Preface

This book is an introduction to climate science for undergraduate students of both science and non-science majors and for everybody interested in the topic. It is quantitative and uses many graphs and numbers, but only a minimum amount of math is required.

Climate change is a controversial topic. You can find news and opinion articles about it on a daily basis. However, not all information is trustworthy and many articles are biased by political views and ideology (Oreskes and Conway, 2010). As a consequence of this misinformation the general public is confused and its views are quite different from those of climate scientists. Whereas almost all climate scientists think that the observed global warming over the past decades has mostly or exclusively been caused by humans (Cook et al., 2013), a view that is supported by major scientific organizations such as the National Academies of Sciences and the American Geophysical Union and my personal experiences from the scientific literature and conferences, only about half of all Americans think that way (Funk and Kennedy, 2016). I have written this book to contribute to a better informed public on this topic. My goal is to make the science accessible to everybody. For this reason the textbook is free and it includes up-to-date links to trustworthy science information.

Chapter 1 discusses differences between weather and climate and provides an introduction to the interacting components of Earth’s climate system. The following chapters 2 and 3 summarize observations of current and past changes. Chapter 4 presents theoretical foundations and discusses relevant physical processes such as electromagnetic radiation, the greenhouse effect and Earth’s energy budget. Chapters 5 and 6, which cover the carbon cycle and other processes such as atmospheric and oceanic circulations and the water cycle, provide further details on how the climate system works. Chapter 7 offers an introduction to climate models and chapter 8 discusses projections of future climate change including possible impacts on natural and human systems. Economical and ethical aspects are discussed in chapters 9 and 10. The final chapter covers possible solutions including adaptation to and mitigation of future climate change.

You will also learn some of the language climate scientists use. Highlighted words are explained in the glossary. Simply hover with the mouse over the word and a box with an explanation will appear. Exercises and questions appear in boxes such as the one below. After reading a chapter you should be able to answer the questions. Boxes are also used for some overarching concepts such as, oxygen isotopes (Chapter 3) or the budget equation (Chapter 4).

Exercises

Try it yourself and search the internet for “climate change news” or “global warming news” or similar key words and read a few (two longer or three shorter) articles or opinion pieces that sound interesting to you. You can also use an article in a paper journal or newspaper. Try to include different viewpoints and find arguments for and against human made climate change and whether or not we should do something about it.

  1. Summarize each piece in one or two paragraphs and provide the title and URL (if web source) or attach a copy (if paper source).
  2. Look for arguments that claim scientific facts or consensus and make a list of those. Be sure to include arguments both for and against human caused climate change.
  3. Indicate which arguments you think are trustworthy and why.
  4. What is your assessment of the articles? Have you learned something? Are there connections between the articles? What are the questions that remain?
  5. Beyond the above pieces, what are your personal questions about climate change?

Please write in prose (except for the list of arguments) and keep your writing to 1-2 pages of text. Please bring your writing to class for discussion and be prepared to use the arguments in a mock debate. During the class discussion we split the students in two groups, one arguing for human caused climate change and that it is a bad thing, the other arguing against human caused climate change and that it is a good thing. Two students summarize the main points made by each group on the white board. The list of topics and questions of the students will be used throughout the class attempts will be made to get back and answer them based on what we’ll learn.

It can be difficult to distinguish between trustworthy information and misinformation. Here are some general tips that may help you to separate the wheat from the chaff.
  • Trustworthy sources are the Intergovernmental Panel on Climate Change (IPCC), government agencies such as the National Oceanic and Atmospheric Administration (NOAA) and the National Aero and Space Administration (NASA), and scientific organizations such as the National Academies of Sciences, Engineering and Medicine, the American Geophysical Union (AGU), and the American Meteorological Society (AMS). The IPCC reviews the state of the science with regard to climate change every 6 years or so and summarizes the current understanding in assessment reports. The latest IPCC assessment report (AR5) was published in 2013. These reports are extensive (1,000+ pages) and a great source for scientists but not very accessible for the general public. However, the IPCC also summarizes its findings in its Summary for Policymakers, which are shorter and more accessible. I would recommend to read those. Climate scientists from around the world contribute to these reports. This textbook makes use of the IPCC reports findings and figures.
  • Articles that refer to the peer-reviewed literature and that include links or references that can be traced to the original work are preferable to articles that don’t include references. Peer-review is an important part of modern scientific practice. As part of this process the editor of a journal selects independent reviewers that are experts in the field (peers), who then read and comment on a manuscript. These comments, which are often critical and point out weaknesses or inconsistencies, are relayed back to the authors who then can revise the manuscript taking the reviewers comments into account. Only after all reviewers agree to the publication is it that in most cases the article gets published (the editor decides). Sometimes multiple revisions are necessary until all reviewers are satisfied. Reviewers examine if the conclusions of the paper are supported by evidence presented. This process is a check that improves generally the quality of the papers and makes it more difficult to publish conclusions that are not supported by evidence. But, as all human endeavors, it is not perfect.
  • Look at other articles on the same web page. If you see signs for conspiracy theories or claims that climate change is a hoax it is likely that you’re on a misleading web-page.
  • Compare the claims with trustworthy sources. If there are major discrepancies you have a reason to be doubtful.
  • Critically examine the arguments. Are they compelling? Do the authors cherry-pick data? Do they present only one side of the argument and neglect other evidence?
  • Some articles are reviewed by scientists at ClimateFeedback.org.
  • If in doubt ask a scientist. Feel free to write me or another climate scientist an email.
  • The following are websites that, in my opinion, misrepresent and/or distort climate science:
    • https://www.friendsofscience.org
    • http://climatesciencenews.com
    • https://www.climatedepot.com
    • https://wattsupwiththat.com
    • https://www.cato.org
    • http://www.aei.org
    • https://www.heartland.org
    • http://principia-scientific.org

References

Cook J., D. Nuccitelli, S. A. Green, M. Richardson, B. Winkler, R. Painting, R. Way, P. Jacobs and A. Skuce, 2013, Quantifying the consensus on anthropogenic global warming in the scientific literature, Environmental Research Letters, 8, doi:10.1088/1748-9326/8/2/024024.

Funk C. and B. Kennedy, 2016, The Politics of Climate, Chapter 1: Public views on climate change and climate scientists, Pew Research Center.

Oreskes N. and E. Conway, 2010, Merchants of Doubt, Bloomsbury Press, New York, ISBN 978-1-59691-610-4.