Scientists have developed complex computer models to produce climate simulations. The models produce maps that are depictions of how the world of doubled CO2 in the computer differs from the present-day world. One thing that climate models must do skillfully to get the doubled-CO2 climate right is to simulate the present climate realistically. For example, the effect of CO2 in the polar regions is largely dominated by whether there is ice and snow to melt. If there is, then we get a feedback effect, because when it melts, the darker, newly exposed surface absorbs more sunlight. The main challenge of climate modeling is getting the feedbacks right. At present, we cannot blindly rely on the results of climate models, because we are not sure about the extent or magnitude of the feedbacks. In models, the virtual world warms in response to increasing atmospheric carbon dioxide concentrations. Different models with different treatments of important feedback mechanisms give somewhat different magnitudes for the warming.

Any rational response to climate change involves first knowing what the facts and evidence are. That is the province of science. For example, how do we know the ocean is warming? We now measure the increase in ocean heat content from an array of about 4,000 autonomous floats deployed throughout the world ocean under an international program called Argo. They are programmed to rise and sink by changing their volume. This is accomplished by pumping fluid into or out of a bladder on the float. The floats store the measurements, and then, when they are on the surface, they locate by GPS and transmit the stored data via satellites to scientists. The Argo floats have revolutionized our ability to observe the oceans. Argo data are available to everyone for free in near real time. The science is never complete. There is always more to learn. But the science that we have now is already good enough to help us make wise decisions. “Everybody is entitled to his own opinions, but not to his own facts.” Sound science can inform wise policy.

Climate change is an important existential issue for our time. This book is an anthology of readings about climate change science. The rationale for writing this book is that some universities are now beginning to require all undergraduate students to take an approved climate change course. The book is for students who may lack strong mathematical backgrounds or may not have taken some science courses. It also for the general reader who wants to understand climate change science. The book has no equations and no technical jargon and no complex charts or graphs. Anyone who can read a newspaper can read this book. The book explains how the climate change issue has developed over many decades, how the science has progressed, how diplomacy has proven unable to find a means of limiting global emissions of heat-trapping substances such as carbon dioxide created by burning fossil fuels (coal, oil, and natural gas), and how the forecast of the resulting climate change has become more worrisome.

The urgency of acting to limit climate change has nothing to do with politics or economics. Instead, it arises directly from the physics and chemistry of the climate system. Carbon dioxide, once it is added to the atmosphere, will remain there a long time. Some of it will remain in the atmosphere for centuries until natural processes remove it. Thus, it will be there essentially forever, if we think in terms of the implications on human time scales. The only known way to prevent atmospheric carbon dioxide amounts from increasing further is simply to cease emitting carbon dioxide into the atmosphere. That is why acting swiftly to make large reductions in global emissions, in order to limit climate change, is urgent. Yet very little significant progress has occurred toward actually making the large cuts in global emissions of heat-trapping gases that would be needed to stabilize climate. Without drastic and rapid cuts in emissions, our children and their descendants, and ultimately all living things, will be faced with the consequences of more severe climate disruption.

The threat of climate change was already becoming clear to some climate scientists by the 1970s. However, the scientific community had not yet brought the details of this threat to the attention of the world. A towering figure in climate science, Stephen H. Schneider, 65, died after suffering a pulmonary embolism on July 19, 2010, while flying to London from a conference in Stockholm. The loss of Schneider, a professor at Stanford University, deprives the world of both an outstanding researcher and a gifted science communicator. Although his eloquent voice has now been silenced, his powerful influence on us all is indelible, and the example of the life he led will continue to be an inspiration. The effort at climate change science communication is not something novel and recent, but it has occupied many of us climate scientists for at least half a century. I also want to emphasize that climate change science communication needs to continue, because the world has not yet acted forcefully and effectively enough to limit climate change to an amount that nations of the world have agreed on.

Hillel, some 2,000 years ago, gave a brief explanation of the five books of the Torah. These books are known to Christians as the first five books of the Old Testament. Hillel said, “Treat others as you would wish them to treat you. That is the entire Torah. The rest is commentary. Now go and study.” I am certainly not Hillel, science is obviously not religion, and the IPCC reports are not the Torah. But I think the essence of the most recent IPCC report can be summarized in 12 succinct points. Here they are: It is warming. It is us. It has not stopped. The heat is mainly in the sea. Sea level is rising. Ice is shrinking. CO2 makes oceans more acidic. CO2 in the air is up 50% since the 1800s. It is now the highest in millions of years. Cumulative emissions set the warming. Reducing emissions limits the warming. Climate change will last for centuries.

Chapter 4 provides an environmental interpretation of Kant’s aesthetic and teleological theory as developed in the Critique of the Power of Judgment. To put Kant’s insights in dialogue with new contributions in climate aesthetics, I begin with Kant’s theory of the sublime. I claim that Kant’s account of the dynamical sublime has important moral and political relevance for climate philosophy despite its human-centered focus. Next, I look into Kant’s account of natural beauty, which I suggest justifies duties against environmental degradation. I also touch on Kant’s duties to love nature’s harmony and purposes in light of ecological stewardship. The chapter concludes with a look into Kantian teleology from the Critique of Judgment. I propose that teleological judgment can be used to motivate protection of non-beautiful aspects of ecosystems, especially in light of climate-related biodiversity loss.

I urge every climate change science communicator (including anyone speaking to family and friends and colleagues) to heed these warnings. Do not follow the example of the scientist who communicates all the details and background first and then announces the results and conclusions at the end. In journalism, this sin is called “burying the lead.” Avoid metric units when speaking to Americans. Avoid unfamiliar terms that always have familiar substitutes. Rather than “anthropogenic,” you could and should say “human caused.” Do not use jargon. Try to compose messages that are simple and memorable, to repeat them often, and to partner with trusted messengers. Use metaphors and other vivid imagery. If climate change is important to you, do not speak or write about it in dry and unemotional language that conveys boredom and resignation. Instead, let your passion show. Profit from opportunities to learn from expert communicators and to get useful feedback. Nobody is born knowing how to ski or drive a car. Like these skills, communication skills can be taught, developed, practiced, and improved.