Reading for understanding Skill Drill
Directions: Read the passage below and complete the questions that follow.
What’s happening with the climate now? Why are we concerned about it?
Isn’t climate change supposed to be a natural process as evidenced by history? As stated above, it does occur every 100,000 years and humans haven’t been around that long. While there is truth to the cyclic nature of climate change, a point has come in history when these changes are no longer natural, but anthropogenic, meaning humans are directly responsible for the current climate change. One of the most significant effects we have on our environment is our large quantity of greenhouse gas emission, mainly carbon emissions. How does this influence our temperature? It all comes down to the greenhouse effect. Carbon dioxide, ozone, nitric oxide, water vapor, and many other chemicals are called greenhouse gasses. They have the ability to absorb thermal infrared waves (heat energy) - a wavelength of light that we can’t see. When these gasses accumulate in the atmosphere, they tend to trap these light waves and reflect them back to the earth, therefore causing the surface temperature to rise. Under normal circumstances, the greenhouse effect is vital for our survival as it’s a natural process that keeps the Earth warm enough for life. However, when humans enhance the greenhouse gas effect,global warming occurs.
How do we know that our CO2 emissions are going into the atmosphere and causing these problems? Using different technologies to measure CO2 levels from hundreds of thousands years ago until the modern-day, scientists have collected data that indicates a sharp rise in CO2 levels after the industrial revolution. This is not just a coincidence; the industrial revolution not only marked the advancement of modern-day technology, but also the start of an era of uncontrolled fossil fuel usage (fossil fuels are fuels found naturally in the earth like coal, oil, and natural gas that are formed from decaying organisms over millions of years). Another way we contribute CO2 to the atmosphere is through deforestation. Plants are great CO2 sinks, meaning they are able to absorb atmospheric CO2 to grow and perform photosynthesis (creation of sugar from water CO2 and sunlight). We have caused considerable environmental damage through deforestation. 32 million acres of rainforest are chopped down per year and this has two effects. First, the CO2 stored inside the trees is released into the atmosphere (Scheer, 2012). Second, the trees are no longer able to perform photosynthesis by absorbing the CO2 and therefore, more is left in the atmosphere.
The level of CO2 is measured in parts per million (ppm), or how many CO2 molecules exist in a sample of one million molecules of air. Dating back 400,000 years ago, the levels of CO2 increased and decreased, but never exceeded 300 ppm. Yet in the last few centuries, CO2 levels have steadily skyrocketed to our present day value of 403.28 ppm (Global Climate Change, n.d.). To put things into perspective, the rate of current warming is 8 times faster than ice age recovery warming (Lindsey, 2010).
Why are we so concerned about 1.4◦F?
The unequivocal evidence is accompanied by a slew of modern-day consequences. Sure, a 1.4◦F increase in temperature might seem miniscule, but in retrospect, the difference in global temperature between glacial and interglacial ages is also just a few degrees (Palfreman, 2000). Today, the result of this temperature difference is observed in the rising sea levels as the arctic glaciers melt, extreme weather events occur across the globe, and oceans are undergoing acidification, just to name a few (Shaftel, 2016). Dire consequences are associated with each event. Melting of the glaciers not only threatens the polar species’ habitats but also increases darker land surface area (ice which reflects light melts to expose the darker, non-reflective ground), which is more prone to absorb heat. This positive feedback event (the previous event increases the severity of the next and so on) of increasing landmass ends up warming the planet (Palfreman, 2000). Extreme weather patterns such as increased droughts and intense rainfalls can pose challenges to agriculture, and cause famine and floods in many areas of the world. Acidification of the ocean endangers marine organisms that produce calcium carbonate shells or skeletons by reducing their ability to synthesize calcium related structures—diminishing coral reefs is the perfect example
Short Answer Questions
1. How often do ice ages usually occur? 
2. Why is the global temperature increasing? 
3. According to the passage, climate change is a natural process. What is the anomaly with our current temperature change? 
4. Identify the discussed consequences of global warming? [4 pts]
Consequence of Global Warmin (Write 4 points)
5. Using context clues define the following words: [1pt]