craig Loehle

Craig Loehle
Residence Naperville, Illinois
Fields Forest ecology, Environmental science
Institutions National Council for Air and Stream Improvement
Alma mater University of Georgia, University of Washington, Colorado State University
Thesis SAGEGRASS : a sagebrush-grass grazingland ecosystem simulation model (1982)

Craig Loehle is an American ecologist, the chief scientist at the National Council for Air and Stream Improvement, based in Naperville, IL, and a global warming skeptic.

Scientific career

Loehle worked as a research ecologist at Savannah River Laboratory from 1987 to 1991, and in the environmental research division at Argonne National Laboratory from 1991 to 1998.[1] While at Argonne, he conducted research which found that trees can grow to maturity up to a thousand miles south of their natural ranges, but only fifty to a hundred miles north of their natural ranges.[2]

Scientific discovery and success

In 1990, in a paper in the journal BioScience, Loehle coined the term "Medawar zone" to refer to a scientific task which is only moderately difficult but still yields the maximum payoff. He named it after Peter Medawar, a Nobel Prize-winning scientist who once wrote that there seems to be a certain time when scientific questions seem especially ripe for answering, whereas other questions remain elusive and out-of-reach from investigation.[3] Loehle has also argued that academia is biased toward appointing mediocre scientists.[4]

Climate change research

In 2004, Loehle published a study which concluded that "global and northern hemisphere temperature will drop on century scale in the next 20 years."[5][6]

He appeared at the 2008 International Conference on Climate Change (ICCC), held by the Heartland Institute,[7] and made another appearance at this conference in 2012.[8]

In 2007, Loehle published a paleoclimate reconstruction which reconstructed temperatures over the last 2,000 years, in Energy & Environment. It made a point of not using tree-ring data, unlike the better-known "hockey stick graphs" by Michael E. Mann, and concluded that, contrary to the scientific consensus on the matter, recent global temperatures are not unprecedented over the past 1,000 years.[9][10][11][12] This paper was criticized by Gavin Schmidt, who wrote on the blog RealClimate that "the Loehle reconstruction has mistakenly shifted all three of these records forward by 50 years (due to erroneously assuming a 2000 start date for the ‘BP’ time scale)."[13] Loehle later acknowledged this error, and published a correction the following year. In the correction, he and J. Huston McCulloch (Ohio State University) concluded that there was "little change in the results" after the aforementioned errors were corrected for.[14] In Mann's book, "The Hockey Stick and the Climate Wars," he states that Schmidt was correct in saying that Loehle had dated his graph relative to 2000, whereas paleoclimatologists conventionally use 1950 as the BP, or "Before Present," base year. He also stated that Loehle's paper suffered from other flaws, such as the fact that some of the sediment records Loehle had used to construct his graph were based on only a few measurements spread out over a 2,000-year period, and that, as a result, the uncertainty range around these measurements is too large for them to be compared to present-day temperatures.[15]

A 2009 paper by Loehle reported that the global oceans had been cooling since 2003.[16][17]

A 2014 study by him concluded that climate sensitivity was 1.99 °C, with a 95% confidence limit of 1.75-2.23 °C.[18][19] A subsequent comment paper led by Dr Gavin Cawley of the University of East Anglia[20] stated that the Loehle calculations were based on a "flawed methodology" that "systematically underestimates the transient climate response, due to a number of unsupportable assumptions". Once these assumptions were relaxed, the Loehle estimated range of equilibrium climate sensitivity increased from 1.75-2.23 °C to 2.33-5.34 °C, a similar range to that covered by CMIP5 computer simulations. The Cawley paper also stated that the Loehle approach was "little more than a curve-fitting exercise" that is not based on physics. When an even simpler model is used which is based on physics, the calculated climate response is also larger than that calculated by Loehle.

