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During the 100,000 years of existence of our species on Earth, global climate change has been cyclical.
Have you noticed that time is almost never average?
So, of course, the average time means something different each day. So, how is it that global climate change is something special? In fact, climate change is the norm, in the short and long term. During the 100,000 years of existence of our species on Earth, climate change has been cyclical.
Currently, we are coming out of an ice age. This does not mean that the climate has been continually warming slowly. Climatic cycles can turn in a year or persist for centuries. But it's a question of perspective. The longer the period considered, the less apparent are the short-term climate changes.
Climate change has been happening on Earth for millions of years. If we looked at a map of climate change over those millions of years, it would seem that the climate has not changed much. However, if we consider the changes in life on Earth caused by climate change, these seemingly small changes become extremely important. Even more if we simply look at the age of 100,000 years.
Currently, we observe an upward trend in global average temperatures that began when the Little Ice Age ended in the 17th century after the founding of Jamestown, Virginia. The Little Ice Age coincided with a period of increased volcanic activity.
Previously, it was the warm medieval period that lasted from about AD 900 to 1350. This was the schedule of exploration from Viking to North America. The less polar ice at that time made it possible to navigate in waters further north.
The age of darkness is between 550 and 900 AD, during another cold period coinciding with increased volcanic activity. He followed a warm cycle from the birth of Christ until 550 AD. It was the time of the maximum power of the Roman Empire.
The Greek Empire was produced during a cold cycle that lasted from about 550 BC. until the birth of Christ.
A very hot period lasted about 1500 B.C. at 550 B.C. The exodus occurred at the height of this hot cycle, around 1100 BC. It does not even bring us back to the ice age. However, it is long enough to clearly demonstrate the cyclical nature of global climate trends.
Also, to demonstrate that a global warming climate is not unusual, the Earth's climate as a whole has been high and has fallen several times in response to various stimuli.
These are the stimuli that worry most of our leading scientists.
Among the causes of past climatic cycles include solar activity, the structure of the ocean surface temperature, growth or lack of vegetation, the evolution of the sun, plate tectonics, the natural production of carbon dioxide. A single volcanic eruption fills the atmosphere with dust that blocks the light and lowers the temperature. Mount Tambora experienced a huge eruption in 1815, the largest eruption in recorded history, which caused "the year without summer" in 1816 when it snowed every month in North America and Europe.
Climate change occurs for reasons. The Earth's oceans have been warming for at least 50 years, probably due to a series of hot El Nino effects.
Since the industrial revolution, the human use of fossil fuels has resulted in massive pollution in the atmosphere. Other less obvious activities add even more pollution to the atmosphere. Deforestation in large areas has disrupted the oxygen balance. Human development has replaced forests and grasslands with large areas of cement and bitumen that increase temperatures.
There is no absolute proof that pollution caused by human activities is causing global warming. This would explain a significant drop in temperatures in the north of the United States, Europe and Asia in early 2017, which did not prevent this year from being the third hottest ever recorded.
The hottest year was 2016 and the five hottest years have been since 2010.
The cyclical nature of the Earth's climate has been used as an argument against measures to prevent the reduction of pollution. What looks like playing cards on the tracks when you can hear a train going around in the bend.
Mike Bleech can be contacted by email at [email protected]. Read more of his columns on nwpaoutdoors.com.
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