When people talk about the climate crisis, what is the alarm bell? What is the one piece of information that gets the most attention? It’s our atmospheric carbon dioxide levels. What was the carbon dioxide (CO2) parts per million (ppm) when you were born? Children today are born into atmospheric CO2 levels of 420ppm (NOAA 2023). Your gut reaction might be that that is a big number and we must be in a crisis of unprecedented levels.
Yet the reality is that it’s not simply how much CO2 is floating around up there. That is an important part, but the truth is that climate change is much more complicated than its elevator pitch suggests. If you’re like me, and one day you’re in class and realize everything you’ve been told about the climate crisis is straight out of “Climate for Dummies”, you have questions. Without knowing the full truth, you might find it easy to discredit the climate crisis, but there are many intricate variables that make anthropogenic climate change something to worry about.
What often goes unsaid is that 420ppm atmospheric carbon dioxide is one of the lowest concentrations known in Earth’s long and tumultuous history. You want some shocking numbers? Look back about 50 million years ago. According to proxy climate data from Texas A&M, 50 million years ago the atmospheric CO2 was 1,500ppm and there were alligators in Antarctica (Rae et al. 2021).
Climate change is an inevitable process. Our planet is always changing and always destined to change out of what we consider “normal” conditions. During the Quaternary glacial/interglacial cycles, the temperature fluctuated by roughly 5C. That was long before humans and yet everything was fine, so what’s the big deal?
The big deal is that we are on track to change Earth’s temperature by ~4C in 300 years when a natural rate of change of that magnitude would take 5,000 years (Mukherji et al. n.d.). The predicted rate of change for the next century is 20x faster than any historical climate change (“RealClimate” 2007).
The reason the rate of change is important is because of this little thing called evolution. Evolution takes hundreds to thousands of years to adapt a population to changing environmental conditions. This, of course, depends on a variety of factors like reproductive rate and selective pressures on a given population. The reason that life thrived during such massive climactic fluctuations throughout history is because it had thousands of years to adjust. Life prior to humans did not, metaphorically, wake up one morning and get slapped in the face with the Industrial Revolution. But now there is no time for life to change to suit the new climate. Anthropogenic influence on climate is a rapid shock to the well-oiled machine that is Earth as a system. Our wildlife cannot keep up and we find ourselves in a sixth mass extinction (Barnosky et al. 2011).
Mother Earth does not care about our diminutive measurement of time. This rate of change is astronomical in Earth’s history. Humans have been around for ~300,000 years – approximately 1 second of Earth’s long life – and we have altered it far beyond any other single factor in its history.
I digress, but obviously the Earth was capable of dealing with 1,500ppm without everything falling apart, so why should we care?
In a healthy Earth system, yes, the Earth is capable of equalizing and responding to much higher atmospheric CO2. Earth has an incredible capacity for stabilizing itself, but unfortunately, we’ve bungled that pretty bad as well.
The reason we are seeing so many major changes in our system at such comparatively low CO2 levels is that we have managed to damage nearly every single factor in the equation that might save us. Historically, the oceans, forests, and soil were able to stabilize atmospheric carbon as carbon sinks. However, we’ve destroyed most of our soil or developed over it, have removed 420 million hectares of global forest since 1990, and the ocean has absorbed so much carbon it is becoming acidic (Doney et al. 2009, Global Forest Resources Assessment 2020). All of the natural checks and balances that nature has developed over millennia are very rapidly being unraveled. Everything is so beautifully interconnected, and we have pulled at the strings in nature’s tapestry. Our planet is full of biotic and abiotic feedback loops and complex relationships that expand far beyond what we could ever hope to understand or control. That’s part of what makes it so remarkable.