Views on climate change

Loehle has argued that the divergence problem means that tree ring data is an unreliable indicator of past temperatures.[21] In 2012, Loehle said that while many animal species have gone extinct in recent years, that this was not caused by global warming but rather by humans hunting them and introducing pests and diseases.[22]

References

  1. ↑ Craig Loehle, Heartland Institute website
  2. ↑ Singer, S. Fred (2006). Unstoppable Global Warming: Every 1,500 Years. Rowman & Littlefield. p. 81.
  3. ↑ Eley, Adrian (2012). Becoming a Successful Early Career Researcher. Routledge. p. 16.
  4. ↑ Loehle, Craig (10 January 1998). "Forum : Superstars need not apply - Mediocrity rules too often when it comes to appointing academics, says Craig Loehle". New Scientist. Retrieved 21 March 2014.
  5. ↑ Loehle, Craig. "Climate change: detection and attribution of trends from long-term geologic data". Ecological Modelling 171 (4): 433–450. doi:10.1016/j.ecolmodel.2003.08.013.
  6. ↑ Carter, Bob (20 January 2009). "Facts debunk global warming alarmism". The Australian. Retrieved 11 May 2014.
  7. ↑ Morano, Marc (22 December 2008). "Prominent Scientist Fired By Gore Says Warming Alarm ‘Mistaken’". Senate Committee on Environment and Public Works. Retrieved 7 February 2014.
  8. ↑ Enhanced Crop, Forest, and Ecosystem Health in a Warmer World
  9. ↑ Loehle, Craig (2007). "A 2000 Year Global Temperature Reconstruction based on Non-Tree ring Proxies" (PDF). Energy & Environment 18 (7 & 8): 1049–1058.
  10. ↑ Milloy, Steven (21 November 2007). "U.N. Climate Distractions". Fox News Channel. Retrieved 13 February 2014. A new temperature reconstruction for the past 2,000 years created by Craig Loehle of the National Council for Air and Stream Improvement indicates that, 1,000 years ago, globally averaged temperature was about 0.3 degrees Celsius warmer than the current temperature.
  11. ↑ Singer, S. Fred (9 January 2010). "Index of Editorials Global Warming Junkscience". Science and Environmental Policy Project. Retrieved 1 February 2014.
  12. ↑ "Skeptics, unite!". National Post. Retrieved 1 February 2014.
  13. ↑ Past reconstructions: problems, pitfalls and progress
  14. ↑ Loehle, Craig; McCulloch, J. Houston (2008). "Correction to: A 2000 Year Global Temperature Reconstruction based on Non-Tree ring Proxy Data" (PDF). Energy & Environment 19 (1): 93–100.
  15. ↑ Mann, Michael E. (2012). The Hockey Stick and the Climate Wars. Columbia University Press. p. 188.
  16. ↑ Loehle, Craig (1 January 2009). "Cooling of the Global Ocean Since 2003". Energy & Environment 20 (1): 101–104. doi:10.1260/095830509787689141.
  17. ↑ van Kooten, G. Cornelis (2009). Climate Change, Climate Science and Economics: Prospects for an Alternative Energy Future. Springer Science+Business Media. p. 158.
  18. ↑ Loehle, Craig (March 2014). "A minimal model for estimating climate sensitivity". Ecological Modelling 276: 80–84. doi:10.1016/j.ecolmodel.2014.01.006.
  19. ↑ Michaels, Patrick (28 February 2014). "More Evidence for a Low Climate Sensitivity". Cato Institute. Retrieved 14 November 2014.
  20. ↑ Cawley, Gavin (November 2014). "On a minimal model for estimating climate sensitivity". Ecological Modelling 297: 20–25. doi:10.1016/j.ecolmodel.2014.10.018.
  21. ↑ Spencer, Roy (2012). The Great Global Warming Blunder. Encounter Books. pp. 10–11.
  22. ↑ Rothbard and Driessen (15 June 2012). "U.N.’s threat to biodiversity". Washington Times. Retrieved 22 March 2014.
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