Climate Change Reconsidered

First Volume (2009)


This 880-page rebuttal of the Fourth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC), three years in the making, was released in June 2009 by The Heartland Institute. Coauthored and edited by S. Fred Singer, Ph.D., and Craig Idso, Ph.D. and produced with contributions and reviews by an international coalition of scientists, it provides an independent examination of the evidence available on the causes and consequences of climate change in the published, peer-reviewed literature examined without bias and selectivity. It includes many research papers ignored by the IPCC plus additional scientific results that became available after the IPCC deadline of May 2006.

Click here for free PDFs of the entire book or individual chapters.

Chapter 1 describes the limitations of the IPCC s attempt to forecast future climate with computer models. The IPCC violates many of the rules and procedures required for scientific forecasting, making its projections of little use to policymakers.

Chapter 2 describes feedback factors that reduce the earth s sensitivity to changes in atmospheric CO2. Scientific studies suggest the model-derived temperature sensitivity of the earth for a doubling of the pre-industrial CO2 level is much lower than the IPCC s estimate.

Chapter 3 reviews empirical data on past temperatures. We find no support for the IPCC s claim that climate observations during the twentieth century are unprecedented or provide evidence of an anthropogenic effect on climate.

Chapter 4 reviews observational data on glacier melting, sea ice area, variation in precipitation, and sea level rise. We find no evidence of trends that could be attributed to the supposedly anthropogenic global warming of the twentieth century.

Chapter 5 summarizes the research of a growing number of scientists who say variations in solar activity, not greenhouse gases, are the true driver of climate change. We describe the evidence of a solar-climate.

Chapter 6 investigates and debunks the widespread fears that global warming might cause more extreme weather. The IPCC claims global warming will cause (or already is causing) more droughts, floods, hurricanes, storms, storm surges, heat waves, and wildfires. We find little or no support in the peer-reviewed literature for these predictions and considerable evidence to support an opposite prediction: That weather would be less extreme in a warmer world.

Chapter 7 examines the biological effects of rising CO2 concentrations and warmer temperatures. This is the largely unreported side of the global warming debate, perhaps because it is unequivocally good news. Rising CO2 levels increase plant growth and make plants more resistant to drought and pests. It is a boon to the world s forests and prairies, as well as to farmers and ranchers and the growing populations of the developing world.

Chapter 8 examines the IPCC s claim that CO2-induced increases in air temperature will cause unprecedented plant and animal extinctions, both on land and in the world s oceans. We find there little real-world evidence in support of such claims and an abundance of counter evidence that suggests ecosystem biodiversity will increase in a warmer and CO2-enriched world.

Chapter 9 challenges the IPCC s claim that CO2-induced global warming is harmful to human health. The IPCC blames high-temperature events for increasing the number of cardiovascular-related deaths, enhancing respiratory problems, and fueling a more rapid and widespread distribution of deadly infectious diseases, such as malaria, dengue and yellow fever. The peer-reviewed scientific literature reveals that further global warming would likely do just the opposite and actually reduce the number of lives lost to extreme thermal conditions.

Interim Report (2011)


The United Nations’ Intergovernmental Panel on Climate Change (IPCC), already under severe criticism for violating the requirements of academic peer review and relying on secondary sources, comes under attack again in a new report co-produced by three nonprofit research organizations.

According to the new report, “natural causes are very likely to be [the] dominant” cause of climate change that took place in the twentieth and at the start of the twenty-first centuries. “We are not saying anthropogenic greenhouse gases (GHG) cannot produce some warming or have not in the past. Our conclusion is that the evidence shows they are not playing a substantial role.”

The authors of the new report go on to say “the net effect of continued warming and rising carbon dioxide concentrations in the atmosphere is most likely to be beneficial to humans, plants, and wildlife.”

Both conclusions contradict the findings of the widely cited reports of the IPCC.

Click here for free PDFs of the entire book or individual chapters.

The report was produced by The Heartland InstituteCenter for the Study of Carbon Dioxide and Global Change, and Science and Environmental Policy Project (SEPP), three national nonprofit organizations based in Chicago, Illinois; Tempe, Arizona; and Arlington, Virginia; respectively.

