Craig Loehle

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

Craig Loehle is an American ecologist. He is a principal scientist at the National Council for Air and Stream Improvement, a forest industry-funded research institution. He is also a policy expert for The Heartland Institute, a think tank famous for sponsoring climate change denial. [1] [2] [3] [4]

Contents

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. [5] 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. [6]

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. [7] [8]

Climate change research

Loehle produced a paleoclimate reconstruction of temperatures over the last 2,000 years which avoided tree ring records on the basis that these were flawed, and used 18 series from a variety of other climate proxies. It was published on 1 December 2007 in Energy & Environment , [9] a journal with a reputation for publishing papers promoting climate change denial. It became part of the hockey stick controversy as, unlike all other reconstructions, it showed Medieval Warm Period (MWP) temperatures warmer than current levels. [10] Climatologists promptly highlighted various problems which should have been identified in peer review, including the mistaken assumption that the climate proxies were in years before 2000 when the scientific convention is that Before Present is years before 1950. [10] [11] The paper had shown the "MWP being approximately 0.3°C warmer than 20th century values at these eighteen sites", [9] on 1 January 2008 Loehle published a correction jointly with J. Huston McCulloch (Ohio State University Economics Department) which concluded that there was "little change in the results", and the "warmest tridecade of the MWP was warmer than the most recent tridecade, but not significantly so." [12] The corrected reconstruction as featured in the IPCC Fifth Assessment Report was assessed as showing it likely that the warmest tridecade in the MWP was colder than the 1983–2012 mean instrumental temperature. [13]

A 2014 study by him concluded that climate sensitivity was 1.99 °C, with a 95% confidence limit of 1.75-2.23 °C. [14] [15]

Related Research Articles

Instrumental temperature record In situ measurements that provides the temperature of Earths climate system

The instrumental temperature record provides the temperature of Earth's climate system from the historical network of in situ measurements of surface air temperatures and ocean surface temperatures. Data are collected at thousands of meteorological stations, buoys and ships around the globe. The longest-running temperature record is the Central England temperature data series, which starts in 1659. The longest-running quasi-global record starts in 1850. In recent decades more extensive sampling of ocean temperatures at various depths have begun allowing estimates of ocean heat content but these do not form part of the global surface temperature datasets.

Temperature record of the past 1000 years Temperature trends since AD 1000

The temperature record of the past 1,000 years or longer is reconstructed using data from climate proxy records in conjunction with the modern instrumental temperature record which only covers the last 150 years at a global scale. Large-scale reconstructions covering part or all of the 1st millennium and 2nd millennium have shown that recent temperatures are exceptional: the Intergovernmental Panel on Climate Change Fourth Assessment Report of 2007 concluded that "Average Northern Hemisphere temperatures during the second half of the 20th century were very likely higher than during any other 50-year period in the last 500 years and likely the highest in at least the past 1,300 years." The curve shown in graphs of these reconstructions is widely known as the hockey stick graph because of the sharp increase in temperatures during the last century. As of 2010 this broad pattern was supported by more than two dozen reconstructions, using various statistical methods and combinations of proxy records, with variations in how flat the pre-20th-century "shaft" appears. Sparseness of proxy records results in considerable uncertainty for earlier periods.

Michael E. Mann American physicist and climatologist

Michael Evan Mann is an American climatologist and geophysicist, currently director of the Earth System Science Center at Pennsylvania State University, who has contributed to the scientific understanding of historic climate change based on the temperature record of the past thousand years. He has pioneered techniques to find patterns in past climate change, and to isolate climate signals from noisy data.

The Center for the Study of Carbon Dioxide and Global Change is a 501(c)(3) non-profit organization based in Tempe, Arizona. The Center produces a weekly online science newsletter called CO2Science.

Description of the Medieval Warm Period and Little Ice Age in IPCC reports

The description of the Medieval Warm Period and Little Ice Age in IPCC reports has changed since the first report in 1990 as scientific understanding of the temperature record of the past 1000 years has improved. The Medieval Warm Period (MWP) and Little Ice Age (LIA) are the best-known temperature fluctuations in the last millennium.

