I Speak for the Trees

Brian Balogh: Hey there Backstory listeners. In honor of our ten year anniversary, Backstory is giving you all a chance to win autographed copies of our host’s most recent books. Beginning on August 17th, we’ll insert one word into ten episodes published as early as May 25th and ending September 28th. Combined, the words will form a single sentence. The first ten listeners to correctly identify and submit the sentences on or after September 28th when the last episode with a hidden word airs, will win a Virginia Humanities tote bag with signed copies of books from all four hosts, as well as additional swag from some of our sister programs. Check our website backstoryradio.org/contest for instructions on how and when to submit your entry and details on prizes. And follow Backstory on iTunes, Google Play, Spotify, or your favorite pod catcher to receive it free every week and not miss a contest episode. Happy hunting. Major funding for Back Story is provided by an anonymous donor, the National Endowment for the Humanities, The University of Virginia, and the Robert and Joseph Cornell Memorial Foundation.

Nathan Connolly: From Virginia Humanities, this is Backstory.

Joanne Freeman: Welcome to Back Story. The show that explains the history behind today’s headlines. I’m Joanne Freeman.

Brian Balogh: I’m Brian Balogh.

Nathan Connolly: And I’m Nathan Connolly.

Reporters: New findings on the effect of climate change in the U.S.

Reporters: A report obtained by the New York Times found the average temperature in the U.S. has gone up rapidly since 1980.

Reporters: But, scientists say it’s more than temperatures. They have connected man made climate change to deadly heat waves, droughts, and devastating floods.

Reporters: Now, the study by scientists from 13 federal agencies directly contradicts claims by the president and some cabinet officials who say that human contribution to climate change is uncertain.

Brian Balogh: This summer has been brutally hot. So hot in fact it’s the fourth warmest summer ever worldwide in all of recorded history. Since the late 19th century, the earth’s average temperature has risen about two degrees. Most of that rise comes from increased carbon dioxide emissions into the atmosphere. Now two degrees might not sound like much, but scientists fear that those rising temperatures could produce even more extreme weather, famines and millions of climate refugees.

Nathan Connolly: Americans have long been fascinated by climate patterns and how those patterns affect their lives. At the dawn of the republic, concerns about the climate were also concerns about national security. Historian Joyce Chaplin says lots of folks, including the founding fathers, debated about how to deal with the young nation’s harsh climate.

Joyce Chaplin: Being scientifically literate was culturally important during this period of time and you weren’t really a well-educated person unless you knew some science.

Nathan Connolly: Is there an earlier version of a climate debate happening among the founders in this period?

Joyce Chaplin: That’s what’s really interesting about this period is that not only were there now theories of climate being complex, but there are also complexities within the argument about it. So there was not one theory, there was not one opinion. There was a big interesting argument about it all.

Nathan Connolly: So, the most popular theory, which originated in Europe, suggested that cutting down trees would produce warmer, more comfortable temperatures.

Joyce Chaplin: They were convinced that forests, too many trees, actually shaded the earth from the sun. Land that had been overgrown with weeds and wild vegetation, if it were cleared and planted with crops, and all that land turned up with hoes or plows, that also would have a warming effect on the climate. And so we also see coming into focus a sense of antipyogenic climate change. What humans do affects the climate. The idea that humans on a large scale could transform the average temperature for entire regions if not continents was quite new, and yet this is what settlers in North American start talking about doing.

Nathan Connolly: This idea was actively promoted by science nerd turned US president, Thomas Jefferson.

Joyce Chaplin: So, Jefferson was an advocate or a proponent for clearing land, bringing it onto cultivation through European style agriculture, and in some ways, this is a criticism of the indigenous inhabitants whom he thought had not brought enough of the land under cultivation and that therefore the country was cooler than it actually needed to be.

Nathan Connolly: So given these ideas about the link between deforestation and climate change being bandied about, did people actually deforest on a mass scale to bring about these ends?

Joyce Chaplin: The deforestation took place on a mass scale, whether people were really doing it to make the weather warmer or not. It just happened because a lot of settlers were moving across land and taking down forests in order to create farmland. It’s true that into the 19th century there was this other belief that land that was cleared would bring rain. So when people moved out into the Great Plains area, where there had been historic droughts, there was nevertheless a believe that rain follows the plow, that once lands are brought under cultivation the rain would come.

Nathan Connolly: So the plow comes first, then the cloud comes after. Wow. That’s something.