The 430-page report was coauthored and edited by three climate science researchers: Craig D. Idso, Ph.D., editor of the online magazine CO2 Science and author of several books and scholarly articles on the effects of carbon dioxide on plant and animal life; Robert M. Carter, Ph.D., a marine geologist and research professor at James Cook University in Queensland, Australia; and S. Fred Singer, Ph.D., a distinguished atmospheric physicist and first director of the U.S. Weather Satellite Service. Seven additional scientists and one policy expert on sustainable growth made contributions to the volume.

CCR2-Cover2-790x1024Second Volume, Part 1 (2013)


Climate Change Reconsidered II: Physical Science is an independent, comprehensive, and authoritative report on the current state of climate science. It is the fourth in a series of scholarly reports produced by the Nongovernmental International Panel on Climate Change (NIPCC), an international network of climate scientists sponsored by three nonprofit organizations: Center for the Study of Carbon Dioxide and Global ChangeScience and Environmental Policy Project (SEPP), and The Heartland Institute.

Previous volumes in the Climate Change Reconsidered series were published in 20082009, and 2011. Those volumes along with separate executive summaries for the second and third reports are available for free online on this site.

Whereas the reports of the United Nations’ Intergovernmental Panel on Climate Change (IPCC) warn of a dangerous human effect on climate, NIPCC concludes the human effect is likely to be small relative to natural variability, and whatever small warming is likely to occur will produce benefits as well as costs.

CCR-II consists of three parts: Part One titled Physical Science, Part Two titled Biological Impacts, and Part Three titled Human Welfare, Energy, and Policies. Part One was released on September 17-18, 2013 in Chicago, Illinois USA. Additional release events took place the following weeks in Washington, DC, New York, Florida, St. Louis, England, Germany, Holland, and California. Part Two was released on March 31, 2014. Part Three will be released in June.

CCR2b Cover-hi res-032814Second Volume, Part 2 (2014)


Climate Change Reconsidered II: Biological Impacts constitutes an independent, comprehensive, and authoritative report on the impacts of climate change on plants, terrestrial animals, aquatic life, and human well-being. Climate Change Reconsidered II: Human Welfare, Energy, and Policies will use economics and policy analysis to explain the implications of climate change on energy production and consumption and a wide range of public policies.

These two volumes are the fifth and sixth in a series of scholarly reports produced by the Nongovernmental International Panel on Climate Change (NIPCC), an international network of climate scientists sponsored by three nonprofit organizations: Center for the Study of Carbon Dioxide and Global Change, Science and Environmental Policy Project (SEPP), and The Heartland Institute. Previous volumes in the Climate Change Reconsidered series were published in 200820092011, and 2013. Those volumes along with separate executive summaries for the second, third, and fourth reports are available for free online on this site.

Whereas the reports of the United Nations’ Intergovernmental Panel on Climate Change (IPCC) warn of a dangerous human effect on climate, NIPCC concludes the human effect is likely to be small relative to natural variability, and whatever small warming is likely to occur will produce benefits as well as costs.

 Praise for the Climate Change Reconsidered series

“From the perspective of the International Climate Science Coalition, this book, Climate Change Reconsidered: 2011 Interim Report of the Nongovernmental International Panel on Climate Change is worth far more than its weight in gold.

“The value of this document is that it really has two parts — one, a brief introduction at the beginning of each chapter that anyone, even people untrained in the field, can quickly read to understand, in general terms, where official climate science is off base. The second part of each chapter goes through the evidence for each introduction.

“No one anywhere in the world has ever produced a document of this nature that is so easy to read, directly applicable to today’s most discussed topics, and yet so extensively referenced.

“While it is worthwhile to read the whole report, of course, reporters and government officials need to at least read the introductions to get a handle on what the UN IPCC has done wrong or misrepresents.

“History will record the NIPCC as the most significant contribution any person or group on the climate realist side of the debate made to helping society get back on track towards making climate and energy decisions that actually help the environment and society.”

– Tom Harris, executive director, International Climate Science Coalition

“As the old proverb has it, people in glass houses should be very careful about throwing stones. We’ve been told many times that the regular IPCC reports represent a clear consensus of the Scientific Community on the issue, and are based solely on peer-reviewed science. If only.

“As we’ve seen over the last couple of years, many of the more outlandish and alarmist claims in the IPCC reports have been based not on peer-reviewed science, but on ‘grey literature’ — the propaganda sheets and press releases distributed by fanatical green NGOs (many of which are part-funded by the European Commission — but that’s another story).

