Dr. S. NeubauerBIOL 335-901
10 September 2018
What do the skeptics say?
Global warming is a tricky subject, well for those who do not believe that it is happening. Many people reject the idea that the climate is changing, while others who are confronted with multiple evidence that the planet is warming know the climate is changing, but refuse to see that humans are the reason. Skeptics believe humans do not have any impact on the warming of the planet; they think that it is all natural. That even if humans did contribute to the warming occurring, it would be outrageously small and certainly would not lead to the Earth being unlivable. It is a good start that these people are believers of climate change; however,they are misinformed on how much humans have contributed to the changing of climate.
Global warming today does indeed have a human fingerprint on it. A big factor in global warming is the increase of carbon dioxide (CO2) levels. Humans have also been burning and destroying large forested land faster and faster (Steig 2004). As skeptics might say, carbon dioxide has been around for a long time so why is it a problem now? It is problematic because more and more is being emitted from the fossil fuels burned by humans and the deforestation (Manning 2006). Carbon dioxide concentration have gone from 280 to almost 380 parts per million (ppm), the unit of which CO2 is measured (Steig 2004).
Oxygen has a negative correlation with carbon dioxide. As CO2 levels increase in the air, oxygen levels fall due to oxygen being taken out of the air to make CO2 (Manning 2006). Measuring the oxygen in the air is one way to show that CO2 levels are rising (Manning 2006). There is another method in determining the concentration of CO2 in the air, and that is with the isotopes of carbon collected in the atmosphere.
Most skeptics would usually be wondering how scientists know it’s the fossil fuel burning ; the deforestation creating the high levels of CO2 in the atmosphere. Scientists can analyze the types of carbon found in the atmosphere. C12 and C13 are the two most common isotopes of carbon in the atmosphere (Steig 2004). If the C13/C12 ratio decreases the CO2 came from fossil fuel burning, which it does (Ghosh 2003). Therefore, the high concentration of CO2 traps more heat and more heat from the sun making the Earth warmer.
At this point, skeptics assume that the sun is the one giving off the heat, so it is not our fault. If the sun was the cause of global warming, the troposphere and the stratosphere would both be warmed, but this is not the case (Santer et al., 2013). The troposphere, the atmospheric layer closer to Earth than the stratosphere layer, is warmer and the stratosphere is cooler (Santer et al., 2013). This warm cool contrast is caused by greenhouse gases in the lower atmosphere trapping the heat, resulting in less heat rising up to the upper atmosphere (Santer et al., 2013). In relation with the atmospheric layers, the tropopause height, the section between the troposphere and the stratosphere, has risen due to human induced changes in greenhouse gases and ozone (Santer et al., 2013). Carbon dioxide is one of the greenhouse gases trapping more and more heat in the atmosphere and not letting it radiate back into space.
All the heat trapped by the atmosphere has to go somewhere. One major place it goes to is into the oceans (Barnett et al., 2005). Data concludes that 84% of the heating on Earth over the past decades has gone into the oceans (Barnett et al., 2005). Inland ice is melting as well due to the warming on Earth (OSS 2014). The melted ice contributes to the fact that the ocean sea level is rising. It all goes back to the high levels of CO2 in the atmosphere causing more than usual heat to be trapped.
Scientists have tried to make models and observation of other possible causes of global warming, but a lot come to the conclusion that there is no other explanation of why the climate path has altered greatly than by anthropogenic (OSS 2014). Global warming is in motion and it is due to the acts of humans. Carbon dioxide levels are at their highest and will continue to increase if nothing is done about it. Accepting that there is a human fingerprint in climate change is a huge step into the future of the human race and an even greater step in finding a solution to global warming.
Barnett, Tim P., et al. “Penetration of Human-Induced Warming into the World’s Oceans.” Science, American Association for the Advancement of Science, 8 July 2005, science.sciencemag.org/content/309/5732/284.
Ghosh, Prosenjit, ” Stable Isotope Ratio Mass Spectrometry in Global Climate Change Research.” International Journal of Mass Spectrometry, 20 May 2013, www.bgc-jena.mpg.de/service/iso_gas_lab/publications/PG_WB_IJMS.pdf.
Manny, AC, and RF Keeling. “Global Oceanic and Land Biotic Carbon Sinks from the Scripps Atmospheric Oxygen Flask Sampling Network.” Research Profiles, 2006, scrippsscholars.ucsd.edu/rkeeling/content/global-oceanic-and-land-biotic-carbon-sinks-scripps-atmospheric-oxygen-flask-sampling-networ.
OSS Foundation. “Human Caused Global Warming.” Human Caused Global Warming, 21 Feb. 2014, ossfoundation.us/projects/environment/global-warming/human-caused.
Santer, Benjamin D., et al. “Human and Natural Influences on the Changing Thermal Structure of the Atmosphere.” PNAS, National Academy of Sciences, 22 Oct. 2013, www.pnas.org/content/110/43/17235.short.
Steig, Eric. “How Do We Know That Recent CO2 Increases Are Due to Human Activities?” RealClimate, 22 Dec. 2004, www.realclimate.org/index.php/archives/2004/12/how-do-we-know-that-recent-cosub2sub-increases-are-due-to-human-activities-updated/.