Throughout my time in the MACAL Climate Science, Impacts and Services course, I’ve been building my climate knowledge and familiarizing myself with credible climate science information sources. Equipped with this information, I would like to share those resources with you and debunk a few common climate change myths:
Myth # 1: The earth has warmed before – it’s a natural cycle.
Short answer: Yes, there have been ups and downs. But this time it’s because of us.
Yes, the earth’s temperature has gone through many ups and downs in the past 540 million years or so: for one thing, our planet has moved back and forth several times through two states known as the hothouse (also called warmhouse or greenhouse) climate and the icehouse (or coolhouse) climate (Green, 2013, as cited in Emanuel, 2020, Chapter 4 video 3). During hothouse periods, the poles were either mostly or completely ice-free and have at times been hospitable for alligators and turtles. Icehouse periods, on the other hand, are characterized by ice at the poles: as you might correctly deduce then, we are currently in an icehouse period. Within an icehouse period, there are also fluctuations in temperature: periods when ice extends over large portions of the continents are known as glacials or glacial periods and we often refer to the last such period as the ice age (although there were in fact several) (Eldredge & Biek, 2010). When those sheets of ice retreat to the poles, the earth moves into an interglacial period, such as the one we are currently in.
So yes, the earth has warmed in the past, but civilization has developed and thrived within an interglacial period of the icehouse climate and more specifically within a particularly stable climatic period known as the Holocene (Emanuel, 2020, p 35). Our civilization is highly dependent on the Holocene’s stable climate to sustain agriculture and ensure adequate food supply for Earth’s population, to mention just one of a host of features that have made the climatic stability of the Holocene both exceptional and critical (Emanuel, 2020, Chapter 8). Because of human activity and CO2 emissions, we are now destabilizing that climate and on a warming path (Emanuel, 2020, p. 20). The Earth has many natural cycles that influence global warming and cooling, but human activities are unequivocally responsible for the current warming (Masson-Delmotte et al., 2021, section A.1). In fact, the earth’s natural cycle would currently have us on a cooling path, were it not for human influence (Emanuel, 2020, p. 20).
Myth # 2: It’s only a few degrees – what’s the big deal?
A 1°C increase in average global temperature is just that – an average. In order for the average global temperature to be one degree higher today compared to the mid 1800s, for example, there will be days and areas of the globe experiencing extreme temperatures that are much higher than a degree above normal, and those unusually high temperatures are often associated with extreme events (Murdock & Tyler, 2019). Certain parts of the globe are also warming faster than others – Canada’s average warming is twice as high as the global average, for example (Bush et al. 2019, p. 5). As well, the ocean takes longer to show signs of global warming than land does and since the average global temperature includes the parts of the globe covered by oceans, the global average underrepresents what we are experiencing on land (Murdock & Tyler, 2021).
Given the current level of warming, the difference of one degree or even half a degree of additional warming also has dramatic repercussions on our climate. To cite a few of the many impacts, as stated in the Intergovernmental Panel on Climate Change (IPCC)’s latest report, the frequency and severity of events such as heatwaves, flooding, droughts and natural disasters such as cyclones are all projected to increase with each incremental amount of warming, “as well as reductions in Arctic sea ice, snow cover and permafrost” (Masson-Delmotte et al., 2021, section B.2).
Myth # 3: Canada is a cold place – we’ll be fine regardless; it might even improve our climate!
While there are a few predicted advantages for Canada with a warming climate, such as a longer growing season and less extreme cold (Bush & al., 2019, p. 5), unfortunately the list of disadvantages far outweighs the positives. As stated in Canada’s Changing Climate Report, the following changes are projected:
- Oceans surrounding Canada have (and will continue to warm), become more acidic, and less oxygenated… These changes threaten the health of marine ecosystems;
- An increased risk of (fresh) water supply shortages in summer;
- Increased severity of heatwaves…increased drought and wildfire risks… more intense rainfalls will increase urban flood risks; and
- Coastal flooding is expected to increase in many areas of Canada due to local sea level rise (Bush & al., 2019, p. 5).
In addition to these changes within our own country, however, the impacts of climate change across the rest of the world will have direct and perhaps even more significant impacts on us. For example, agriculture will be impacted in places outside of our borders that we rely on to grow our food. In the US, climate change is projected to cause agricultural losses that currently occur every 20 years to potentially happen every second year (Emanuel, 2020, Chapter 8 – Figure 19). As well, I agree with the magnitude and importance attributed in the following statement:
Political and social destabilization… is perhaps the greatest and least predictable risk incurred by rapid climate change… climate change could have significant geopolitical impacts around the world, contributing to poverty, environmental degradation, and the further weakening of fragile governments. Climate change will contribute to food and water scarcity, will increase the spread of disease, and may spur or exacerbate mass migration (Emanuel, 2020, p.39).
Whether you look at these global impacts from an ethical and social responsibility perspective or consider how it will personally impact you here at home, climate change-related destabilization in other parts of the world will affect us all. This is a global problem and in an interconnected globalized world, we should and must cooperate to find solutions for the benefit of everyone.
Want to learn more? I encourage you to check out the references from this post for more information on these topics.
References
Bush, E., Gillett, N., Bonsal, B., Cohen, S., Derksen, C., Flato, G., Greenan, B., Shepherd, M., & Zhang, X. (2019). Canada’s Changing Climate Report: Executive Summary – Headline Statements. Environment and Climate Change Canada. https://changingclimate.ca/CCCR2019
Eldredge, S. & Biek, B. (2010) Glad You Asked: Ice Ages – what are they and what causes them? Utah Geological Survey. Survey Notes: Vol. 2. Number 3. https://geology.utah.gov/map-pub/survey-notes/glad-you-asked/ice-ages-what-are-they-and-what-causes-them/
Emanuel, K. (2020). Climate Science, Risk & Solutions: Climate Science for Everyone [Online Interactive Module & PDF document]. Massachusetts Institute of Technology (MIT). https://climateprimer.mit.edu/climate-science/
Masson-Delmotte, V.; Zhai, P.; Pirani, A.; Connors, S.L.; Péan, C.; Berger, S.; Caud, N.; Chen, Y.; Goldfarb, L.; Gomis, M.I.; Huang, M.; Leitzell, K.; Lonnoy, E.; Matthews, J.B.R.; Maycock, T.K.; Waterfield, T.; Yelekçi, O.; Yu, R. & Zhou, B. (eds.) (2021). IPCC, 2021: Summary for Policymakers. In: Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge University Press. In Press. https://www.ipcc.ch/report/ar6/wg1/downloads/report/IPCC_AR6_WGI_SPM.pdf
Murdock, T. & Tyler, K. (2019). Module 1, Part 2 – Using Future Climate Projections [Recorded Presentation]. Pacific Climate Impacts Consortium. https://www.youtube.com/watch?v=0eXyhJ0HiyI
Skeptical Science. (n.d.). Global Warming & Climate Change Myths. https://skepticalscience.com/argument.php Note: Although the website referenced here is a useful resource, I am not endorsing it as a credible climate science source.