The carboniferous period was a time of tremendous growth on Earth. One of the reasons for this was the average worldwide temperatures. Naturally, there wasn’t anyone around with a thermometer to get accurate readings of the amount of heat. However, temperatures can be extrapolated, using different methods, with the right kind of understanding.
Shallow seas
Rock cores collected during this time period show that much of the land was covered with shallow, swampy seas. These would have warmed up readily, and since water is an efficient medium to transfer heat, the warm water would have ensured that most of the planet would have been hot and humid. At the time, there weren’t even polar ice caps. The air temperatures were too high.
Land mass
During the carboniferous, the land wasn’t spread around as it is today. Instead, it was clumped together. This means that there was nothing to prevent ocean currents from flowing from one pole to the other. Sediments were laid down by the currents and over millions of years, these became compacted, which gives scientists clues regarding the climate by using core samples.
Indicator species
Certain plants and animals will only live at the correct temperature. These were captured in the sediments, giving an indication of the temperature of the ocean in a given location. The indicator species show that the earth was uniformly warm. It would have been far different than it is today, with temperate areas and places where it becomes frigid and stays that way through much of the year.
Plant life
The explosion of plant life is one thing the carboniferous is known for. It is important enough that the name of the period alludes to this. It was during this time period than millions of tons of plant matter were laid down in a way and in quantities that prevented much of it from breaking down and rotting. Eventually, the vegetation was covered by sediments, which became compacted. After a great deal of time, the material became converted into coal and oil, hence, the name: Carboniferous time period. This is over simplification of a complex process, however it is unlikely that it could have happened if the temperatures weren’t fairly high.
Differing opinions
Because the climate can only be measured second-hand, through rock samples and similar methods, there is some disagreement about just how hot it was. There is little doubt that it was warmer than it is today but it is difficult to get precise in regard to how much warmer. It should also be noted that when it comes to global temperatures, a relatively small fluctuation can have a huge impact. If the average temperatures on the planet were to increase by just five degrees F., the result would be catastrophic. A drop of the same amount could be enough to trigger another ice age.
This last part is important to understand when it comes to discussing how hot the earth was during the carboniferous. It is safe to say that the average global temperatures were at least several degrees hotter than they are now. That may not sound like a lot, however, considering that the temperatures were much more uniform than they are now, it is easy to picture the entire planet as a giant, steamy swamp.
This isn’t entirely accurate, as there would have been areas where the ocean was deep. Still, the steamy swamp idea isn’t a bad way of thinking of it. The average global temperatures would have been at least several degrees warmer than they are now, and could have been over 10 degrees warmer. Some scientists suggest that the temperatures may have been much hotter.