Evidence of our planet’s changes can be found in every aspect of the natural world. Stronger and more frequent natural disasters, extreme temperatures, disease, algal blooms and disappearing coral. The 2023 IPCC report states that if warming is limited to 2C then sea level will rise by 1 meter in the next 80 years. Even if we ceased CO2 emissions tomorrow, the results of the damage we have already done will linger for thousands of years. With no more anthropogenic influence, sea level is still predicted to rise by 6 meters within the next 2,000 years (IPCC, 2023). But unfortunately, our CO2 emissions will not stop tomorrow, we won’t stop producing plastics or chopping down our forests. With lack of decisive and revolutionary changes to our society, climate change and all of its side effects will get worse. That is the inevitable truth that people do not like to hear.
Life has a great capacity for resiliency and will, in some form, adapt. So then, why should we care if the planet is inevitably changing? Dr. Brittany Hupp, a renowned paleoclimatology researcher says, “If climate continues to change, the Earth will be here, organisms will be here. Ultimately, it is people who will suffer. Why care about anthropogenic climate change? To be blunt, if you care about people.”
The reality of our situation, when truly absorbed, is enough to make you turn away and give up. I understand why people don’t talk about how dire our situation really is. People stop trying to change something they believe they have no control over.
But then I realized that some things are inevitable. The Earth will spin long after we are gone; whether we are here to see it is up to us. In the end we will not defy the laws of nature and existence, but maybe we can make life better for our children and their children. We can’t save what we’ve already lost, but we can slow the rate of change. Humanity would survive, and regardless of how we respond, the planet will recover, and life will continue to live. There is, at least I find, some security in that.
The situation is not at all lost. We are running out of time, true, but we still have time left. The science and the solutions exist and have been proven successful. There are ample opportunities for constructive change. Each person may feel like a small fry, but keeping yourself informed of the science and where you can take action is the single best step you can take. Educate yourself and others and maybe we can tackle this battle together.
References
Barnosky, A. D., N. Matzke, S. Tomiya, G. O. U. Wogan, B. Swartz, T. B. Quental, C. Marshall, J. L. McGuire, E. L. Lindsey, K. C. Maguire, B. Mersey, and E. A. Ferrer. 2011. Has the Earth’s sixth mass extinction already arrived? Nature 471:51–57.
Doney, S. C., V. J. Fabry, R. A. Feely, and J. A. Kleypas. 2009. Ocean Acidification: The Other CO2 Problem. Annual Review of Marine Science 1:169–192.
Global Forest Resources Assessment 2020. 2020. . FAO.
Mukherji, A., P. Thorne, W. W. L. Cheung, S. L. Connors, M. Garschagen, O. Geden, B. Hayward, N. P. Simpson, E. Totin, K. Blok, S. Eriksen, E. Fischer, G. Garner, C. Guivarch, M. Haasnoot, T. Hermans, D. Ley, J. Lewis, Z. Nicholls, L. Niamir, S. Szopa, B. Trewin, M. Howden, C. Méndez, J. Pereira, R. Pichs, S. K. Rose, Y. Saheb, R. Sánchez, C. Xiao, and N. Yassaa. (n.d.). SYNTHESIS REPORT OF THE IPCC SIXTH ASSESSMENT REPORT (AR6).
NOAA. 2023, May 9. Global Monitoring Laboratory – Carbon Cycle Greenhouse Gases. https://gml.noaa.gov/ccgg/trends/.
Rae, J. W. B., Y. G. Zhang, X. Liu, G. L. Foster, H. M. Stoll, and R. D. M. Whiteford. 2021. Atmospheric CO2 over the Past 66 Million Years from Marine Archives. Annual Review of Earth and Planetary Sciences 49:609–641.
RealClimate: Database. 2007, May 22. . https://www.realclimate.org/index.php/archives/2007/05/start-here/.
Thank you to:
Dr. Paul Betka, Professor at George Mason University, Geosciences
Dr. Brittany Hupp, Assistant Professor at George Mason University, Marine Paleoclimatology
Dr. Courtney Massie, Assistant Director of George Mason University Writing Center, Editor