Climate Change and Earth History

Earth has been changing its temperature over the years through a variety if natural processes. The sun’s energy, volcanic eruptions, atmospheric CO2 concentrations, and variations in snow and ice cover are among the most well-known natural climate drivers.

However, they don’t account for all of the warming that we’ve seen in recent decades. Global temperatures are rising faster than pre-industrial levels due to human activity.

1. Evolution of Life

Evolution of life on Earth has been a complex process over billions of year. It started when simple organic molecules such as amino acids were formed on the early planet.

These molecules were then susceptible to natural selection as they were made into more complex molecules. Eventually, RNA was and DNA became the main genetic molecules used today by living organisms.

However, the origins RNA/DNA are still unknown. Many theories have been offered to explain how RNA or DNA came about.

One theory is that RNA selfreplicates, or “copies,” itself to create a new molecule known as RNA polymerase. This is a critical step in the history of life, as it allowed all living things to copy their genetic information.

2. Ice Ages

Earth’s history is littered with icebergs and icesheets on land, as well as in the oceans. During these periods the Earth’s temperature was lower than it is now and winters were more prolonged than they are now.

It is still unknown what caused the ice ages. It has been difficult to identify the causes. It is possible that a combination factors such as changes in atmospheric composition and the movement of continents, as well as volcanism, played a role.

For example, evidence suggests that CO2 levels were lower at the beginning of ice age and increased as they recede. This suggests that it might have acted as a sink of greenhouse gases, though it is difficult to establish the actual cause and effect.

3. Mass Extinction Event

There have been six mass extermination events in Earth’s entire history. These are times when at most 75 percent of all species on Earth disappear within a relatively brief time.

Although rare, these extinctions have a significant impact both on the environment’s history and on Earth’s environment. These extinctions can result from comet and asteroid impact, widespread volcanism or rapid changes to geography and ocean currents.

There is much debate about what triggers these events. Some believe that the most disastrous events happen when multiple Earth systems are out-of-balance and change quickly.

This may be true in some situations, but not always. Scientists have determined that extinctions are often the result of environmental changes over long periods.

4. Climate Change

Earth has experienced many climate changes throughout its long history. Global weather patterns and temperatures can be affected by changes in the sun’s intensity and volcanic eruptions.

However, humans have played a bigger role than we thought. Carbon emissions from the burning of coal, oil, or gas have captured the Sun’s warmth in the atmosphere, warming our planet.

The human activity that has caused climate change is making it more rapid than ever. As the planet heats, the ice caps will melt and flood coastal areas, creating more severe weather.

Scientists can use indirect evidence from tree rings, corals (ice cores), sediments in lakes and oceans to study climate changes. These records are maintained in a sequence as organisms mature or sediment accumulates.