The most famous graph in all of Earth science is the Keeling curve. This graph is the result of the persistence, vision, and skill of Charles David Keeling (1928–2005). It shows the results of measuring atmospheric carbon dioxide concentrations or amounts since 1958. There was no instrument to measure CO2 concentrations accurately until Keeling invented one. Keeling showed the rest of humanity that the amount of CO2 in the atmosphere can be measured accurately, that it is increasing, and that the increase is due to human causes, mainly burning fossil fuels: coal, oil, and natural gas. His attention to detail and his passion for accuracy were legendary. His measurements of atmospheric CO2 are universally acknowledged to be rock-solid. The measurements are now being carried on by other scientists, including his son, Ralph Keeling. CO2 is only part of the human-caused strengthening of the greenhouse effect. Additional strengthening is due to methane, nitrous oxide, ozone, chlorofluorocarbons, and a few other greenhouse gases, plus some small particles, called aerosols.

In Chapter 3, I argue that it is instructive to reconsider Kant’s pre-critical texts on metaphysics and natural philosophy to challenge the standard reading. These texts articulate a naturalistic, emergent, and dynamic conception of nature which undermines Kant’s usual claims to human superiority. Since dualism and anthropocentrism are largely absent in these texts and since they also encourage planetary thinking, I suggest that environmental philosophers may find an unlikely conceptual resource. As a practical implication, I review Kant’s injunction for human adaptation in the face of natural crisis. I also explore the resurgence of Kant’s pre-critical holism in the late Opus Postumum, suggesting that Kant never fully abandoned it. I conclude with a brief discussion on the influence of Kant’s holism on Goethe, Schiller, and Humboldt, which illuminates why those after Kant would find it plausible to synthesize the pre-critical view of nature with Kant’s mature aesthetic theory.

There are gases in the atmosphere – including water vapor, carbon dioxide (CO2), methane, nitrous oxide, ozone (O3), and chlorofluorocarbons (CFCs) – that act somewhat like the glass of a greenhouse. They are partially transparent to sunlight. But these same “greenhouse gases” are not transparent to the infrared radiation, or heat, that the Earth emits. They absorb some of it, and part of what they absorb is radiated back toward the surface of the Earth. The overall effect of these gases is to trap some of the heat within the atmosphere. One of the most important scientific pioneers, who did superb research and played a major role in creating the science of climate and climate change, was born more than 200 years ago. John Tyndall (1820–1893) was the first to put the concept of the greenhouse effect on a firm empirical foundation. Tyndall immediately realized the significance of his discovery for climate. He wrote that “a slight change” in the atmospheric amount of carbon dioxide or other infrared absorbing gases could have important effects on climate.

The last four remining candidates in the race for the 2016 Republican presidential nomination vehemently reject the fundamental findings of modern climate science. They tirelessly repeat climate myths, the refutations of which are easily found on websites such as www.skepticalscience.com. In order to obtain political and financial support, especially from sources allied with the fossil fuel industry, they may conclude that they must attack mainstream climate science. Yet science is the best process that humanity has developed to learn about natural laws. These laws show us that today's generation has its hands on the thermostat controlling future climate. Mother Nature, or the physical climate system, is not concerned with anybody’s values or convictions or political litmus tests. Mother Nature is concerned with natural laws. She always wins.

This Introduction specifies the book’s aims. Its main thesis is that a comprehensive examination of Kant’s texts displays the relevance of his ethical, legal, aesthetic, metaphysical, and historical ideas for environmental problems like climate change, despite the standard view of Kant as anthropocentrist, individualist, dualist, and nonconsequentialist. Doing so, the book builds a bridge between environmental philosophy and Kant studies by offering distinctly Kantian solutions to environmental problems. I begin with an overview of the tensions in these philosophical fields, emphasizing that the climate crisis exhibits the value of Kant’s philosophy for contemporary environmental problems. After providing empirical background on climate change, I indicate why philosophy matters for the crisis. A recent greening-the-canon movement in environmental philosophy nonetheless places Kant on the wayside. The Introduction also offers an overview of the chapters.

Chapter 5 aims to review the alleged limitations of Kantian nonconsequentialism and individualism for environmental ethics and climate ethics. I begin by assessing attempts by Hans Jonas to rework Kant’s categorical imperative as a principle for sustainability. After investigating recent efforts to reinterpret the supreme principle of morality as a ground of a sustainability ethic, I outline imperfect Kantian duties for sustainability with climate change in mind. I conclude by reflecting on duties in the face of political corruption. My goals are twofold. First, I argue that the default dismissal of Kantianism in climate ethics due to Kant’s individualism and nonconsequentialism is unfounded. Second, I suggest that contemporary defenders of Kantian sustainability have untapped conceptual resources in the Doctrine of Virtue and Doctrine of Right from The Metaphysics of Morals. The resources in these texts can provide solutions to unaddressed topics in the literature such as regulatory capture.

