Comparisons of Observed Paleoclimate and Model
... •Proxy reconstructions and model simulations both suggest that late 20th century warmth is anomalous in the context of the past 1000-2000 years •Primary source of differences between various reconstructions appear to be related to issues of seasonality and spatial representativeness • Important diff ...
... •Proxy reconstructions and model simulations both suggest that late 20th century warmth is anomalous in the context of the past 1000-2000 years •Primary source of differences between various reconstructions appear to be related to issues of seasonality and spatial representativeness • Important diff ...
Medieval Warm Period - Natural Climate Change
... was on the origin of the ice ages, the possibility of an imminent future ice age, and the first explorations of the so-called Little Ice Age and Medieval Warm Period. Even in the first IPCC assessment (IPCC, 1990), many climatic variations prior to the instrumental record were not that well known or ...
... was on the origin of the ice ages, the possibility of an imminent future ice age, and the first explorations of the so-called Little Ice Age and Medieval Warm Period. Even in the first IPCC assessment (IPCC, 1990), many climatic variations prior to the instrumental record were not that well known or ...
Global surface temperatures over the past two millennia
... instrumental data, (b) reliability of the low-frequency information so that millennial-scale variability can be faithfully reconstructed, and (c) adequate spatial distribution of data so that the regionally-variable nature of past climate variability [e.g., Bradley and Jones, 1993] is appropriately ...
... instrumental data, (b) reliability of the low-frequency information so that millennial-scale variability can be faithfully reconstructed, and (c) adequate spatial distribution of data so that the regionally-variable nature of past climate variability [e.g., Bradley and Jones, 1993] is appropriately ...
Lecture #1
... fossil fuel combustion (dashed line). Note that CO2 concentrations have continued to increase since 1979, despite relatively constant emissions; this is because emissions have remained substantially larger than net removal, which is primarily by ocean uptake. [From Scheraga, Joel and Irving Mintzer, ...
... fossil fuel combustion (dashed line). Note that CO2 concentrations have continued to increase since 1979, despite relatively constant emissions; this is because emissions have remained substantially larger than net removal, which is primarily by ocean uptake. [From Scheraga, Joel and Irving Mintzer, ...
climate wars, scientific evidence, and the future of homo sapiens
... The amount of time needed by a team of scientists to address a complex problem may explain the implication that climate scientists are engaged in a conspiracy, when, in fact, they are carefully carrying out a routine synthesis. After gathering scientific data, individual scientists routinely car ...
... The amount of time needed by a team of scientists to address a complex problem may explain the implication that climate scientists are engaged in a conspiracy, when, in fact, they are carefully carrying out a routine synthesis. After gathering scientific data, individual scientists routinely car ...
Non-Aerospace Research Quests of a Designer/Flight Test
... Opposite conclusion, same data, thus it might be low confidence. ...
... Opposite conclusion, same data, thus it might be low confidence. ...
IPCC_Process
... Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author and do not necessarily reflect those of the National Science Foundation. ...
... Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author and do not necessarily reflect those of the National Science Foundation. ...
biological response
... the group remained split on how certain it was that global warming caused the observed biological changes. The issue: which data should be considered Northward migration. As temperatures have warmed in Europe, the in such an analysis. Sooty copper butterfly has gone extinct in large parts of Spain a ...
... the group remained split on how certain it was that global warming caused the observed biological changes. The issue: which data should be considered Northward migration. As temperatures have warmed in Europe, the in such an analysis. Sooty copper butterfly has gone extinct in large parts of Spain a ...
Interactive comment on “Northern high
... a companion to another CPD paper that uses the described reconstruction in a datamodel comparison. Probably the most important aspect of the paper that distinguishes itself from earlier reconstructions of mid-Holocene high latitude climate is the specific use of quantitative estimates complete with ...
