On Climate Change
Updated: Dec 31, 2019
One of the side effects of climate change: More frequent and more violent storms.
In 1088 the Chinese scholar, engineer and philosopher Shen Kuo was the first who suggested that climate is not constant but undergoes periodical and sometimes radical changes. He came to this conclusion after he found petrified bamboo roots and trunks that had been revealed after a landslide at a riverbank. As there was no bamboo growing in the area when Shen Kuo made this discovery, his logical deduction was that sometime in the past the climate in this area must have been different for allowing bamboo to grow.
For most of Earth’s history these changes in climate were triggered by natural events like the Earth’s orbit around the sun, volcanic eruptions, the movement of tectonic plates and the subsequent rearrangement of land masses, the flow of oceans currents and probably some other factors we don’t know about yet.
In the early 20th century Milutin Milankovitch, a Serbian engineer and mathematician, laid out the theory of how three variations of Earth’s orbit around the sun could influence the climate. In a cycle that takes around 100.00 years the Earth’s orbit around the sun changes from elliptical to nearly circular which changes Earth’s distance from the sun and subsequently the amount of solar energy that reaches Earth. Another cycle that lasts about 40.000 years causes the tilt of the Earth’s axis to vary between 22.1 and 24.5 degree which influences the distance of the poles to the sun which again causes a change in the severity of the seasons. More tilt means more severe seasons - cold winters and hot summers - less tilt means mild winters and cool summers. It is the latter scenario that is (or was… ) responsible for the ice ages. The cool summers allow snow and ice in high latitudes to survive throughout the summer months which causes a feedback effect. Snow covered ground reflects more of the sun’s energy back into space which causes additional cooling and allows ice sheets to extend further south away from the poles. The third variation is the change in axial precession which influences the seasonal contrast in the two hemispheres.
On Earth itself a major factor in the stability or instability of the climate is the concentration of carbon dioxide in the atmosphere. This connection between climate and carbon dioxide was discovered by Svante Arrhenius, a Swedish chemist, who published his treatise On the Influence of carbonic Acid in the Air upon the temperature of the ground in 1896. Only a few years later, in 1908, Svante Arrhenius was also the first who made the connection between the burning of fossil fuels and the resulting rise in atmospheric carbon dioxide and global temperatures. He however saw this as a positive and predicted that a warmer Earth would produce more and better crops and allow humanity an easier life. What Svante didn’t know about were all the other side effects rising global temperatures would bring.
In the past high greenhouse gas concentrations have been mainly caused by massive volcanic events. These events not only released greenhouse gases as part of the actual eruptions, the disturbances in the Earth’s crust opened up fossil fuel deposits and the hot magma set these deposits on fire releasing even more greenhouse gases. The release of carbon dioxide, methane and other greenhouse gases into the atmosphere then caused a rise in the average global temperature and the Earth warmed up. Between these volcanic events the orbital cycles and the other beforementioned factors allowed the Earth to cool down again.
Ireland is an extreme example of deforestation. It has the lowest forest cover of all European countries, today only around 10% of the country are covered with trees.
After the end of the last glaciation the northern hemisphere experienced a time of settled climate, not too hot and not too cold. Scientific evidence, based on what was discovered in ice and mud core samples, suggests however that we were heading for another cold period with glaciers ready to extend once again over Europe. But before this could happen another factor had come into play. Homo Sapiens had left its cradle in Africa and Mesopotamia, an area that today roughly corresponds to Iraq and parts of the surrounding countries, and by the time the glaciers of the latest cold period had retreated to the polar regions humans had already occupied every continent except Antarctica. It was probably then when men-made climate change began. Populations rose, agriculture spread, people burned or chopped down forests to clear space for their crops and gain building material. In Roman times half of all European forests were already gone and in China people had started burning coal instead of wood to heat their homes. At this time the men-made greenhouse gases and the burning and cutting down of the natural carbon traps, the world’s forests, were just enough to prevent another glaciation and secure food production and further evolvement of the human race.