Joyce Chaplin: Yes, exactly. And only after several terrible droughts and people failing, was there a kind of concession that maybe not.

Nathan Connolly: While Jefferson and others were actively trying to warm things up. America’s leading scientists felt cutting down all the trees was a terrible plan.

Joyce Chaplin: So Benjamin Franklin warned that taking down all the trees are too many trees might make the summers unbearably hot. So be careful, and be careful what you wish for that if you really, really want a warm climate, fine, but having a climate that was going to be too hot was not going to be good.

Nathan Connolly: Franklin who had been studying climate fluctuations for while, started by printing daily weather reports in his newspaper and in Poor Richard’s Almanac.

Joyce Chaplin: Where very conventionally he reports on what the average temperatures were supposed to be, what the prevailing conditions, kind of odd weather events, storms, significant changes in weather and unexpected patterns. And these include the freezing over of Boston Harbor, really bad winter weather that begin to intrigue him because he starts tying them back into a theory that these were not just stray events, but part of a longer term shift.

Nathan Connolly: And then trying to make sense of that shift, Franklin collected data on a grander scale.

Joyce Chaplin: Franklin does study heat and weather in a lot of parts of the world, so eventually he makes observations about medieval Europe, different parts of the Americas, even as far away as Russia. So he really is aware of how global climates operated in contrast to each other and how specific weather patterns were particular to different parts of the world. So in some ways he has a bigger geography that he comments on, than perhaps Jefferson was doing in relation to Virginia and two parts of North America and the United States specifically.

Nathan Connolly: Benjamin Franklin’s interest in patterns of hot and cold lead him to a more sophisticated understanding of the climate itself.

Joyce Chaplin: And in this way he contributes to earlier theorization about atmospheric circulation and oceanic circulation. How it is that patterns of hot and cold move over hemispheres, over continents and oceans. He describes, for instance, the circulation of hot air out of the Gulf of Mexico, up the continent and eventually across the Atlantic Ocean, and he connects us to the phenomenon that we now call the gold stream. So that sense of circulation and have a kind of irregular pattern of heat and cold moving north and south as well as east and west, that was one of the biggest challenges to this old idea of climate as latitude.

Nathan Connolly: Now, we use an idea today of something called a little ice age. They might not have used that language back then, but they certainly were aware that there were things happening kind of across many different generations that were reflecting changes in the environment. Is there a sense that the ice age or the kind of long period of cold that the founders were considering and that Jefferson and Franklin were debating, that, that has come to some kind of end.

Joyce Chaplin: I gather from geologists that we’re not sure it’s over. We could still be in a period of global cooling, but we have forced the climate to be warmer and that’s overriding the cooler stage that we would be in otherwise, which is kind of terrifying to think about that it would be even hotter. What we’re doing in terms of forcing carbon to the atmosphere would make things even hotter than it would be if we didn’t have this period of global cooling that’s still going on. It does seem that the little ice age, the conditions that were described from the late middle ages into the colonial period was feeding over the course of the 19th century. We think it was still operating when Napoleon’s troops marched out of Moscow in much colder weather than they had anticipated. It may still have been operating into the 1840s and up to perhaps about 1850. For the second half of the 19th century though, all of the components of the little ice age, extreme weather condition, longer winters, freezing over bodies of water, those stopped being commented on and we’ve entered a new age.

Nathan Connolly: So Joyce, can you give me any sense of what native Americans might have thought about the little ice age? Do we even know?

Joyce Chaplin: Oh, I wish we knew more, and we need to know more. And this will require a lot of experts in indigenous languages and archeology to really expand our understanding, because without that we actually don’t know a lot about how human adaptation to climates in North America would have worked before 1492, and it’s really essential that we do that.

Brian Balogh: In the way that the founders observed and debated the nature of climate change and human activity, are there any lessons from that, that we could point to and draw from today?

Joyce Chaplin: I guess I’m always skeptical about the claim that anything that happens now is historically unprecedented because in some sense that’s self-congratulatory. Everything new happens to us. Whatever we are undergoing now or talking about now has never happened to anyone in the world ever before. Well maybe so, but I think we want to eliminate the possibility that actually it’s happened before. Yes, we may be living within something unprecedented in terms of anthropogenic climate change that we have done it, but we’re not the first people to live in a period of rapid or dramatic climate change, and looking at everyone who has done that before could be incredibly useful for us.

Nathan Connolly: Joyce chaplain is a professor of history at Harvard University and author of The First Scientific American: Benjamin Franklin and the pursuit of genius.