By Lighittha P.R
15 November, 2022
UPDATED 12:00 PM EST
[Photo Credit: flikr.com ]
Human civilization and agriculture first appeared during the early Holocene. Since atmospheric carbon dioxide levels stayed close to 280 ppm until the start of the industrial revolution in the 1800s, our ancestors benefitted from a very stable environment throughout this time.
Currently, carbon dioxide concentrations are close to 420 ppm, and all greenhouse gas emissions are growing quickly as a result of fossil fuel combustion, industrial activities, the destruction of tropical forests, landfills, and agriculture. Since 1900, the average global temperature has risen by just over 1°C.
Although this number appears little, the Arctic has warmed by around 2°C in this time, which is twice as quickly. Arctic (or polar) warming is the term used to describe the difference in warming between the poles and the tropics.
In comparison to Antarctica, the Arctic exhibits a significantly larger polar amplification. This distinction is made because Antarctica is a high continent covered in more persistent ice and snow, whereas the Arctic is an ocean covered in sea ice.
The weakening of west-to-east jet streams in the northern hemisphere is one of the most important consequences of Arctic amplification. Since the Arctic is warming more quickly than the tropics, there is less of an air pressure gradient, which lowers wind speeds.
It is debatable if Arctic amplification, slowing (or meandering) jet streams, blocking highs, and severe weather in the northern hemisphere's mid to high latitudes are related. According to one theory, a tight connection between recent extreme summer heat waves and winter cold waves is the primary cause of both. Recent studies, however, have called into doubt the reliability of these connections at midlatitudes.
The Arctic is warming much faster than the rest of the planet and the loss of reflective ice contributes somewhere between 30-50% of Earth’s global heating. This rapid loss of ice affects the polar jet stream, a concentrated pathway of air in the upper atmosphere which drives the weather patterns across the northern hemisphere.
Westerly winds in the southern hemisphere have recently intensified and moved further poleward, which has been related to continental droughts and wildfires, notably those in Australia. Additionally, we may anticipate stronger westerlies to have an impact on mixing in the Southern Ocean, which might decrease its ability to absorb carbon dioxide and accelerate the melting of ice shelves that surround the West Antarctic Ice Sheet due to oceanic forces.
https://arctic.review/challenges/climate%20change/?gclid=CjwKCAjwtKmaBhBMEiw AyINuwFa_Mt80d731rqVomLDtZfGfVg-rC0bDO9MGp3G2fhl7If1P3HS1exoCmQsQA vD_BwE