Today is Monday, 28 August 2024.
The title of today's article is a phrase by Howard Lee, geologist and award-winning scientific writer.
With it we begin a week of scientific articles, today being the first part of one that deals with climate change on a geological scale.
Geological scale means a time scale that is much longer than the 100 years that some of us human beings eventually live.
The Earth has existed for about 4.5 billion years and has faced other cycles of heat and cold. “Only” in the last 500 million years there have been some extremely warm eras, without ice and with high ocean levels, and other very cold eras.
This is what a project from the Smithsonian Institution indicates, as mentioned in a great article on the Climate.gov Science & Information for a Smart Nation portal from the National Oceanic and Atmospheric Administration (NOAA) of the United States and source of the image below. By clicking on it you access the article "What's the hottest Earth's ever been?".
The science that studies climate variations throughout Earth's history is called paleoclimatology.
The most used techniques focus on the natural remains around us, such as rocks and sediments, fossils and petrified trees, glaciers, the air bubbles they contain and corals. In a more sophisticated way, there is also so-called radiometric dating, which analyzes the evolution of the molecular (de)composition of elements. In other words, knowledge of chemistry is essential.
According to Howard Lee, volcanoes, metamorphic rocks and the oxidation of carbon in eroded sediments emit CO2 into the atmosphere, while chemical reactions with silicate minerals remove CO2 and capture it in the form of rock, especially limestone, which is the main raw material for cement. The balance between these processes works like a thermostat.
This “weathering thermostat” takes hundreds of thousands of years to react to changes in atmospheric CO2. Earth's oceans may act a “little faster” to absorb and remove excess carbon, but even that takes millennia and can be overloaded, leading to ocean acidification.
Currently, the burning of fossil fuels emits about 100 times more CO2 than volcanoes - too fast a rate, geologically speaking, for the oceans and weather to neutralize it as always happened until the Industrial Revolution. This is why our climate is warming and our oceans are acidifying.
Complex?
This would be just 1 out of 10 situations that Howard Lee indicates as related to climate change in the Earth's geological past.
Click here to Howard Lee's own website, a portal full of other great references for anyone interested in the topic.
We conclude with a quote indicated on ou portal, from a scientist contemporary of the Industrial Revolution and father of modern chemistry, Antoine Lavoisier, :
“In nature nothing is created, nothing is lost, everything changes. We must trust to nothing but facts: These are presented to us by Nature, and cannot deceive”.
Don't miss tomorrow’s the second and final part of the article, with the other situations.
