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About this course

12.340x introduces the basic science underpinning our knowledge of the climate system, how climate has changed in the past, and how it may change in the future. The course focuses on the fundamental energy balance in the climate system, between incoming solar radiation and outgoing infrared radiation, and how this balance is affected by greenhouse gases. We will also discuss physical processes that shape the climate, such as atmospheric and oceanic convection and large-scale circulation, solar variability, orbital mechanics, and aerosols, as well as the evidence for past and present climate change. We will discuss climate models of varying degrees of complexity, and you will be able to run a model of a single column of the Earth's atmosphere, which includes many of the important elements of simulating climate change. Together, this range of topics forms the scientific basis for our understanding of anthropogenic (human-influenced) climate change.

We will not cover issues regarding policy responses to climate change. Rather, Global Warming Science is designed to be a strictly scientific introduction to this important topic.

Course structure

The course is divided into 12 weekly sections which will be released sequentially. Each section includes a set of lecture videos, often accompanied by practice problems. Although these practice problems are ungraded, students are expected to work through them, as they are designed to check your understanding of the lecture material. Additional background readings may be assigned, all of which are sourced from material freely available online. Links to these readings will be provided on the introductory page of each section.

The course will be graded based on weekly online problem sets, as well as an online final exam. Each problem set will become available 2 days after the release of the corresponding lecture videos, and will be due 1 week after the date on which it is released. The only exception is the introductory problem set, which is relatively short, and will therefore be due 6 days after it is released. Due dates for each section's problem sets can be seen in the left-hand navigation bar, under the names of their respective sections.

Please note that all release times and due dates use Coordinated Universal Time (UTC). The current time is

See the below calendar for specific information on the scheduling of the course.


Students' grades will be based on 11 weekly problem sets and the final exam.

Each week's worth of course material will contain a problem set, which is released 2 days after the release of the lecture videos. Students will have one week to complete each problem set. Although the total number of points in each problem set may differ from week to week, each problem set will be weighted equally, with the exception of the introductory (Week 1) problem set, which is given one-half the weight of each of the remaining 10 problem sets. In total, the 11 problem sets will make up 60% of each student's grade for the course.

The final exam will account for 40% of each student's grade, and will be administered between May 11, 2014 at 3:00 UTC and May 14, 2014 at 15:00 UTC. The exam is designed to take 3 hours. Please allot yourself an adequate amount of time to complete the exam during the 48 hours in which it will be available. The exam is designed to be an individual assessment, and therefore the discussion forum will be unavailable during its administration.

A grade of 60% or higher for the entire course constitutes a passing grade. You can check your current grade status under the 'Progress' tab above.

Collaboration guidelines

We suggest that you use the guidelines below for acceptable collaboration in 12.340x. The staff will be proactive in removing posts and replies in the discussion forum that have violated these guidelines.

  • Given a problem, it is okay to discuss the general approach to solving the problem.
  • Students can work jointly to come up with the general steps for the solution.
  • It is okay to get a hint (or several hints for that matter) if you get stuck while solving a problem.
  • Students are expected to work out the details of each solution independently.
  • It is not okay to submit the answers from someone else’s solution as your own.
  • It is not okay to take someone else’s formula and plug in your own numbers to get the final answer.
  • It is not okay to post answers to problems before the submission deadline.
  • It is not okay to look at a full step-by-step solution to a problem before the submission deadline.
  • It is okay to have someone show you a few steps of a solution where you have been stuck for a while (provided, of course, that you have attempted to solve it yourself without success).
  • After you have collaborated with others in generating a correct solution, a good test to see if you were engaged in acceptable collaboration is to make sure that you are able to do the problem on your own.

Discussion forum

The discussion forum is the main way for you to communicate with the course team and other students. We hope it contributes to a sense of community and serves as a useful resource for your learning.

  • Observe the honor code. We encourage collaboration and help, but please avoid asking for and posting blatant answers. Those caught cheating may have their accounts disabled and their progress erased.
  • Be polite. We have learners from all around the world and with different backgrounds. Something that is easy for you may be challenging for someone else. Let’s build an encouraging community.
  • Upvote good posts. This applies to questions and answers. Click on the green plus button so that good posts can be found more easily.
  • Search before asking. The forum can become hard to use if there are too many threads, and good discussions happen when people participate in the same thread. Before asking a question, use the search feature by clicking on the magnifying glass on the left-hand side.
  • Notify staff. If you want to have a staff member look at your post, please write [Staff] at the start of your title.
  • Be specific. Choose a descriptive title, and provide as much information as possible: Which part of what problem or video? Why do you not understand the question? What have you tried doing?
  • Write clearly. We know that English is a second language for many of you but correct grammar will help others to respond. Avoid ALL CAPS, abbrv of wrds (abbreviating words), and excessive punctuation!!!!
  • Use discussion while working through the material. On many pages in the learning sequences and homework, there is a link at the bottom that says “Show Discussion”. Clicking on this link will show all discussion on the forum associated with this particular learning material.
  • This course deals strictly with the science of global warming, and will not cover issues regarding policy responses to climate change. As such, to avoid political debates, any discussion post regarding policy issues will be removed.
  • Repeated, intentional, or malicious violation of the above guidelines may result in a student's ejection from the course.

Course calendar, Spring 2014

Week # Topic Release date* Problem set release date* Problem set due date*
Part I: Introduction and history of the Earth's climate
1 Introduction to the course February 19 February 21 February 27
2 A little climate physics February 25 February 27 March 6
3 Paleoclimate March 4 March 6 March 13
4 Instrumental record of the Earth's climate;
Composition of the atmosphere
March 11 March 13 March 20
Part II: Basic climate physics
5 Radiative heat transfer March 18 March 20 March 27
6 Convective heat transfer and radiative-convective equilibrium March 25 March 27 April 3
7 Atmospheric circulation April 1 April 3 April 10
8 Clouds, aerosols, and climate April 8 April 10 April 17
9 Oceans and climate April 15 April 17 April 24
10 The carbon cycle and geochemistry of radiatively active trace gases April 22 April 24 May 1
Part III: The global climate system and climate modeling
11 Forcings and feedbacks in the climate system April 29 May 1 May 8
12 Climate modeling May 6 None None
Final Exam: May 11 (3:00 UTC) - May 14 (15:00 UTC)
*All release and due dates refer to 15:00 UTC on the date specified, unless otherwise noted.