Are humans the cause of climate change? Yes. However this is not the question that needs addressing. Why don’t people believe the science on climate change is accurate and want to act on this knowledge to make the planet healthier? That is the trillion dollar question. Being able to reach people who refuse this truth can be difficult but it is a calling we must embrace and champion. We do this every day explaining complex medical theories of disease to patients so they can better appreciate what is wrong in their bodies. One of the age old techniques humans use to communicate complex teachings is through storytelling. By weaving elements of truth, data and consequences into a story, these aspects are more easily remembered and retold, instead of asking someone to memorize and regurgitate facts. Who doesn’t like a good story! So let's learn to tell the story of our planets changing climate and the role humans play.
Once upon a time on a planet called earth, there was a lot of carbon dioxide and other gasses in the atmosphere in our primordial soup of water and storms. At this time, 500 million years ago, life was beginning to evolve with temperatures and atmospheric carbon dioxide levels were much higher than today’s level. Our little baby planet started to have algae, animals, plants and land masses forming which started to sequester some of the carbon from the atmosphere into creatures. During this period 100-300 million years ago, the rainforest stretched from pole to pole and the sea levels were quite high. Dinosaurs and other creatures did not live forever, and as they died some but not all of carbon in their bodies was released into the atmosphere. Algae in the oceans formed and then fell to the ocean floor when it died becoming oil and natural gas. Trees and swamps became buried by the shifting planet turning into coal. Other algae coated themselves in calcium before they died, then fell to the ocean floor. Here they were compacted before being forced upward to the calcium carbonate Cliffs of Dover we see today. This was the OG of carbon sequestration on our planet. With the carbon being removed from the atmosphere and volcanic activity decreasing between 5-50 million years ago, the temperature of the planet started to decrease, approaching our current average temperature. Ice started to form in Antarctica but sea levels were still 30 meters above today's levels. Early humans appeared 1-3 million years ago as this process continued and we reached carbon and temperature levels that are seen today. This cooler planet led to the glacial and ice ages with modern humans between 5 to 500 thousand years ago. It is this moment that is often referenced as a period of natural carbon and temperature variation to explain that our current temperatures are not concerning. Carbon Dioxide levels in this time ranged between 200-300 ppm much less than today’s in the 400’s and the primordial soup levels of 1500 ppm where temperatures reached 12 C above current temperatures.In the last 1000 years our planet became quite settled with temperature and carbon levels that define our baseline, until the industrial revolution. Humans saw the energy density in fossil fuels that was unmatched by any other source making these ideal for manufacturing the high temperatures needed for steel, transportation and energy generation. As we consumed and released these carbon stores into the atmosphere they had not visited in milenia, our planet’s temperature started to rise and rise and rise. Other carbon stores were also released by our behavior including loss of trees, mangroves, and grasslands which led to further release of carbon from the soil. Carbon dioxide is an acid we appreciated from all of our Henderson-Hasselbalch equation studies. Most of our planet is covered by water which directly interacts with our air, leading to more carbon dioxide in our oceans, thus ocean acidification which decreases the oceans ability to store carbon. Systemic release of stored carbon into our atmosphere is taking us on the path back to the primordial soup, and no one wants to go back there.
Sure, but do atmospheric carbon levels relate to temperature? Absolutely. As we track these two variables we find they go up and down together over time. This is not a coincidence, this is a fact we scientists can accept.
Thus as we understand the story of our planet, we see the variations of carbon dioxide over time, how it was stored and released leading to corresponding planetary temperature changes. These variations follow normal cycles, including yearly cycles with lower carbon dioxide levels in spring as the plants sequester carbon in leaves and higher in the fall when the fallen leaves release the carbon back into the sky. However, our use of fossil fuels has thrown off this natural cycle by releasing stored carbon leading to a warmer planet. No bueno my friends.
Next month we will discuss how carbon dioxide energizing our planet leads to health impacts as we understand this disease and develop a plan of care.
