The History of Climate Change

Written by:
Intro – LATOUR Noa (MOL-S4FRA)
250BC-400AD – MEKRANI Ayaan (MOL-S4ENA) & GERTSEN Emilie (MOL-S5ENA)
900-1300 – NEYENS Elodie (MOL-S4NLA)
1350-1850 – GERARD Camus-Salomé (MOL-S3FRA)
1850-20th – HOLMSTRÖM Kiara (MOL-S3ENA)
20th century – MALERBA Laura (MOL-S5ENA)

Edited by:

Climate change is the current rapid warming of the Earth’s climate which is caused by human activity and multiple other factors. It has taken nearly a century of research and data to convince most of the scientific community that human activity does alter the climate of our planet. These changes have brought a crisis which constantly affects the environment. Many people are still not convinced of the existence of climate change and it certainly doesn’t help that businesses are covering up the reality of the crisis, therefore threatening the future of our planet for their personal profit.

In the 1800’s, experiments were conducted which suggested that man-made carbon dioxide and other man-made gases damage the environment. The experiment showed that these gases would collect in the atmosphere and insulate earth. Discoveries were met with more curiosity than concern, and no one really believed that this could cause any lasting damage.

By the late 1950’s, the data of CO2 emissions offered some of the first data on climate change and how green-house gas emissions were damaging to the environment. This data also proved that not only was climate change real; it also presented several dire consequences for the planet. Now, to understand climate change further, we have to first understand the history of it.

250BC-400AD, The Roman Warm Period

The period 250 BC to 400 AD is known as the ‘Roman Warm Period’. The Roman Warm Period was a period of unexpected and unusual warm weather in Europe, as well as in the north Atlantic.

Theophrastus, a Greek botanist, did extensive research on how the climate and quality of soil affected trees, which is how we know so much about the Roman Warm Period. Botany is the study of different aspects of plant life including plant structure, genetics, physiology, ecology, classification, distribution, and the economic importance of plants. This study is done in a particular region, and it can tell us about what drastic climates those plants have gone through.

Studies that have been done show that the Mediterranean climate was on average 2C° warmer than what we see today. They also show that the temperatures of the south Aegean in the 4th and 5th century are within a degree of the temperatures that we experience today. This tells us that the climate is constantly changing.

Some scientists think that after the Roman Warm Period came a long period of cooling that lasted up until the industrial revolution. The industrial revolution was also a time when humans started producing CO2 emissions. These emissions were so high that scientists at the time started to notice a change in the climate. With this in mind, it is most likely that the Roman Warm Period was caused by natural climate change. Just as ice ages occur, so do warm periods, and that was most likely the cause of this period of unusual warm weather.

That being said, the climate change that we are experiencing today is not the same as that of the Roman Warm Period. Although temperatures have not changed much since, what we are currently undergoing is not simply a natural weather change. The results of human activity are leading us to a worse Roman Warm period with devastating environmental disasters.

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900-1300, The Medieval Warm Period

Just a few centuries after the Roman Warm Period, you will find a period called: ‘The Medieval Warm Period’. The date of this period can vary because many scientists argue about the specifics of this period. Most people believed it lasted from 900 AD to 1300 AD.

The Medieval Warm Period was a period of unusually warm climate in the North-Atlantic region. Although in some other regions, it felt more like a period of unusually cold climate, such as the tropical Pacific. There have been a lot of scientists who have studied climates searching for biological causes for the Medieval Warm Period. Some biological causes include the change of ocean circulation, increased solar activity and reduced volcanic activity.

It is said that since the Roman Warm Period, the Medieval Warm Period was the warmest period in the northern hemisphere. There has been lots of research done in many countries regarding the effects of the Medieval Warm Period. One of the most prominent scientists was Hubert Lamb (1965). He was a ‘paleo climatologist’; which means he studied the different climates throughout the Earth’s history. To do his studies, he used a technique called: ‘botany’.

With the results of that experiment, he concluded that the Medieval Warm Period was a period that had lots of unusual temperatures. Hubert Lamb believed the period to be around 1000-1200AD. He concluded that it was followed by a colder period known as: ‘The Little Ice Age’. He also talked about ‘global cooling’ and ‘global warming’. He warned that it could have serious effects to our lives within the century. He was later proven to be correct with his predictions.

Before Hubert Lambs, there were not many scientists who thought the change in the earth’s temperature had something to do with climate change. Around 900-1300, scientists did not consider there to be such a thing as ‘climate change’. People first started talking about ‘climate change’ in the early 19th century, which is also the time Hubert Lamb started publishing his theories.

There are also some historical events linked to The Medieval Warm Period. Some scientists think it is linked to the fact that the climate back then was warm enough for the Vikings to journey all the way to Newfoundland. The diet of the Vikings was composed of around a quarter seafood which was possible back then. This is because it was warm enough to be able to catch seafood. When it got colder, they started catching seals, which thus became a huge part of their diet and subsequently their culture.

In the 20th century, the temperature of the Earth is higher than that of the Medieval Warm Period. As Hubert Lamb concluded, The Medieval Warm Period is intertwined together with The Little Ice Age. This ‘Little Ice Age’ is also the cause of the colder temperatures which made the Vikings eat more meat. We can conclude that, as mentioned before, today’s temperatures are warmer than the ones in the Medieval Warm Period.

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1350-1850, The Little Ice Age

The Little ice age was a period of cooling that occurred from 1350 to 1850. Although this period was no true ice age, we still refer to it as ‘the Little Ice Age’. It was modestly colder than the periods before it. The Little Ice Age brought colder winters to parts of Europe and North America. Farms and villages in the Swiss Alps were destroyed by encroaching glaciers. Crop practices throughout Europe had to be altered to adapt to the shortened, less reliable growing season, and there were many years of death and famine.

