Guest Opinion: Dr. Tim Ball
In a recent article, I used an illustration of 1200 km circles around a weather station to illustrate the extent the IPCC considered it represented. A comment about the article asked if I was aware of the map distortion and its effect on the circle of coverage. It was an arcane but important observation. He was pointing to the distortion created by using a Mercator projection map.
I am very aware of the distortion. My entire career involved working with maps. This included flying in the Air Force; teaching courses and running labs about maps and map reading; studying climate weather maps; the movement and migration of people driven by climate change; and teaching a course in political geography. I provided major research for a book on the search for the Northwest Passage on the Pacific west coast written by Sam Bawlf titled, “The Secret Voyages of Sir Francis Drake.” Dr. John Dee, science advisor to Queen Elizabeth I, gave Drake his sailing and scientific instructions. This included accurately determining the longitude of the west coast of North America. This research resulted in Drake visiting the Dutch map maker Abraham Ortelius (1527-1598) after his return. Two months after Drake’s visit Ortelius produced a new world map with the coast shifted 60° of longitude to its proper position.
Dee drew a map for Elizabeth I that illustrates his spatial awareness of the world (Figure 1). It is a unique perspective, even for today’s space-age citizen because it is looking down on the North Pole. Our view of the world and spatial relationships were distorted by the Mercator map introduced in 1569. Its specific purpose was to make navigating a three-dimensional world using a two-dimensional map easier.
The distortion of a Mercator map increases as you move away from the Equator until the North and South Poles, single points on the Earth, become as long, 40,075 km, as the Equator (Figure 2). The problem is it became the standard projection in the classroom and society. In many ways, it set back understanding of the spatial form and relationships on the Earth and in our solar system. This seriously hampered the understanding of geographic relationships, climate, and climate change.
Historians talk about the Greek Miracle, a period from 700 to 400 BC. The global climate of the period, which began cooling around 850 BC, was cooler than today. Greece was cooler and wetter and conducive to plant growth similar to France today. Central to the Greek Miracle was the understanding of the third dimension. It is manifest in the construction of the Parthenon. They built the center of the base higher than the ends to offset the distortions caused by the eye to make it appear level. The columns bowed out in the middle to prevent them from looking bent in when viewed from below.
Awareness of space and the third dimension allowed them to calculate the Earth’s circumference accurately. Eratosthenes did it by measuring the difference in the length of the shadow of a stick at noon at two locations (Figure 3).
The idea of a differing angle of the sun is critical to understanding climate and climate change. This is why the word climate derives from the Greek word for inclination. It is also why the Greeks were able to identify three climate zones, the Torrid, Temperate, and Frigid, (Figure 4).
The three-dimensional (3-D) understanding disappeared during what some historians call the Dark Ages. Regardless of the semantics about the phrase, it was a period when the Catholic church dictated the western view of the world. They supported the Ptolemaic view of a geocentric universe, that is with the planets, including the Sun, orbiting the earth at the center.
This view held until Copernicus (1473-1543) proposed the heliocentric, Sun-centred system, in 1514. In fact, his theory did not receive public disclosure until after his death in 1543. He knew the dangers associated with opposing prevailing wisdom. The other problem is all the visual and other evidence for the public contradicts the theory. Physical evidence to prove the theory didn’t appear for 182 years. It occurred in 1725 with the discovery of parallax. Few know or understand it, but then it is of no consequence to most people’s lives. A survey shows that 1 in 4 Americans believe the Sun orbits the earth.
The Copernican Revolution marked a return of the 3-D perception of the world. It also marked the return of the Greek perception in all aspects of western society, known as the Renaissance, or rebirth. (Some wag in England dubbed it the ‘Wrenaissance’ after Christopher Wren who reintroduced classic Greek architecture to England). Music introduced the concept of harmony. Art rediscovered the vanishing point exemplified in the works of Canaletto (Figure 5).
