THE SCIENCE BEHIND SUSTAINABILITY
Climate Change is the result of years of human activity polluting the oceans, Earth, and the atmosphere. These polluters mainly come from burning fossil fuels for energy, which releases greenhouse gases (GHGs). Other research has shown that chlorofluorocarbons (CFCs) - which are released during refrigeration processes - have played a major role in global warming; in some cases, the temperature fluctuation trends match up better with CFCs than CO2 - the most concentrated GHG. Another component of climate change has been the ozone layer which is responsible for protecting the Earth from the Sun’s ultraviolet rays. Since the industrial revolution, CFCs, along with other human-produced chemicals, have played a primary role in ozone depletion. These all contribute to global warming and additionally create a blanket effect over the Earth’s atmosphere.
GREENHOUSE GASES
The natural balance of the Sun’s energy and heat entering the atmosphere and reflecting back into space has been altered because of GHGs. Currently, there is detrimentally less energy being re-emitted. Instead, the energy is getting trapped in the atmosphere. When the radiation from the sun reflects back into space, GHGs absorb some of the energy. The GHG molecule then vibrates because of increased energy, and the radiation is released back in any direction. This disturbance in the balance of energy entering and exiting the atmosphere becomes an issue because of the years of mass-produced GHGs causing a buildup. This causes global temperatures to increase; Additionally, the ocean expands when temperatures warm, and the ocean consumes 90% of the Earth’s heat. Furthermore, global temperatures have increased faster over the Northern Hemisphere than the Southern Hemisphere, as well as over land than over oceans.
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The most prominent GHGs include carbon dioxide, water vapor, methane, and nitrous oxide;
others include sulfur, hydrofluorocarbons, perfluorocarbons, and CFCs.
Certain GHGs are more potent because they obtain and release a higher level of energy per round emitted.
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From 1970 to 2000, there was an increase in GHGs of roughly 1.3% each year; then from 2000 to 2010, the increase rose to 2.2% per year. As of 2015, CO2 counted for 82% of GHG emissions. In the 1850s there was an average total concentration of 280 ppm, which rose to 403 ppm in 2016 -- today the number is closer to 450 ppm. The last time there was a recorded level of concentration above 400 ppm was 3-5 million years ago, and at that point, sea levels were 20 meters higher than they were in 2018.
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There is evidence of massive increases in sea level across the world, with a predicted 1-foot to 4-foot rise in sea level by 2100. One explanation is that due to the increased temperatures, Arctic sea ice is melting 11 days earlier and refreezing 26 days later than expected compared to data from the 1970s. In October of 2017, the volume of Arctic sea ice was 65% below the maximum level. The recovery process of the ozone layer has even substantially slowed with the colder temperatures produced by GHGs trapping heat just below the surface of the ozone layer.
*Because of this, the Montreal Protocol was initiated in 1987 to prevent the usage of harmful CFCs and begin the recovery process of the ozone layer.*