How was the environment and climate of Earth during the dinosaur era different from today?

The climate on Earth is often variable and cyclical and so the world in the future may have a climate similar to that of the age of the dinosaurs.

Modern humans have become more interested in the state of the atmosphere, starting in post-industrial Britain, initially by monitoring particulate matter in the air, then by assessing the state of the ozone layer, and now by focusing on carbon dioxide (CO ₂ ) levels in the atmosphere, we can get an idea of ​​how the Earth's environment and climate are changing.

The truth of the matter is that the Earth's atmosphere is constantly changing. By studying the evolution of the Earth's atmosphere during the age of the dinosaurs, we can speculate on the fundamental changes that the planet's atmosphere will undergo in the future world.

Dinosaurs once ruled our planet for millions of years. But then a giant meteorite appeared and transformed them into "eternal" creatures - at least that's what science has concluded so far. (Photo: ZME).

The question we are now faced with is whether these changes are natural or man-made. In fact, modern humans would be closely related to this, and importantly, are these changes good or bad?

Most people think that a warming atmosphere spells disaster. By looking at Earth's past, we can better understand the future. What was the composition of the atmosphere like in the time of the dinosaurs? How was the air in the time of the dinosaurs different from our air today?

_{1. CO2} content

According to the National Oceanic and Atmospheric Administration (NOAA), the current level of CO2 _in the atmosphere is 417 parts per million (ppm). This is higher than in 1900 and has been steadily increasing since the Industrial Revolution. However, this number is surprisingly low compared to what scientists have found in the distant past.

Scientists calculate that carbon dioxide concentrations may have reached as high as 6,000 parts per million during the Late Triassic period (234 million years ago). This figure is consistent with estimates from other studies that suggest atmospheric carbon dioxide levels during this period were about 14 to 16 times higher than current atmospheric levels.

Scientists have known that a series of volcanic activities produced many times more CO2 _than present. (Photo: Zhihu).

Tens of millions of years ago, the reason the atmosphere was filled with carbon dioxide had nothing to do with fossil fuels or human development, but instead had to do with the state of the oceans.

During that time, the oceans were huge carbon sinks, and changes in the balance of the oceans would have prevented them from absorbing carbon. When dinosaurs roamed the continents, the oceans were unable to absorb carbon from the atmosphere.

2. Oxygen content

Oxygen levels were also much higher during the time of the dinosaurs than they are today, (at present, we have 21% oxygen in the atmosphere). Samples from 80 million years ago show that the atmosphere was 30 to 35% oxygen before the asteroid hit Earth.

Prehistoric Earth was a huge, homogeneous land mass with a thriving flora. The spacious habitat and abundant oxygen in the air are believed to have encouraged the growth of animal size. (Photo: Zhihu).

This also means that dinosaurs lived in an environment with high levels of oxygen. Interestingly, the amount of oxygen in the atmosphere fluctuates as much as the amount of carbon dioxide in the atmosphere. After the asteroid impact about 66 million years ago, the oxygen concentration in the atmosphere gradually decreased to the level it is today.

Long ago, the amount of oxygen on Earth was almost zero, and due to geological and biological processes, oxygen began to accumulate in large quantities. Oxygen is an essential component of modern life, but it also contributed to the mass extinction events during that time period.

3. Temperature

During the Cretaceous period (100-66 million years ago), temperatures were 5 to 10 degrees Celsius higher than today. Higher temperatures meant higher sea levels. In some places, sea levels were 100 meters higher than today, and in most other places, sea levels were 30 to 75 meters higher than modern sea levels. During this period, there was very little ice on Earth. Polar ice caps were also almost non-existent, except for the highest mountain peaks of the time.

According to researchers, if humanity continues to exploit fossil fuels across the planet until 2250, we could face CO2 concentrations _not seen since the Triassic period 200 million years ago. And by 2400, CO2 levels _could exceed any limit ever recorded in the geological record. (Photo: Zhihu).

4. A glimpse into our future!

The old adage says that history repeats itself. Some of the atmospheric conditions found during the Cretaceous period have led scientists to predict that Earth will become similar in the future due to climate change.

At that point, if we don't go extinct, humans will likely experience living on a hotter planet with virtually no sea ice, higher carbon dioxide levels, and more extreme weather.

Put simply, summers will be hotter, sea levels will be higher, and storms will be stronger. All of this may sound bad compared to today's climate, but our planet has been like this before.

But the biggest difference for Earth is that in the Cretaceous period , humans had not yet appeared. So the future climate could be better or worse depending on how we view the future.