Climate sensitivity is the globally averaged temperature change in response to changes in radiative forcing, which can occur, for instance, due to increased levels of carbon dioxide (CO
2). Although the term climate sensitivity is usually used in the context of radiative forcing by CO2, it is thought of as a general property of the climate system: the change in surface air temperature following a unit change in radiative forcing, and the climate sensitivity parameter is therefore expressed in units of °C/(W/m2). The measure is approximately independent of the nature of the forcing (e.g. from greenhouse gases or solar variation). When climate sensitivity is expressed for a doubling of CO2, its units are degrees Celsius (°C).

Raymond S. "Ray" Bradley is a climatologist and University Distinguished Professor in the Department of Geosciences at the University of Massachusetts Amherst, where he is also research director of the Climate System Research Center. Bradley's work indicates that the warming of Earth's climate system in the twentieth century is inexplicable via natural mechanisms.

Global warming Current rise in Earths average temperature and its effects

Global warming is the long-term rise in the average temperature of the Earth's climate system. It is a major aspect of climate change, and has been demonstrated by direct temperature measurements and by measurements of various effects of the warming. The terms global warming and climate change are often used interchangeably. However, speaking more accurately, global warming denotes the mainly human-caused increase in global surface temperatures and its projected continuation, but climate change includes both global warming and its effects, such as changes in precipitation. While there have been prehistoric periods of global warming, many observed changes since the mid-20th century have been unprecedented over decades to millennia.

Hockey stick graph graph

Hockey stick graphs present the global or hemispherical mean temperature record of the past 500 to 2000 years as shown by quantitative climate reconstructions based on climate proxy records. These reconstructions have consistently shown a slow long term cooling trend changing into relatively rapid warming in the 20th century, with the instrumental temperature record by 2000 exceeding earlier temperatures.

Hockey stick controversy Controversy relating to the record of recent temperatures

In the hockey stick controversy, the data and methods used in reconstructions of the temperature record of the past 1000 years have been disputed. Reconstructions have consistently shown that the rise in the instrumental temperature record of the past 150 years is not matched in earlier centuries, and the name "hockey stick graph" was coined for figures showing a long-term decline followed by an abrupt rise in temperatures. These graphs were publicised to explain the scientific findings of climatology, and in addition to scientific debate over the reconstructions, they have been the topic of political dispute. The issue is part of the global warming controversy and has been one focus of political responses to reports by the Intergovernmental Panel on Climate Change (IPCC). Arguments over the reconstructions have been taken up by fossil fuel industry–funded lobbying groups attempting to cast doubt on climate science.

This is a list of climate change topics.

The Soon and Baliunas controversy involved the publication in 2003 of a review study written by aerospace engineer Willie Soon and astronomer Sallie Baliunas in the journal Climate Research, which was quickly taken up by the G.W. Bush administration as a basis for amending the first Environmental Protection Agency Report on the Environment.

Joseph D'Aleo is a certified consultant meteorologist and the first Director of Meteorology at The Weather Channel. He was chairman of the American Meteorological Society's Committee on Weather Analysis and Forecasting. He was the founder of the "Icecap" blog. He has been a contributing meteorologist to the Old Farmer's Almanac, in which he predicted in 2008 that the earth had entered a period of global cooling. D'Aleo is currently a meteorologist at Weatherbell Analytics.

The Wegman Report was prepared in 2006 by three statisticians led by Edward Wegman at the request of Rep. Joe Barton of the United States House Committee on Energy and Commerce to validate criticisms made by Stephen McIntyre and Ross McKitrick of reconstructions of the temperature record of the past 1000 years, in particular the reconstructions by Mann, Bradley and Hughes which had become the focus of the hockey stick controversy.

The North Report was a 2006 report evaluating reconstructions of the temperature record of the past two millennia, providing an overview of the state of the science and the implications for understanding of global warming. It was produced by a National Research Council committee, chaired by Gerald North, at the request of Representative Sherwood Boehlert as chairman of the U.S. House of Representatives Committee on Science.

The Nongovernmental International Panel on Climate Change (NIPCC) is a climate change denial advocacy organisation set up by S. Fred Singer's Science & Environmental Policy Project, and later supported by the Heartland Institute lobbying group, in opposition to the assessment reports of the Intergovernmental Panel on Climate Change (IPCC) on the issue of global warming.

