This week, we have a look at a chart of one of our users again. It was created by Joshua Byrd, a data journalist and software developer at ABC News in Brisbane, Australia. He’s part of the ABC News Story Lab, a team that creates one chart a day.
He emailed Elana (who wrote last week’s Weekly Chart; thanks, Elana!) asking if we could extend our limit on the number of rows in bar charts. Until that point we had allowed 500 rows. He wanted more. His goal: to show the insignificance of humans. So we gave him more. Have a look at his chart in its natural habitat on abc.net.au or here:
We can see that planet Earth is full of viruses, bacteria, plants, fungi, crabs, lobsters, snails, squids, jellyfish, worms, insects & fish. And almost no humans. The human race is a lightweight on this planet.
Note that the chart only shows the carbon mass, not the total mass. If we assume an average weight of 50kg per human, the 7.6 billion people on this planet weight 0.38 gigatonnes together. But we’re made out of 70% water. And only half of the remaining 30% is carbon. That’s 8kg carbon per person; or 0.06 gigatonnes for the whole of humanity.
I imagine Joshua looking at the numbers for this chart and thinking: “Damn.” They are on vastly different magnitudes, ranging from 0.007 gigatonnes (wild mammals) to 450 gigatonnes (plants). A bar chart only works if numbers have a similar magnitude. If the numbers are too different, tiny numbers become invisible. We can see that here, where I put some of Joshua’s data points in a normal bar chart:
The chart doesn’t let us compare the smallest numbers (0.7, 0.06 & 0.007). So Joshua thought beyond the normal bar chart. Here’s what he says:
“It became clear that the numbers we were talking about were not really going to come across in a standard bar chart so I had the idea of seeing if I could break the bars over multiple lines.”
Genius. In his chart, tiny numbers become visually comparable, while big numbers put them in the right perspective. And scrolling down without an end in sight gives us an almost tactile sense of the weight of plants and bacteria. (Try to achieve that with a normal bar chart.)
We’re a big fan of Joshua’s approach – and his other charts at ABC News. Visit the one that shows the months in which most children are born in Australia, or this fun chart about bee exports. I’ll see you next week!