Burning fossil fuels.
It took 100 million years to make them & we've burned about half in 100 years.
The atmosphere has the same amount of oxygen today as it did 1000 years ago. Although oxygen gets used up in various ways, through fire and through metabolism, oxygen is constantly being released into the atmosphere by green plants.
The last time carbon dioxide (CO2) levels were as high as today was over 3 million years ago during the Pliocene epoch. At that time, global temperatures were 2-3 degrees Celsius warmer, sea levels were 15-25 meters higher, and the Arctic was ice-free.
If nitrogen and oxygen in the atmosphere were not replenished, they would last a very long time due to their stability and abundance. Nitrogen makes up about 78% of the atmosphere, while oxygen constitutes about 21%. The primary sources of oxygen, such as photosynthesis from plants, are crucial for its continuous supply; without these processes, oxygen levels would gradually decrease over centuries. However, nitrogen is inert and doesn't get consumed in significant amounts, meaning it could theoretically last indefinitely without replacements.
Over the last billion years, the Earth's atmosphere has changed significantly. Initially, it was likely composed of gases like hydrogen and helium. Over time, volcanic activity released gases like carbon dioxide, nitrogen, and water vapor, leading to the formation of the early atmosphere. The development of photosynthetic organisms like cyanobacteria contributed oxygen, eventually leading to the oxygen-rich atmosphere we have today.
Due to photosynthesising, single celled organisms, the atmosphere now has much more oxygen in it. this is possibly the most important change as with out we would exist. The atmosphere originally had much more carbon-dioxide and made the planet so hot humans would not be able to survive.
The primary reason for the increase in carbon dioxide levels in the Earth's atmosphere over the last 150 years is the burning of fossil fuels such as coal, oil, and natural gas. This releases carbon dioxide that had been locked away for millions of years into the atmosphere, leading to a rise in atmospheric CO2 levels and contributing to climate change.
The composition of gases in the atmosphere has evolved significantly over the last 4 billion years. Initially, the atmosphere was primarily composed of carbon dioxide and nitrogen. Over time, organisms like cyanobacteria produced oxygen through photosynthesis, leading to the rise of oxygen levels and the formation of an oxygen-rich atmosphere. This transition enabled the development of aerobic organisms.
In the last ten years, the population of the planet has doubled.
The percentage of carbon dioxide in the atmosphere has varied significantly over the last 4500 million years. There have been periods with much higher CO2 levels, such as during the early Earth with levels over 100 times higher than today, and periods with much lower levels, like during the last ice age around 20,000 years ago. However, the rapid increase in CO2 levels over the past century due to human activities is unprecedented in Earth's history.
World food production has doubled in the last 40 years due to advancements in agricultural technology, improved crop varieties, increased use of fertilizers and pesticides, and expansion of agricultural land. These factors have helped increase yields and meet the growing global food demand.
The increase in carbon dioxide in the atmosphere over the last 150 years has been primarily caused by human activities, such as the burning of fossil fuels (coal, oil, and natural gas), deforestation, and industrial processes. This has led to higher levels of carbon dioxide, a greenhouse gas, trapping heat in the Earth's atmosphere, contributing to global climate change.
Oxygen levels have fluctuated over geological time scales due to a combination of biological and geological processes. Factors such as changes in plant evolution, ocean chemistry, and volcanic activity have contributed to the increase of oxygen levels over the last million years. Additionally, the balance between oxygen production through photosynthesis and oxygen consumption through various chemical reactions in the atmosphere plays a role in regulating oxygen levels.
In two years
200 years ago was the start of the Industrial Revolution, when we discovered that we could burn coal in steam engines to run machines. Since then we have been burning fossil fuels (coal, oil and natural gas) all over the world in industry, transport and domestic use. This has added carbon dioxide to the atmosphere that had been hidden away for 300 million years. The carbon cycle can remove part of this, but not all, and levels have been rising slowly from around 280 parts per million (ppm) to the present levels (2018) of more than 400 ppm.
The atmosphere has the same amount of oxygen today as it did 1000 years ago. Although oxygen gets used up in various ways, through fire and through metabolism, oxygen is constantly being released into the atmosphere by green plants.
The Fourth Report of the IPCC (The United Nations' Intergovernmental Panel on Climate Change), Climate Change 2007, said:The amount of methane in the atmosphere in 2005 (1774 ppb) exceeds by far the natural range of the last 650,000 years (320 to 790 ppb).
because you're a bellend