... a companion to another CPD paper that uses the described reconstruction in a datamodel comparison. Probably the most important aspect of the paper that distinguishes itself from earlier reconstructions of mid-Holocene high latitude climate is the specific use of quantitative estimates complete with ...
LESSONS FROM PAST GLOBAL CLIMATE CHANGES
... The Vikings colonized southern Greenland in 985 AD during the Medieval Warm Period (Lassen et al., 2004) when milder climates allowed favorable open-ocean conditions for navigation and fishing. This was "close to the maximum Medieval warming recorded in the GISP2 ice core at 975 AD (Stuiver et al., ...
... The Vikings colonized southern Greenland in 985 AD during the Medieval Warm Period (Lassen et al., 2004) when milder climates allowed favorable open-ocean conditions for navigation and fishing. This was "close to the maximum Medieval warming recorded in the GISP2 ice core at 975 AD (Stuiver et al., ...
Written Testimony - The National Academies of Sciences
... by Michael Mann, Raymond Bradley and Malcolm Hughes in 1998 and 1999. Dr. Mann and his colleagues used a new methodology to combine data from a number of sources to estimate temperatures in the Northern Hemisphere for the last six centuries, and then for the last 1,000 years. This research received ...
... by Michael Mann, Raymond Bradley and Malcolm Hughes in 1998 and 1999. Dr. Mann and his colleagues used a new methodology to combine data from a number of sources to estimate temperatures in the Northern Hemisphere for the last six centuries, and then for the last 1,000 years. This research received ...
Lab: Looking at Scientific Data on Climate Change
... one you would like to find the answer to. Write the question: Write a short summary of the answer. ...
... one you would like to find the answer to. Write the question: Write a short summary of the answer. ...
As Earth Cools, Data Centers Busy Reinventing the Past
... one in which they found relative to Parker’s findings, the height of the measurements at night was critical to the accurate assessment of minimum temperatures, something ignored in the study. Roger etal conclude: This means that a significant warm bias exists in the 2007 IPCC Report on the trends of ...
... one in which they found relative to Parker’s findings, the height of the measurements at night was critical to the accurate assessment of minimum temperatures, something ignored in the study. Roger etal conclude: This means that a significant warm bias exists in the 2007 IPCC Report on the trends of ...
The Data Behind Climate Change-
... Knowledge: Students will be able to explain climate change data and present the information to their peers. Students will analyze graphs and tables displaying past temperature changes, changes in snow covered area, global ice volume, and greenhouse gas concentrations. Students will investigate the g ...
... Knowledge: Students will be able to explain climate change data and present the information to their peers. Students will analyze graphs and tables displaying past temperature changes, changes in snow covered area, global ice volume, and greenhouse gas concentrations. Students will investigate the g ...
Shindell, DT, Schmidt, GA, Miller, R., Mann, ME, Volcanic and Solar
... •Proxy reconstructions and model simulations both suggest that late 20th century hemispheric-scale warmth is anomalous in the context of the past 1000-2000 years. Recent evidence suggests that recent warmth at more regional scales, including Europe, may be anomalous. ...
... •Proxy reconstructions and model simulations both suggest that late 20th century hemispheric-scale warmth is anomalous in the context of the past 1000-2000 years. Recent evidence suggests that recent warmth at more regional scales, including Europe, may be anomalous. ...
A report from the front lines: The Michael Mann v. National Review
... The making of a lawsuit Attacks on climate scientists get personal: 2009 University of East Anglia e-mail theft provide fodder Virginia Attorney General attempts to subpoena Prof. Mann’s e-mails and records pursuant to the Virginia Fraud Against Taxpayers Act (court rejects) to determine “whether o ...
... The making of a lawsuit Attacks on climate scientists get personal: 2009 University of East Anglia e-mail theft provide fodder Virginia Attorney General attempts to subpoena Prof. Mann’s e-mails and records pursuant to the Virginia Fraud Against Taxpayers Act (court rejects) to determine “whether o ...
