Climate Change: How our Atmosphere Plays a Role in Regulating the Global Climate
Climate change. Global warming. Many of us hear these phrases referenced daily in the news. Most of you are probably familiar with the associated consequences, such as sea level rise, increased droughts, fires, storms, and flooding. But first, what even is global warming and scientifically speaking, how is it happening? And how does this relate to YOUR life?
According to the ICPP, the International Panel on Climate Change, in 2017 the global mean-temperature was 1°C (about 1.8°F) higher than pre-industrial levels (which was only a couple hundred years ago) due to human-related activity. This might not sound significant—yet it is.
We live on a big, blue planet spinning roughly 1,000 miles per hour in space. Thankfully, the Earth is blanketed by our atmosphere, essentially a layer of gases (about 78% nitrogen, 21% oxygen and less than 1% consists of carbon dioxide and other trace elements) that enables us to live and breathe the oxygen we need.
This layer of gases in the atmosphere also allows life to flourish on the planet because it traps some of the sun’s radiation and warms the Earth’s surface.
To simplify: Solar radiation from the sun reaches the Earth and some of it is absorbed by the land and water (which heats these surfaces), while some of it is reflected. But thanks to this layer of gases in the atmosphere, some of that radiation reflected by the Earth is trapped by this “blanket” of gases, which ultimately results in further heating of the Earth’s surface — this is called the ‘Greenhouse Effect.’ This is a natural process and is incredibly important for life as we know it.
How important is this natural greenhouse effect?
According to NASA, the global mean-temperature (average) in 1998 was about 59° Fahrenheit. If this layer of greenhouse gases didn’t exist to trap in some of that solar radiation being reflected by the Earth, the average world temperature would be 0° Fahrenheit. This is not talking about the weather—the short-term temperature differences by day or week. This is referring to the climate—the long term average. And that would be a very cold, long-term average temperature - way too cold for humans.
So, we essentially owe part of our existence to this heat-trapping layer of gases.
This natural Greenhouse Effect is crucial for life on our planet. So why do we hear ‘greenhouse gases’ so often when talking about climate change? Global warming has to do with an increase in greenhouse gases.
We have this blanket - this important layer of gases that lets some heat go but traps enough so that our planet isn’t a giant, uninhabitable ice field. Imagine if we make this blanket thicker. What happens if you put a thicker blanket over you? You trap more heat in. Which is exactly what is happening in our atmosphere.
Gases like carbon dioxide (CO2), methane (CH4), and nitrous oxide are all considered greenhouse gases. When added to the atmosphere, they enhance this greenhouse effect, resulting in a world trapping in more and more heat.
Humans play a role in this warming through activities such as burning fossil fuels which releases mass amounts of CO2, and through agriculture such as raising livestock, which produces methane (a greenhouse gas roughly 30 times more potent than CO2)—just to name a couple.
In the past 4.5 billion years, the planet has gone through many phases of warmer and colder periods, including ice ages and extreme warming events. What is unique about this time, is the rate at which global warming is occurring. The current rate at which CO2 is being emitted into our atmosphere is unprecedented, and CO2 levels in the atmosphere now are greater than during any time in the last 420,000 years.
After all, ‘global warming’ is one of the most common phrases tossed around these days—but how many people actually know what it is and what is causing it? Hopefully now you do, and will be able to explain it to your friend who doesn’t!
Cheers,
AT
Sources:
https://www.ipcc.ch/site/assets/uploads/sites/2/2018/11/SR15_Chapter1_Low_Res.pdf
https://www.giss.nasa.gov/research/briefs/ma_01/
https://www.nature.com/articles/20859