Mark Twain famously quipped, “Everybody talks about the weather but nobody does anything about it.”1 Now, in the twenty-first century, everyone still talks about the weather, but more and more people are talking about climate and the ways in which it is changing, with many people trying to do something about it. This book is about one option to do something about the changing climate: carbon dioxide capture and storage (CCS), or “carbon capture” for short. (In this book, I will use the terms carbon capture and CCS interchangeably.)
The burning of fossil fuels, namely coal, oil, and natural gas, releases carbon in the form of carbon dioxide (CO2). The CO2 then becomes part of the exhaust gases that go up the smokestacks of our power plants and factories, out of the tailpipes of our automobiles, and up the chimneys of our homes. These CO2 emissions are a major driver of climate change. The idea behind CCS is to “capture” the CO2 before it is released to the atmosphere. Capture technology exists today, with its roots in industrial processes that cleaned up gaseous products by removing acid gases like CO2 and SO2. The question then arises: What to do with the CO2? There are some opportunities for using it, but they are limited. As a result, most current CCS strategies call for the injection of CO2 deep underground. This forms a closed loop, where the carbon is extracted from the Earth in the form of fossil fuels and then the carbon is returned to the Earth in the form of CO2. This book will explore and explain the different options for capturing, utilizing, and storing the carbon.
I have been involved in the field of CCS for over a quarter of a century. Over that time, I have conducted research into all of the major aspects of CCS, including capture, storage, utilization, economics, policy, regulation, and public acceptance. However, I am well aware that most people have not even heard of CCS, let alone understand how it works. As part of our research at MIT, we conducted surveys of the public, where we asked the following question about a number of low carbon technologies: “Have you heard of or read about any of the following in the past year?”2 We first asked this question in 2003. For carbon capture and storage, only 4 percent of respondents said they had heard or read about it, versus 64 percent for solar energy. By 2012, these numbers had risen to 11 and 72 percent, respectively. Still, almost nine out of ten people are unaware of this major pathway for addressing climate change. For me, this has been a major motivating factor in writing this book: to help people understand what carbon capture is all about.
The first two chapters provide context for carbon capture. Chapter 1 discusses climate change; it explains the problem, outlines the possible solutions, and shows where carbon capture fits in. Chapter 2 looks at fossil fuels, which are central to both the climate change problem and the carbon capture solution. The next three chapters discuss how CCS technologies work, as well as the challenges and opportunities they face. Chapter 3 focuses on capture technology, while chapter 4 discusses what to do with the captured CO2, and chapter 5 reports on the effort to deploy CCS. Up to this point in the book, the source of the captured CO2 has been factories and power plants; chapter 6 looks at trying to capture CO2 from the air. Chapter 7 explores the policies and politics around CCS. The book then concludes by looking into the future and the role that carbon capture can play: chapter 8 shows that the more aggressively we address the climate change problem, the more important the role of carbon capture will become.