The Biggest Myth

Climate change skeptics most commonly used line of reasoning to combat the reality of human caused global warming is that climate is always changing and that current trends reflect a normal, natural process, as opposed to a dramatic and dangerous human-caused process.  As a well-known climate skeptic Richard Lindzen has stated: “climate is always changing.  We have had ice ages and warmer periods when alligators were found in Spitzbergen.  Ice ages have occurred in a hundred thousand year cycle for the last 700 thousand years, and there have been previous periods that appear to have been warmer than the present despite CO2 levels being lower than they are now.  More recently, we have had the medieval warm period and the little ice age.”  He continues to defend this position and lend his professional credibility to politicians who want to prevent change.

However, this line of reasoning has a substantial flaw; although climate has changed in the past as a result of natural processes, the rate of change hasn’t been this rapid in millions of years (if not longer).  The rate of change over the past 200-250 years has been so rapid because humans are altering the chemical composition of the atmosphere at an unparalleled pace (as stated in a recent Advanced Apes Podcast) (all podcasts can be found here and here)

How are humans doing that?

It is pretty straightforward: greenhouse gas emissions (Karl & Trenberth, 2003).  During the Industrial Revolution (1750-1850 C.E.) humans (primarily in Western Europe, North America and Japan) began burning fossil fuels (e.g., coal, oil) for energy, which resulted in profound changes in agriculture, manufacturing, mining and transportation.  This revolution represented a turning point in human history because it raised the standard of living for a significant proportion of the human population.  As the industrial revolution intensified and spread throughout the rest of the world the global standard of living (e.g., higher life expectancy, lower infant mortality, decreased morbidity, etc.) continued to improve (Maddison, 2003).  However, this revolution and the fossil fuels that allowed it have come with consequences that we will confront in the 21st century: climate change.

What are fossil fuels?

Fossil fuels are actually buried dead organisms (plants) that have undergone a process of anaerobic decomposition, and although we can burn them for energy, they are both finite and primarily composed of the greenhouse gas carbon.  Carbon is not an inherently bad molecule (a fact climate change skeptics consistently use to ‘debunk’ global warming ‘alarmists) but a planet can have ‘too much of a good thing’.  Carbon dioxide is one of the greenhouse gases (along with water vapour, methane, nitrous oxide and ozone) that strongly regulate the Earth’s atmosphere and temperature.  Throughout the Holocene and Pleistocene carbon dioxide existed in the atmosphere at a rate approximately 280 ppm.  Sometimes it would be a little higher, and sometimes a little lower, but it remained fairly constant.  Over the last 250 years the rate has increased from 280 ppm to 397 ppm.  It continues to rise and this is a significant rise that is directly attributable to the burning of fossil fuels, which comprise approximately 86% of the world’s energy source (EIA International Energy Statistics, 2007).

The Big Picture

If we do not curb our emissions we should expect to increase carbon dioxide to 560 ppm which would result in a global temperature 2-4.5 C higher than the pre-industrial levels.  Although that may not seem like a significant rise it would fundamentally change our planet, and would pose a terrible risk to our civilization.  There would be no arctic sea ice and almost no glaciers, which would lead to a dramatic sea level rise displacing millions and destroying global infrastructure.  Many of the most populous cities (e.g., New York, Hong Kong, Shanghai, Karachi, Mumbai, Beijing, São Paulo, Tianjin, Guangzhou, Seoul, etc.) are located on the shores of oceans and would need to be completely relocated.  North American super-storms would become the norm (as we just recently saw with Hurricane Sandy), as would Southeast Asian and East Asian super-storms due to rising global temperature.  Ocean acidification would lead to the collapse of ocean ecosystems and many land-based ecosystems would also collapse.  Although most scientific reports suggest that it is unlikely anthropogenic activities could lead to a runaway greenhouse effect (as happened to Venus), previous scientific reports on the effects of global warming have been overly optimistic, and we can’t dismiss the possibility.

Changing is a win-win

The most important point to stress is that even if the 98% scientific consensus is wrong (which it is not), restructuring our energy economy is a necessity anyway.  If we do not wean ourselves off of fossil fuels, our economy will collapse when they are all gone.  As I stated above, fossil fuels are a finite resource.  Our future energy economy must transition to renewable energy resources anyway, we just have the added pressure of transitioning sooner rather than later because if we don’t we may destroy the planet that has allowed our existence.

temperature1000years

References

Karl & Trenberth.  2003.  Modern global climate change.  Science, 302: 1719-23.

Maddison, A.  2003.  The World Economy: Historical Statistics.  Paris: Development Centre, OECD.  pp. 256-62.

U.S. EIA International Energy Statistics (Retrieved Oct 31 2012)

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About Cadell Last
I am a science educator, freelance science writer, and founder of The Advanced Apes based in Toronto, Ontario. In the past my academic research focused on the evolution, ecology, and behaviour of non-human primates (i.e., chimpanzees, gorillas, ring-tailed lemurs). Currently, my official blog, The Ratchet, can be found via The Advanced Apes and Svbtle. I enjoy exploring recent research in human evolutionary sciences, as well as biology, ecology, astronomy, physics, and computer science. My work has been featured in Scientific American, American Humanist, Richard Dawkins Foundation for Reason and Science, and Jane Goodall Institute of Canada. I am also exploring science popularization in new mediums in collaboration with PBS Digital Studios with an animated YouTube channel. You can contact me on Twitter (@cadelllast) or via email: cadell.last@gmail.com

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