Climate Change

Introduction to climate change

Climate change has been one of the issues that will define the 21st century. It has become a hotly contested political issue, with those in power debating the validity of climate change’s existence and how one should address it. But let’s take a step back from that and look at the facts. The causes of climate change, the effects of climate change, evidence for climate change, and how we can address climate change.

The causes of climate change

• Manmade Emissions

Global emissions of greenhouse gasses have drastically increased following the Industrial Revolution. Greenhouse gasses like carbon dioxide from fossil fuel consumers (cars, factories, etc.), methane from agriculture, nitrous oxide from fertilizer, and fluorinated gasses from consumer products. These have been proven to be the main contributing factor towards global climate change (see the “How do we know climate change is happening & manmade?” section)

• Natural Causes?

Skeptics of the commonly accepted view that climate change is manmade point towards possible natural factors that might influence the climate like the sun, water vapor, volcanos, or natural variance of the earth’s climate. However, there are many issues with these types of claims. The natural variance of the earth’s climate often takes thousands of years, not a hundred. The sun has slightly decreased in luminosity since the ’70s. Volcanos emit 100 times less CO2 than humans and they are a part of the carbon cycle. Also, water vapor (whilst more potent than carbon dioxide) is not the main cause of climate change. It has been regulated by the water cycle for eons, but when carbon dioxide and other unnatural greenhouse gasses are introduced, the earth gets slightly warmer. This causes more water to evaporate, causing the earth to heat up even more. Think of it like this, carbon dioxide and other greenhouse gasses the thermostat, water vapor is the air conditioner.

The effects of climate change

• Global Warming

The most prominent and talked about aspects of climate change is global warming. Note: Climate change and global warming are two different things. Climate change refers to the overall change of the Earth’s environment and composition, global warming refers to the rise of global temperatures. As manmade pollutants like carbon dioxide make their way to the upper atmosphere, they create a greenhouse effect that warms the planet. This warming has disproportionately affected the northern and southern ice caps, which leads to sea-level rise and many other detrimental effects.

• Sea Level Rise

The melting of ice caps in the northern and southern hemisphere and thermal expansion of water has directly caused the 20 cm (8-inch) sea-level rise since preindustrial times (although there is some variation of that figure in different locations). This sea-level rise has already affected island nations like the Maldives and increased frequencies of floods worldwide. Regardless of the severity, sea level rise has and further will challenge living in costal/low lying areas.

• Ocean Acidification

30-40% of the carbon dioxide released by humans dissolves in the oceans, sometimes in the form of carbonic acid. This decrease in PH has disrupted calcification in corals algae and fauna, significantly reduced available habitat for fish due to coral bleaching, and will affect the environment in many unforeseen ways. These effects will only worsen with time.

• Heatwaves & Desertification

The increasing global temperatures have and will increase instances of desertification and heatwaves. In a world where the population is expected to grow to >11 billion by 2100, this lack of fertile land might have a drastic impact on food insecurity.

How do we know climate change is happening & manmade?

• Historical Discovery

The greenhouse effect was proposed by Joseph Fourier in 1824. However, John Tyndall first measured the infrared absorption and emission of various gasses. The term “greenhouse effect” was coined in 1901.

• Modern Evidence

With the fact that carbon dioxide concentrations have been unnaturally rising, coupled with the unnatural rise of temperature, and the proof of causation between the two; it isn’t hard to draw a line between man-made emissions and climate change.

What can we do to mitigate global warming?

The existential threat of global warming seems to rightfully scare some. The thought of their communities and environment slowly becoming uninhabitable can make anyone’s blood run cold. However, we can control the outcome, like the large variety of possible futures is directly correlated to how fast, and effectively, we switch to a carbon-neutral/negative future. As a society, we must shift our energy sources, fuels, and food production to better fit the Earth’s needs.

Sources:

“Global emissions of greenhouse gasses have drastically increased following the Industrial Revolution.”

Ritchie, H. (2017, May 11). CO2 and Greenhouse Gas Emissions. Our World in Data. https://ourworldindata.org/co2-and-other-greenhouse-gas-emissions

The Causes of Climate Change. Climate Change: Vital Signs of the Planet. https://climate.nasa.gov/causes/

“…like carbon dioxide from fossil fuel consumers (cars, factories, etc.), methane from agriculture, nitrous oxide from fertilizer, and fluorinated gasses from consumer products.“

The Causes of Climate Change. Climate Change: Vital Signs of the Planet. https://climate.nasa.gov/causes/

Global Greenhouse Gas Emissions Data. (2020, September 10). US EPA. https://www.epa.gov/ghgemissions/global-greenhouse-gas-emissions-data

“Natural variance of this scale takes thousands of years, not a hundred.”

Global Warming. (n.d.). NASA Earth Observatory. https://earthobservatory.nasa.gov/features/GlobalWarming/page3.php#:%7E:text=As%20the%20Earth%20moved%20out,Celsius%20over%20about%205%2C000%20years.&text=When%20global%20warming%20has%20happened,years%20to%20warm%205%20degrees.

“The sun actually decreased in luminosity since the 70’s”

The Causes of Climate Change. Climate Change: Vital Signs of the Planet. https://climate.nasa.gov/causes/

“Volcanos emit 100 times less CO2”

Environment Data - U.S. Energy Information Administration (EIA). (0). EIA. https://www.eia.gov/environment/data.php#intl

Carbon degassing from the lithosphere. (2002, June 1). ScienceDirect. https://www.sciencedirect.com/science/article/abs/pii/S092181810200070X

“Also, water vapor (whilst more potent than carbon dioxide) is not the main cause of climate change.”, “Think of it like this, carbon dioxide is the thermostat, water vapor is the air conditioner.”

Dunbar, Brian. Water Vapor Confirmed as Major Player in Climate Change. www.nasa.gov/topics/earth/features/vapor_warming.html.

“As manmade pollutants like carbon dioxide make their way to the upper atmosphere, they create a greenhouse effect that warms the planet. This warming has disproportionately affected the northern and southern ice caps, which leads to sea-level rise and many other detrimental effects.”

“Climate Report 2014.” IPCC, www.ipcc.ch/site/assets/uploads/2018/02/AR5_SYR_FINAL_SPM.pdf.

“…which can lead to sea-level rise…” “8-inches” “challenge for costal/low-lying areas”

“Choices Made Now Are Critical for the Future of Our Ocean and Cryosphere.” IPCC Choices Made Now Are Critical for the Future of Our Ocean and Cryosphere Comments, www.ipcc.ch/2019/09/25/srocc-press-release/.

“The increasing global temperatures have and will increase instances of desertification and heatwaves. In a world where the population is expected to grow to >11 billion by 2100, this lack of fertile land might have a drastic impact on food insecurity.”

Flavelle, Christopher. “Climate Change Threatens the World's Food Supply, United Nations Warns.” The New York Times, The New York Times, 8 Aug. 2019, www.nytimes.com/2019/08/08/climate/climate-change-food-supply.html.

“Special Report on Climate Change and Land.” IPCC, www.ipcc.ch/srccl/chapter/chapter-5/.

“The greenhouse effect was first…”

Lewis, Danny. “Scientists Have Been Talking About Greenhouse Gases for 191 Years.” Smithsonian.com, Smithsonian Institution, 3 Aug. 2015, www.smithsonianmag.com/smart-news/scientists-talking-about-greenhouse-gases-191-years-180956146/.