Most people live in the world they perceive. For example, the Inuit tradition is the Earth is saucer-shaped because there is a mirage effect in the arctic called looming. A thin layer of warm air close to the surface that makes the horizon ‘rise up’ creates it. The visual evidence for most people is that the Earth is flat with a surrounding rim.
There are few places where you can be high enough with a flat surrounding to see the Earth’s curvature. That doesn’t mean they don’t know the Earth is round, it is simply their experience. It also means they rarely think about things in a 3-D way, which brings us back to the Mercator projection and its influence on spatial perceptions of the Earth.
Benjamin Franklin (1706 –1790) was one of the most perceptive and aware people in history. He was, by all measures, a legitimate polymath. However, he also spanned the onset of the Renaissance. As the first joint postmaster general for the American colonies he increased the speed of mail between America and France. This was especially important during the US Revolution. He provided thermometers to postal ships, so they could stay in the warm, strong North Atlantic Drift going east and avoid it going west.
Despite this, and his experiments with kites and lightning, Franklin could not understand the wind patterns associated with mid-latitude cyclones. This was a spinning motion around a low-pressure center that moved across the country. It wasn’t until 1857 that Dutch meteorologist Buys Ballot established the relationship between wind direction and the horizontal pressure pattern. As part of my instructions for Canadian farmers on how to track weather systems, I taught the simple method based on Buys Ballot’s Law for tracking the movement for the center of a low-pressure system. In the Northern hemisphere with the wind at your back, the low is on your left. They combine with this with a barometer to determine the direction and movement of the system. They can calculate when it will pass and allow them to plan to get chores done.
The public lack of 3-D perception continues. Most are unable to imagine or even explain how the moon orbits the Earth. People look at weather maps but are unable to visualize the 3-D atmosphere. Few know the Troposphere that effectively marks the top of the atmosphere in which weather occurs is twice as high over the Equator with an extreme difference between 20 km at the equator in summer and 7 km over the Poles in winter. For most people, the weather is 1-D, while climate is 3-D. The Milankovitch Effect illustrates the challenge to understanding climate change (Figure 6).
Most people understand that the Tilt of the Earth is a constant 23.5°. They understand the Orbit is unchanging and slightly elliptical. They have more difficulty imagining the orbital change, even when they learn it is due mostly to the changing gravitational pull from Jupiter. The Tilt is more difficult to grasp because they don’t know how slow the Earth rotates relative to its size, and there is no established cause for the change. They really get lost when trying to understand the Precession of the Equinox, which is a combination of different effects. All this lack of knowledge is about information known to science starting 176 years ago.
Another complicated 3-D concept for 2-D people to grasp is Coriolis Force. The name is incorrect because there is no force. It is properly the Coriolis Effect that in reality appears to create a force affecting anything moving across the surface of the Earth. I illustrated the difficulty of imagining and intellectualizing the process by telling the students that if you look down on the North Pole, the Earth is spinning counterclockwise, but it is a clockwise spin when looking down on the South Pole. I then took a globe pointing the North Pole toward them, and while spinning it in the same direction, slowly turned the South pole toward them. Some thought it was a trick globe, others asked for a repeat of the demonstration, most looked very puzzled.
The challenge in climate is somewhat similar to map making. That is, to take a globe (3-D) and display it on a flat surface (2-D). If you only want to focus on one issue like Great Circle routes (the shortest distance between two points) as with the Mercator projection, you can effectively ignore all other factors. Science calls this ceteris paribus.
It was what early claims of anthropogenic global warming did. They said if we raise the level of CO2 in the atmosphere temperature will increase, with the critical limitation of ceteris paribus. It is far from that in a complex spherical world that is rotating. Unfortunately, for those trying to explain climate and climate change, none of this is of any consequence to most people. They are quite happy in their 2-D world. The 3-D world of climate only became an intrusion into their 2-D people world when it was exploited by a few for a political agenda.