Scientists have tentatively identified possible causes of the Little Ice Age: decreased solar activity; increased volcanic activity; altered ocean current flows; fluctuations in the human population in different parts of the world causing reforestation or deforestation, and the inherent variability of global climate.

1850-20th, The Retreat of the Ice Caps

Starting from 1850, two crucial things occurred concerning climate change. Firstly, the glaciers started retreating. And secondly, there was a temperature increase of 0.25°C. Glaciers in central Europe started to grow during the ‘little ice age’. That happened between 1550 and 1850. After 1850, the glaciers started to generally retreat, as shown in further detail in the Belgian Earth Observation. Glaciers are important indicators of climate change. The melting ice sheets add to the rising sea levels that are threatening many big cities at the coast and many islands. They can affect the supply of fresh water for lands, crops, people and animals.

This proves that we could see the consequences of global warming as early as 1850. In 1890, Svante Arrhenius and P.C Chamberlain found out that CO2 was building up in the atmosphere and that it may start causing problems. Both scientists realized that the burning of fossil fuels could lead to global warming. Sadly, almost nothing was ever done about it.

20th Century, The Current Climate Change Crisis

The 20th century was an era packed with scientific discoveries regarding climate change, and the action- or some could say inaction- we took with our newfound knowledge is another theme that’s pertinent to this revolutionary period. If you’ve ever wondered where the facts of global warming stem from, who the scientists involved were, and why people seem to be so ignorant of this climate crisis, keep on reading…

Little was known about global warming at the beginning of the 20th century, but as time progressed, physicists and engineers like Knut Angstrom, Andrew Ellicott Douglass, Guy Callendar and Gilbert Plass all started to catch on with the fact that, indeed, carbon dioxide concentrations in the atmosphere were increasing, and so was the global temperature. Scientists prior believed that this excess CO2 would simply be absorbed by the ocean, but oceanographer Roger Revelle and chemist Hans Suess proved this theory wrong. In order to measure the increasing levels of CO2, Charles David Keeling began systematic measurements in Hawaii and Antarctica, which still continue to this day. His measurements provided the first, unequivocal proof that CO2 concentrations were in fact rising. (In the 1950’s, 5 billion tonnes of CO2 were emitted each year, and we are now at 36 billion tonnes per year: for context).

Alas, by the 1950’s, the evidence for global warming slowly began to rack up and turn into a substantial, quite serious, issue.

In the 1960’s, global warming started to gain public and political attention, as the US advisory committee panel warned that the greenhouse effect was a matter ‘of real concern’. Multiple organisations like The United Nations Environment Program (UNEP) or the more widely known Intergovernmental Panel on Climate Change (IPCC) started to form; their goal: to collect all relevant data, find solutions to the crisis and finally tackle global warming once and for all.

The IPCC continue to release reports that clearly indicated global warming’s disastrous effects on our planet. Events like the Earth Summit in Rio de Janeiro took place in 1992 (to discuss the crisis and its implications) and treaties like the Kyoto Protocol formed, pledging nations on an international level to reduce emissions. However, in the end, not very much was being done to combat the rapidly growing environmental emergency. In fact, the US senate immediately declared that it would not ratify the Kyoto Protocol, and President George W. Bush decidedly removed the U.S from the Kyoto process in 2001. Why were nations suddenly reluctant to combat global warming?

To understand this, we need to go back to the 1950’s.

You must realise that the scientists mentioned earlier (Callendar, Revelle, Keeling) weren’t the only ones who started to notice the new, peculiar climatic changes. Exxon Mobil, the American multinational oil and gas corporation, had their eyes on the situation, as well.

Their environmental researchers found that not only were CO2 levels rising because of the burning of fossil fuels, but they also figured out what the exact effects of this would be. Elmer Robinson warned, ‘significant rises in CO2 could melt ice caps, increase sea levels, change fish distributions and increase plant photosynthesis’.

To make matters even worse, a document from one of Exxon’s meetings (held with multiple other oil and gas corporations like Shell and Texaco) suggested that they knew they would bear some responsibility in managing global warming. On top of that, M.B Glaser (Exxon’s environmental affairs program manager) sent their management a warning that was restricted to Exxon personnel saying, ‘potentially catastrophic events could occur if fossil fuel use is not reduced’.

If word got out about their findings on global warming, Exxon realised that this would mean bad news for their business. So, what did they do? They got together with other fossil fuel companies and created the Global Climate Coalition (GCC) to try and obscure the scientific understandings of climate change, and essentially, deny it even existed. Furthermore, they funded various climate denial organisations, lobbied for politicians to keep quiet about the crisis and opposed regulations to curtail global warming.

The good news is that organisations like Brussels-based Watchdog; Corporate Europe Observatory, the Royal Society and Attorney Generals from multiple U.S States started to grow suspicious of ExxonMobil’s covert activities. However, each time Exxon Mobil underwent investigations that exposed the company for spreading ‘Fake News’ about climate change, Exxon simply denied any wrongdoings. It took until 2019, when Exxon sued the Massachusetts Attorney General (Maura Healey), that the Supreme Court was found in favour of the Massachusetts Attorney; meaning that Exxon could no longer withhold investigations into whether or not the company knowingly misled the public for their own benefit.

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As a result, the awareness and scientific knowledge of climate change is slowly becoming more widespread. The History shows us that our temperatures have only become warmer, and that we have to find a way to lower the earths temperatures before climate change becomes an even more serious problem and has prolonged negative effects. Sadly, there’s still a long way to go- and the question is, will we have time to do something about the climate crisis by the time we’ve even just accepted it?







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