How the IPCC invented a new calculus in 2010. http
... slope over 100 years. This 'proves' that global warming is accelerating. This grossly misleading calculation does not just appear in chapter 3 of WG1. It also appears in the Summary for Policymakers (SPM): "The linear warming trend over the last 50 years is nearly twice that for the last 100 years". ...
... slope over 100 years. This 'proves' that global warming is accelerating. This grossly misleading calculation does not just appear in chapter 3 of WG1. It also appears in the Summary for Policymakers (SPM): "The linear warming trend over the last 50 years is nearly twice that for the last 100 years". ...
fluid dynamics - University of Guelph
... few decades of the 20th century than during any comparable period over the preceding millennium. The substantial uncertainties currently present in the quantitative assessment of large-scale surface temperature changes prior to about A.D. 1600 lower our confidence in this conclusion compared to the ...
... few decades of the 20th century than during any comparable period over the preceding millennium. The substantial uncertainties currently present in the quantitative assessment of large-scale surface temperature changes prior to about A.D. 1600 lower our confidence in this conclusion compared to the ...
Climate Changes During the Past Millennium
... Mann, M.E., Rutherford, S., Bradley, R.S., Hughes, M.K., Keimig, F.T., Optimal Surface Temperature Reconstructions Using Terrestrial Borehole Data, Journal of Geophysical Research, 2002 (in press) ...
... Mann, M.E., Rutherford, S., Bradley, R.S., Hughes, M.K., Keimig, F.T., Optimal Surface Temperature Reconstructions Using Terrestrial Borehole Data, Journal of Geophysical Research, 2002 (in press) ...
Trump Transition Will be a Tsunami Washing Away Climate Corruption
... work with others to create the Galileo Movement, an organization that has achieved the same impact as Friends of Science. Malcolm wanted to become proactive, and as we communicated, he became aware that the real problem was in the deliberate use of bureaucrats. He learned that Maurice Strong set up ...
... work with others to create the Galileo Movement, an organization that has achieved the same impact as Friends of Science. Malcolm wanted to become proactive, and as we communicated, he became aware that the real problem was in the deliberate use of bureaucrats. He learned that Maurice Strong set up ...
17 Feb 2007
... scientists are in the reality business. Richard Alley, a lead author of the 2007 Fourth Assessment Report of the U.N.’s Intergovernmental Panel on Climate Change (IPCC), Professor of Geosciences at Penn State University, and author of a wonderful read titled “The Two-Mile Time Machine: Ice Cores, Ab ...
... scientists are in the reality business. Richard Alley, a lead author of the 2007 Fourth Assessment Report of the U.N.’s Intergovernmental Panel on Climate Change (IPCC), Professor of Geosciences at Penn State University, and author of a wonderful read titled “The Two-Mile Time Machine: Ice Cores, Ab ...
Past, Present and Future Temperatures
... Hemisphere temperature changes over the past several centuries. It was the first comprehensive study combining data from many different archives of temperature including tree rings, ice cores, and coral reefs. It demonstrated that Northern Hemisphere temperatures rose sharply during the late 20th ce ...
... Hemisphere temperature changes over the past several centuries. It was the first comprehensive study combining data from many different archives of temperature including tree rings, ice cores, and coral reefs. It demonstrated that Northern Hemisphere temperatures rose sharply during the late 20th ce ...
Behind the Hockey Stick - Page Contact:
... To construct the hockey-stick plot, Mann, Raymond S. Bradley of the University of Massachusetts Amherst and Malcolm K. Hughes of the University of Arizona analyzed paleoclimatic data sets such as those from tree rings, ice cores and coral, joining historical data with thermometer readings from the r ...
... To construct the hockey-stick plot, Mann, Raymond S. Bradley of the University of Massachusetts Amherst and Malcolm K. Hughes of the University of Arizona analyzed paleoclimatic data sets such as those from tree rings, ice cores and coral, joining historical data with thermometer readings from the r ...
