By Olivia Hakan
When most people hear the words “global warming” or “climate change” they probably think of melting icebergs, extreme heat, and maybe even increased carbon dioxide levels. But how do we know that we have caused increased CO2 levels? What do all of these events mean? And why should we even care about melting ice?
How do we know that human activity has increased carbon dioxide levels?
Over the past century, scientists have been using ice cores from glaciers in the arctic and antarctic circles to determine various qualities about our world. Some of these include carbon dioxide levels, methane levels, temperature, and other aspects of climate. The ice in these samples is incredibly old and contains bubbles of air that preserve small samples of the atmosphere from other time periods. Using these we can directly measure the concentrations of gases in the atmosphere at that point in time (Ice Cores and Climate Change, 2014). It is from this ice core data that we can accurately say that the levels of carbon dioxide in the atmosphere are higher than ever before in history, a phenomenon that is certainly linked to human production of CO2. In fact, humans have altered the earth so drastically that we have essentially become our own geological force, transitioning the earth from the Holocene to the new geological era of the Anthropocene (see Image 1).
What does this mean?
In the simplest sense, due to the increased and continuously rising carbon dioxide levels in our atmosphere, our planet is slowly warming up. Greenhouse gases in the Earth’s atmosphere absorb and trap energy from the sun and re-radiate it, keeping the Earth warm. So, when we have increased greenhouse gases, we also have increased temperatures, which cause the melting of glaciers, increased sea levels, increased extreme events, and an overall shift of the global climate. Every year, due to this increased average temperature, glaciers lose more ice, so much that in the not too distant future we will have an essentially ice-free arctic (Kerr, 2012). In just thirty years, the volume of ice on Earth has decreased by approximately 75%. And recently, in Canada, receding glaciers have revealed landscapes that carbon dating determined had been covered in ice for 40,000 years, (Pendleton).
Why do we care?
All this ice has to go somewhere, and as expected, it melts into the ocean, causing rises in sea level. Though a rise of only a few feet may not sound like much, it will have devastating impacts on both coastal and glacial based communities around the globe. Climate change is not just melting glaciers. It is creating severely disruptive and long-lasting impacts to many different communities.
At this point, humans have altered the Earth’s climate so much that we are no longer sure if it can support life in the long-term future. Living in the Anthropocene means living in an impoverished, hotter, and more catastrophic atmosphere. And, potentially most alarming, living in the anthropocene means living during the sixth major extinction, which has already begun (Ceballos, Ehrlich & Dirzo, 2017).
Humans have created a serious predicament for ourselves, one that may start with, but goes beyond just the melting of our glaciers. There is no way to get out of this predicament but to navigate through it we must do our best to mitigate climate change and decarbonize. That being said, we can’t do anything to “save the planet,” Earth will continue to exist no matter what we do, humans are only a miniscule blip in the massive time scale of this planet. We must try and do our part to mitigate climate change in order to improve the quality of life current and future generations will have, to save the unique species that are already dying off, and to try and undo some of the damage we have done to the planet that gives us everything.
References:
Ceballos, G., Ehrlich, P. R., & Dirzo, R. (2017). Biological annihilation via the ongoing sixth mass extinction signaled by vertebrate population losses and declines. PNAS,114(30). https://doi.org/10.1073/pnas.1704949114
Graphic: The relentless rise of carbon dioxide – Climate Change: Vital Signs of the Planet. (2016, November 08). Retrieved February 13, 2019, from
Ice cores and climate change. (2014, March 1). Retrieved February 13, 2019, from https://www.bas.ac.uk/data/our-data/publication/ice-cores-and-climate-change/
Kerr, R. A. (2012). Ice-Free Arctic Sea May Be Years, Not Decades, Away. Science,337(6102), 1591-1591. doi:10.1126/science.337.6102.1591
Pendleton, S. L., Miller, G. H., Lifton, N., Lehman, S. J., Southon, J., Crump, S. E., & Anderson, R. S. (2019). Rapidly receding Arctic Canada glaciers revealing landscapes continuously ice-covered for more than 40,000 years. Nature Communications,10(1). doi:10.1038/s41467-019-08307-w