“But for those who prefer their science hard-core, not populist, hope is at hand. Indeed it’s been at hand for some time, in the form of the NIPCC (Nongovernmental International Panel on Climate Change) Report. First published in 2009, we now have the updated 2011 Interim Report, published by the Heartland Institute (whose conferences I have been privileged to attend). …

“Given the increasing realisation that climate mitigation efforts are creating an economic crisis, and increasing popular scepticism about the alarmist scenario, this is a timely publication, and a key resource for all of us who are arguing for common sense.”

– Roger Helmer, MEP, MA, a member of the European Parliament representing
the UK’s East Midlands Region for the Conservative Party.

“The 2011 edition of Climate Change Reconsidered is a quite extraordinary achievement. It should put to rest once and for all any notion that “the science is settled” on the subject of global warming, or that humanity and our planet face an imminent manmade climate change disaster. …

“In short, Climate Change Reconsidered is a thoughtful, thought-provoking, cool-headed antidote to the alarmism that has been driving far too many policies, laws, regulations and other decisions all over the world in recent years. It underscores the ‘precautionary principle’ that SHOULD be applied here: Climate alarmists must prove, with clear and convincing evidence, that we face an imminent manmade climate disaster, and that their “solutions” will avert that disaster, without creating even bigger problems – before any such prescriptions are implemented. They have a long way to go to make that case.”

– Paul Dreissen, senior fellow with the Committee For A Constructive Tomorrow,
BA in geology and ecology, JD in environment and natural resource law.

Among its other achievements, CLIMATE CHANGE RECONSIDERED helps to re-establish the connection between Earth’s environment and extraterrestrial influences, including cosmic rays. Of course, the authors also discuss the effects of terrestrial factors such as CO2 levels, cloud cover and rainfall. Their scholarly analysis brings some much-needed realism (and good old-fashioned common sense) to the climate change debate. Highly informative, CLIMATE CHANGE RECONSIDERED ought to be required reading for scientists, journalists, policymakers, teachers and students. It is an eye-opening read for everyone else (concerned citizens, taxpayers, etc.). In short … this book is highly recommended!

– William Mellberg

“The NIPCC report, Climate Change Reconsidered, is not just an attempt to refute the IPCC, but a volume that fills in the gaps left by the IPCC fourth assessemt report (FAR). With it’s emphasis on natural variability as a cause for the recent climate changes, it is a must have for serious climate scientists who should not just rely on the IPCC FAR alone to get the full picture of our current state of knowledge (and what is not known) about climate and climate change. Dr. S. Fred Singer and Dr. Craig Idso have done a thorough job in providing climate science with this volume and should be commended for their effort.”

– Anthony R. Lupo, associate professor of atmospheric sciences in the Soil, Environmental,
and Atmospheric Sciences Department at the University of Missouri -Columbia.

“I’ve been waiting for this book for twenty years. It was a long wait, but I’m not disappointed.

Climate Change Reconsidered is a tour de force. It takes on all the alleged evidences of catastrophic, manmade global warming and demonstrates, patiently and clearly, why they fail to support the conclusion. Its 2 authors and 35 contributors are outstanding scientists with unassailable credentials — a fact that, unfortunately, won’t stop movement alarmists from their customary ad hominem attacks. The book is chock full of excellent data, analysis, and argumentation, sophisticated enough to meet the demands of any expert, yet clearly enough written to be accessible to laymen. …

“And for those who want to just write it off by attacking its authors, it’s time to engage the real arguments for a change. The time for personal attack is over..”

– E. Calvin Beisner, The Cornwall Alliance

“I fully support the efforts of the Nongovernmental International Panel on Climate Change (NIPCC) and publication of its latest report, Climate Change Reconsidered II: Physical Science, to help the general public to understand the reality of global climate change.”

-- Kumar Raina, Former Deputy Director General, Geological Survey of India

“I was glad to see that a new report was coming from the NIPCC. The work of this group of scientists to present the evidence for natural climate warming and climate change is an essential  counter-balance to the biased reporting of the IPCC. They have brought to focus a range of peer-reviewed publications showing that natural forces have in the past and continue today to dominate the climate signal. Considering the recent evidence that climate models have failed to predict the flattening of the global temperature curve, and that global warming seems to have ended some 15 years ago, the work of the NIPCC is particularly important.”