Hockey stick controversy
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.The use of proxy indicators to get quantitative estimates of the temperature record of past centuries was developed from the 1990s onwards, and found indications that recent warming was exceptional. The Bradley & Jones 1993 reconstruction introduced the ""Composite Plus Scaling"" (CPS) method used by most later large-scale reconstructions, and its findings were disputed by Pat Michaels at the United States House Committee on Science.In 1998 Michael E. Mann, Raymond S. Bradley and Malcolm K. Hughes developed new statistical techniques to produce Mann, Bradley & Hughes 1998 (MBH98), the first eigenvector-based climate field reconstruction (CFR). This showed global patterns of annual surface temperature, and included a graph of average hemispheric temperatures back to 1400. In Mann, Bradley & Hughes 1999 (MBH99) the methodology was extended back to 1000. The term hockey stick was coined by the climatologist Jerry Mahlman, to describe the pattern this showed, envisaging a graph that is relatively flat to 1900 as forming an Ice hockey stick's ""shaft"", followed by a sharp increase corresponding to the ""blade"".A version of this graph was featured prominently in the 2001 IPCC Third Assessment Report (TAR), along with four other reconstructions supporting the same conclusion. The graph was publicised, and became a focus of dispute for those opposed to the strengthening scientific consensus that late 20th century warmth was exceptional.Those disputing the graph included Pat Michaels, the George C. Marshall Institute and Fred Singer. A paper by Willie Soon and Sallie Baliunas claiming greater medieval warmth was used by the Bush administration chief of staff Philip Cooney to justify altering the first Environmental Protection Agency Report on the Environment. The paper was quickly dismissed by scientists in the Soon and Baliunas controversy, but on July 28, Republican Jim Inhofe spoke in the Senate citing it to claim ""that man-made global warming is the greatest hoax ever perpetrated on the American people"".Later in 2003, a paper by Stephen McIntyre and Ross McKitrick disputing the data used in MBH98 paper was publicised by the George C. Marshall Institute and the Competitive Enterprise Institute. In 2004 Hans von Storch published criticism of the statistical techniques as tending to underplay variations in earlier parts of the graph, though this was disputed and he later accepted that the effect was very small. In 2005 McIntyre and McKitrick published criticisms of the principal components analysis methodology as used in MBH98 and MBH99. The analysis therein was subsequently disputed by published papers including Huybers 2005 and Wahl & Ammann 2007 which pointed to errors in the McIntyre and McKitrick methodology. In June 2005 Rep. Joe Barton launched what Sherwood Boehlert, chairman of the House Science Committee, called a ""misguided and illegitimate investigation"" into the data, methods and personal information of Mann, Bradley and Hughes. At Boehlert's request a panel of scientists convened by the National Research Council was set up, which reported in 2006 supporting Mann's findings with some qualifications, including agreeing that there were some statistical failings but these had little effect on the result. Barton and U.S. Rep. Ed Whitfield requested Edward Wegman to set up a team of statisticians to investigate, and they supported McIntyre and McKitrick's view that there were statistical failings, although they did not quantify whether there was any significant effect. They also produced an extensive network analysis which has been discredited by expert opinion and found to have issues of plagiarism. Arguments against the MBH studies were reintroduced as part of the Climatic Research Unit email controversy, but dismissed by eight independent investigations.More than two dozen reconstructions, using various statistical methods and combinations of proxy records, have supported the broad consensus shown in the original 1998 hockey-stick graph, with variations in how flat the pre-20th century ""shaft"" appears. The 2007 IPCC Fourth Assessment Report cited 14 reconstructions, 10 of which covered 1,000 years or longer, to support its strengthened conclusion that it was likely that Northern Hemisphere temperatures during the 20th century were the highest in at least the past 1,300 years. Over a dozen subsequent reconstructions, including Mann et al. 2008 and PAGES 2k Consortium 2013, have supported these general conclusions.