The measurements on which we base our estimates of the Earth’s global average surface temperature are contaminated by several serious sources of error. One of them is sampling error: We have not made measurements uniformly in space and time with identical instruments at identical locations on Earth over the whole 100-plus years of record. About 70% of the Earth is covered with ocean, and the Southern Hemisphere is nearly all ocean. For many years, few measurements were made at sea because people do not live there. And even within the remaining 30% that is land, there are vast areas (imagine the great ice-covered areas of Antarctica and Greenland) where very few people live and very few measurements were made until relatively recently. Satellite measurements and data from the Argo program, discussed earlier in this book, provide greatly improved ocean data. In general, the atmosphere over the land has warmed more than the atmosphere over the ocean, and largely because of this fact and the uneven distribution of land and ocean, the warming has not been the same in the two hemispheres.

Lewis Fry Richardson (1881–1953) became interested in computational mathematics while the subject was still in its infancy. He was a pioneer in numerical analysis, which for our purposes means using arithmetic intelligently to find approximate solutions to mathematical problems that are too complicated to solve exactly. He tried to work out a mathematical system for predicting the weather. He started by doing theoretical meteorology, deriving equations representing the physical laws that describe the evolution of the familiar meteorological properties such as wind, temperature, pressure, and humidity. Richardson’s first numerical weather forecast, obtained after a great deal of tedious calculating, was not very accurate. In fact, it was wildly inaccurate. But Richardson was ahead of his time. He was a visionary. In the late 1940s, a team of meteorologists and mathematicians using one of the earliest computers produced the first successful numerical weather prediction. By the 1950s, routine weather forecasts were being produced by techniques based closely on Richardson’s method.

The closing chapter of the book illustrates the practical implications of Kant’s political and legal philosophy for climate change. Texts like the Doctrine of Right and Toward Perpetual Peace are used to rethink the complex political and collective challenges of the climate crisis. These, once again, confound the individualist and nonconsequentialist standard reading of Kant. First, I argue that Kant’s state of nature theorizing leads to prescriptions that are compatible with and justify coercive domestic and international policy to address the crisis. Second, I zoom out to consider whether Kant’s political philosophy as a whole remains too conservative or outdated to provide guidance regarding deep climate adaptation, mitigation, and radical institutional reform, answering in the negative. I close by discussing political obligations owed to peoples, interpreted in the face of the Hobbesian call for a global climate leviathan.

When you communicate climate change science, be sure to include information on solutions. Nobody wants to hear about hopelessness, and in the case of climate change, there are many reasons to be hopeful. Climate change poses difficult problems and challenges, but there are lots of solutions that are both creative and practical and that can help solve the problems and overcome the challenges of climate change. There is no silver bullet that solves all the challenges of climate change, but there is lots of silver buckshot, including increased energy efficiency and energy conservation and much more use of sun, wind, and water to provide the energy the world needs. These renewable resources are widely available now and already cost-competitive with fossil fuels. Help people realize that not acting is also making a choice, one that commits future generations to serious climate change impacts. Research suggests that messages that may invoke fear or dismay are better received if they also include hopeful messages. Everything depends on what people and their governments do.

How will the growth of atmospheric concentrations of greenhouse gases affect the climate? When we try to foresee the future global climate, we are not simply extrapolating past behavior. We are using our scientific understanding of how the climate system works. Keeping that distinction in mind, then, the typical benchmark figure by which climate scientists now predict the climate will warm in response to a doubling of CO2 is a range rather than a single number. A range often quoted is 1.5 to 4.5 degrees Celsius (which is 2.7 to 8.1 degrees Fahrenheit). Not long ago, a widely quoted consensus number was the midpoint of this range, 3 degrees Celsius (which is 5.4 degrees Fahrenheit). A similar range, also often quoted, is 2 to 5 degrees Celsius (or 3.6 to 9.0 degrees Fahrenheit). There is more than one way to arrive at such a range, both from observations and from models, and the details are important to scientists doing this research. For other people, it is more important to be familiar with the approximate range, because estimates of climate sensitivity will continue to vary as more research is done.