– Ian Clark, Department of Earth Sciences, University of Ottawa, Canada

“The CCR-II report correctly explains that most of the reports on global warming and its impacts on sea-level rise, ice melts, glacial retreats, impact on crop production, extreme weather events, rainfall changes, etc. have not properly considered factors such as physical impacts of human activities, natural variability in climate, lopsided models used in the prediction of production estimates, etc.  There is a need to look into these phenomena at local and regional scales before sensationalization of global warming-related studies.”

– S. Jeevananda Reddy, Former Chief Technical Advisor, United Nations World Meteorological Organization

“NIPCC’s CCR-II report should open the eyes of world leaders who have fallen prey to the scandalous climate dictates  by the IPCC. People are already suffering the consequences of sub-prime financial instruments. Let them not suffer more from IPCC’s sub-prime climate science and models. That is the stark message of the NIPCC’s CCR-II report.”

M. I. Bhat, Formerly Professor and Head, Department of Geology and Geophysics, University of Kashmir

“The claim by the UN IPCC that ‘global sea level is rising at an enhanced rate and swamping tropical coral atolls’ does NOT agree with observational facts, and must hence be discarded as a serious disinformation. This is well taken in the CCR-II report.”

Nils-Axel Mörner, Emeritus Professor of Paleogeophysics & Geodynamics, Stockholm University, Sweden

“Library shelves are cluttered with books on global warming. The problem is identifying which ones are worth reading. The NIPCC’s CCR-II report is one of these. Its coverage of the topic is comprehensive without being superficial. Itsorts through conflicting claims made by scientists and highlights mounting evidence that climate sensitivity to carbon dioxide increase is lower than climate models have until now assumed.”

– Chris de Freitas, School of Environment, The University of Auckland, New Zealand

Climate Change Reconsidered is simply the most comprehensive documentation of the case against climate alarmism ever produced. Basing policy on the scientifically incomplete and internally inconsistent reports of the UN’s Intergovernmental Panel on Climate Change is no longer controversial – Climate Change Reconsidered shows that it is absolutely foolhardy, and anyone doing so is risking humiliation. It is a must-read for anyone who is accountable to the public, and it needs to be taken very, very seriously.”

– Patrick J. Michaels, Director, Center for the Study of Science, Cato Institute

“CCR-II provides scientists, policy makers and other interested parties information related to the current state of knowledge in atmospheric studies.  Rather than coming from a pre-determined politicized position that is typical of the IPCC, the NIPCC constrains itself to the scientific process so as to provide objective information.  If we (scientists) are honest, we understand that the study of atmospheric processes/dynamics is in its infancy.  Consequently, the work of the NIPCC and its most recent report is very important.  It is time to move away from politicized science back to science – this is what NIPCC is demonstrating by example.”

– Bruce Borders, Professor of Forest Biometrics, Warnell School of Forestry and Natural Resources, University of Georgia

“The NIPCC’s new report, Climate Change Reconsidered II: Physical Science, fires a scientific cannon shot across the bow of the quasi-religious human-caused global warming movement by presenting data, facts, and scientific method constructs of climate change science. I only wish the IPCC would become as objective. A recent column by a nationally recognized writer recalled Syria outlawing yo-yos in 1933 because they thought that yo-yo motion caused drought. The NIPCC report documents that the AGW movement has created its own yo-yo rather than shedding light on how Earth dynamic systems change with time.  I applaud the NIPCC for bringing the scientific method back into what should always have been a scientific debate.

– Lee C. Gerhard, Senior Scientist Emeritus, University of Kansas, Past Director and State Geologist,  Kansas Geological Survey

“I support [the work of the NIPCC] because I am convinced that the  whole field of climate and climate change urgently needs an open debate between  several ‘schools of thought,’ in science and well as other disciplines , many of which  jumped on the IPCC bandwagon far too readily. Climate, and even more  so impacts and responses, are far too complex and important to be left to an official body like the IPCC.”

– Sonja A.Boehmer-Christiansen, Reader Emeritus, Department of Geography, Hull University, Editor, Energy & Environment

“The NIPCC report Climate Change Reconsidered II is a crucial document to get science right: Billions of $$ are being spent in research based on the assumption that human emissions of CO2 drive dangerous climate change. Contemplating relevant peer-reviewed scientific literature, the CCR-II shows us why this basic assumption is wrong, turning irrelevant for society the results of a considerable part of the costly research carried out by the ‘consensus scientific community’ endorsing IPCC climate alarmism.”

– Albrecht Glatzle, Agro-Biologist, Retired Director of Research, INTTAS

(Read a collection of reviews here and here.)