Gabriele C. Hegerl British climatologist

Gabriele Clarissa Hegerl is German Professor of Climate System Science at the University of Edinburgh School of GeoSciences. Prior to 2007 she held research positions at Texas A&M University and at Duke University's Nicholas School of the Environment, during which time she was a co-ordinating lead author for the Intergovernmental Panel on Climate Change (IPCC) Fourth and Fifth Assessment Report.

Medieval Warm Period time of warm climate in the North Atlantic region lasting from c. 950 to c. 1250

The Medieval Warm Period (MWP) also known as the Medieval Climate Optimum, or Medieval Climatic Anomaly was a time of warm climate in the North Atlantic region lasting from c. 950 to c. 1250. It was likely related to warming elsewhere while some other regions were colder, such as the tropical Pacific. Average global mean temperatures have been calculated to be similar to early-mid 20th century warming. Possible causes of the Medieval Warm Period include increased solar activity, decreased volcanic activity, and changes to ocean circulation.

References

  1. ↑ Gillis, Justin (May 1, 2012). "Clouds' Effect on Climate Change Is Last Bastion for Dissenters". New York Times. Retrieved February 23, 2018. ...the Heartland Institute, the primary American organization pushing climate change skepticism...
  2. ↑ Routledge Handbook of Climate Change and Society. Routledge. 2010. p. 256. ISBN   1135998507. The Heartland Institute, a leading think-tank promoting climate change denial...
  3. ↑ Michael Mann (2013). The Hockey Stick and the Climate Wars: Dispatches from the Front Lines. Columbia University Press. p. 64. ISBN   0231152558. Many organizations have settled in the Potemkin village of climate change denial. Among them are the American Enterprise Institute...Heartland Institute
  4. ↑ James Hoggan, Richard Littlemore (2009). Climate Cover-Up: The Crusade to Deny Global Warming. Greystone Books Ltd. p. 79. ISBN   1553654854. Similarly, the Heartland Institute, a small regional think tank in the 1990s, emerged as a leading force in climate change denial in the past decade
  5. ↑ "Who We Are - Craig Loehle". Heartland Institute . Retrieved 2018-01-11.
  6. ↑ Singer, Siegfried Fred; Avery, Dennis T. (2007). Unstoppable Global Warming: Every 1,500 Years. Rowman & Littlefield Publishers. p. 81. ISBN   9780742551176.
  7. ↑ Loehle, Craig (February 1990). "A Guide to Increased Creativity in Research: Inspiration or Perspiration?". BioScience. 40 (2): 123–129. doi:10.2307/1311345.
  8. ↑ Eley, Adrian (2012). Becoming a successful early career researcher. New York, NY: Routledge. p. 16. ISBN   1-136-28529-6. OCLC   801405674.
  9. 1 2 Loehle, Craig (2007). "A 2000-Year Global Temperature Reconstruction Based on Non-Treering Proxies". Energy & Environment. SAGE Publications. 18 (7): 1049–1058. doi:10.1260/095830507782616797. ISSN   0958-305X. pdf
  10. 1 2 Mann, Michael E. (1 October 2013). The Hockey Stick and the Climate Wars: Dispatches from the Front Lines. Columbia University Press. pp. 187–188. ISBN   978-0-231-15255-6.
  11. ↑ Schmidt, Gavin (7 December 2007). "Past reconstructions: problems, pitfalls and progress". RealClimate. Retrieved 3 October 2018.
  12. ↑ Loehle, Craig; McCulloch, J. Huston (2008). "Correction to: A 2000-Year Global Temperature Reconstruction Based on Non-Tree Ring Proxies". Energy & Environment. SAGE Publications. 19 (1): 93–100. doi:10.1260/095830508783563109. ISSN   0958-305X. pdf
  13. ↑ "IPCC Fifth Assessment Report". Climate Change 2013, WG1 Chapter 5: Information from Paleoclimate Archives. 30 January 2014. pp. 409–410, 446. Retrieved 3 October 2018.
  14. ↑ Loehle, Craig (March 2014). "A minimal model for estimating climate sensitivity". Ecological Modelling. 276: 80–84. doi:10.1016/j.ecolmodel.2014.01.006.
  15. ↑ Michaels, Patrick (28 February 2014). "More Evidence for a Low Climate Sensitivity". Cato Institute. Retrieved 14 November 2014.
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