The numbers had already left impressionable marks on me, and as they swirled in my head for some months I certainly had a sense for the urgent warning they wanted me to hear. But it wasn’t until I rubbed the numbers together that the message really rang out. Then plotting the historical evolution shook me anew. I was staring at the ecological cliff we appear to be driving over.
Let’s build the punchline from a few facts that were already rattling around in my head. Human population, at 8 billion today, was 1 billion around the year 1800. At a global average human mass of 50 kg, that’s 400 Mt (megatons) of humans—matching the 390 Mt I had seen in a superb graphic from Greenspoon et al., shown later in this post. This same graphic shows wild land mammal mass at 20 Mt today. I also knew that wild land mammal mass was about 4 times higher in 1800, and 5 times higher 10,000 years ago.
Put these together, and what do you get? In 1800, every human on the planet had a corresponding 80 kg of mammal mass in the wild. Wild land mammals outweighed humans in an 80:50 ratio.
Today, each human on the planet can only point to 2.5 kg of wild mammal mass as their “own.”
Let that sink in. You only have 2.5 kg (less than 6 pounds) of wild mammal out there somewhere. A single pet cat or dog generally weighs more. Not that long ago, it was more than you could carry. Now, it seems like hardly anything! I especially fear the implications for mammals should global food distribution be severely crippled.
The graph is even more alarming to me.
Mass ratio (left axis) and total mass (right axis) of wild land mammal mass per person on the planet. Note the logarithmic vertical axis, as is necessary to show the wide range of values.
The vertical scale is logarithmic in order to show the enormous range involved. The precipitous drop in the present age is staggering. How can we look at this and think that we’re heading in the right direction? That’s modernity for you, folks.
You may be familiar with the term “hockey stick curve,” used describe a trend that has been flat/stable for a very long time, but shoots up at the end of the series in dramatic fashion, resembling the shape of a hockey stick. Hockey can be a violent sport, and it’s easy to get hurt by even one well-aimed swing. Today’s world is being battered from all sides by countless hockey sticks. Mostly, they seem to be targeting Earth’s critters, who are getting bludgeoned unsparingly. But in the end, we’re only harming ourselves.
This post is structured as a gauntlet of hockey stick curves that may leave the reader feeling a bit bruised. Depending on what’s being plotted, many of the graphs shoot up like an exponential, but a few are careening downwards. A theme emerges: the “bads” go up, and the “goods” go down—and not by coincidence.
For some light summer amusement, I thought I would share a map I made a while back to satisfy my curiosity. I’ve had the plot in my office for several years and occasionally think to pull it out for visitors I suspect will enjoy it. I usually just hand it to them and let them puzzle over its meaning before I explain anything. It’s not meant to be an IQ test—although doubtless some feel that way—but rather a chance to delight in self discovery. I “discovered” the 7-24-25 Pythagorean triangle the other day quite by accident while constructing a relativity problem and was delighted by the find—even though Wikipedia has an exhaustive list of other sets wholly unknown to me. Likewise, I “discovered” Saturn as a 15-year-old on a summer night with a small telescope just poking around an unfamiliar sky. I danced around the yard in delight. My point is that discovery is personal, even if not original.
So here’s a chance to discover what the map is meant to convey. I’ll naturally explain later.
I have not kept it secret that I’m a fan of solar power. Leaving storage hangups aside for now, the fact that the scale of available power is comfortably gigantic, that perfectly efficient technology exists, that it’s hard-over on the reality axis (vs. fantasy: it’s producing electricity on my roof right now), and that it works well almost everywhere—what’s not to like? Did you trip over that last part? Many do. In this post, we’ll look at just how much solar yield one may expect as a function of location within the U.S.
The ancient Mayans laboriously accumulated a substantial set of observational data on solar illumination across America well ahead of the present need. Okay, it wasn’t actually the ancient Mayans. It was the National Renewable Energy Lab (NREL), who embarked on a 30-year campaign beginning in 1961, covering 239 locations across the U.S. and associated territories. Imagine this. How many people were even cognizant of solar power in 1961? Yet the forward-thinking scientists at NREL appreciated the value of a solid baseline dataset way back then. This level of foresight seems akin to the Mayans constructing a calendar going all the way to 2012. That’s all I’m saying. It’s a gift from the past.
I have often consulted and enjoyed the product of this work over the years—called the NREL Redbook, or more formally, the Solar Radiation Data Manual for Flat Plate and Concentrating Collectors. But with a snazzy blog post as motivation, I have taken it up a notch and produced a variety of graphical representations of the dataset to explore what it can tell us. Let’s begin the guided tour.
You may have heard about the excess carbon dioxide in the atmosphere as a result of our combustion of fossil fuels. If we wanted to sweep the excess CO2 out of the air, what would it take? How much is there? Where would we put it? In this post, we will put the numbers in perspective and briefly examine a few of the possibilities for storage.
In this post, we’ll put a physical, comprehendible scale on the amount of energy typical Americans have used in their lifetimes. No judgment: just the numbers.
The task is to estimate our personal energy volume, so that we can mentally picture cubic tanks or bins corresponding to all the oil, coal, natural gas, etc. we have used in our lives—perhaps plunked down in our backyards to bring the idea home. Go ahead and try to guess/picture how big each cube is. Continue reading →