The rest, as the saying goes, is history. The Industrial Revolution came with large scale burning of fossil fuels - coal, oil and gas - while more and more forests disappeared to make way for ever bigger farms to feed the exponentially growing human race. When exactly we crossed the tipping point nobody knows for sure but we are now caught up in an event we still can’t fully comprehend. Our carbon dioxide emissions are raising the average global temperature. The subsequent disappearance of glaciers and sea ice in both the northern and southern hemisphere allow more energy from the sun to reach the Earth’s surface instead of being reflected back into space by the white ice sheets which causes further warming. At the same time areas that had been locked in permafrost for millennia are starting to thaw, allowing the ground to release its stored greenhouse gases which again accelerates the rise in temperatures.
A changing climate always affects life on Earth and the more extreme the event the more devastating the effects. Most of the climate change events we know of were followed by a mass extinction. The biggest of these mass extinctions, known as The Great Dying, was the Permian (or Permian – Triassic) Extinction some 250 million years ago and almost rid Earth of all complex life. This event started after the area of today’s China experienced a series of volcanic eruptions and nearby Siberia hemorrhaged lava for millennia. This initially caused a volcanic winter which was followed, after the ash clouds had cleared, by a rise in global temperatures by 10 degrees. The result was a lethally hot tropical zone and an extreme acidification and oxygen depletion of the oceans that caused even seabed burrowing worms to disappear.
A similar series of events caused the demise of the dinosaurs. Massive carbon dioxide emissions caused by volcanic eruptions in India pushed global temperatures upwards by almost 8 degree. The infamous asteroid most likely didn’t have any direct impact on the dinosaurs and other life but it is thought that its crash provoked further volcanic activity which eventually meant a drastic change in climate and the end of the dinosaurs.
The replacement of species rich meadows with fast growing grasses is one of the reasons why insects are disappearing.
We are witnessing a similar event in progress. The big difference however is that we are actively and knowingly causing the climate to change by saturating the atmosphere with carbon dioxide and other greenhouse gases while still clear cutting one of the few entities that are able to remove carbon from the atmosphere. Thanks to the Keeling Curve we have known for a few decades that there is a direct link between us burning fossil fuels and the rise of atmospheric carbon dioxide. The effect of carbon dioxide on global temperatures has been known for even longer and we are also aware of the effect carbon dioxide has on the world's oceans. At the same time we are polluting and destroying habitats belonging to plants and animals and so pushing many species to an even quicker extinction. But just like an ancient volcano it doesn’t seem possible to stop this current event.
The underlying problem of all of this is obviously us, our sheer number (we went from 1 billion in 1800 to currently almost 8 billion) and our ignorance and disconnection to the natural world. Chief Seattle once said:
Humankind has not woven the web of life. We are but one thread within it. Whatever we do to the web, we do to ourselves. All things are bound together. All things connect.
As long as we see ourselves as the crowning achievement of evolution, as long as we see ourselves being better than all the other life forms on this planet and as long as we put economic growth and the accumulation of wealth above everything else, I doubt there will be any significant changes or to use another Native American quote:
Only when the last tree has died and the last river has been poisoned and the last fish been caught will we realize we cannot eat money.
Sign of the times: Fulmar using a bottle as nesting material.
You could of course argue that none of what is happening right now will matter in the long run. In the big picture we will just be another volcanic event followed by a mass extinction, Earth will recover, new species will evolve and life will go on. The difference with us however is that we consider ourselves intelligent which gives us a responsibility for the planet and its inhabitants. So far we have been behaving like an infant alone in the sweets section of a supermarket, take what we can, no matter the consequences. It is like Uncle Ben said: With great power comes great responsibility (for those not familiar with the Marvel superheroes, Ben is Spiderman's uncle). We have the power but very much lack responsibility, so we will have to change, we will have to change the way we think, the way we live our lives and the way we interact with the planet we are living on.
Carsten Krieger, December 2019