The Amazon fires have finally started to garner the attention of the world. The wildfires and deforestation, mostly in Brazil, are an ecological, political, and societal disaster. The rainforest ecosystem provides oxygen, takes in carbon dioxide, supplies water vapor for the global weather-climate system, and hosts untapped medicinal benefits. The loss of trees and the sun-blotting smoke are obvious consequences of these massive fires. However, there is another problem with these wildfires. They are emitting a lot of carbon monoxide. Here’s why that is a problem.
I suspect that most people have some familiarity with carbon monoxide because it can be harmful to humans. If exposed to it for even short period of time, carbon monoxide can quickly replace oxygen in the blood, which can cause serious or even fatal outcomes according to the Occupational Safety and Health Administration (OSHA). The gas is odorless, colorless, and tasteless so it is particularly dangerous.
According to a NASA press release from the Jet Propulsion Laboratory this week, the carbon monoxide signature of the Amazonian fires are clearly detectable by specialized Earth-monitoring satellites. The image above was captured by an instrument called the Atmospheric Infrared Sounder (AIRS) aboard the Aqua satellite. During my time as a scientist at NASA, I remember how excited we were about the instruments on Aqua (and its counterpart Terra) because of the diversity of Earth System science measurements they would provide. For a dynamic look at how the wildfire-emitted carbon dioxide plume is moving, click this link for a stunning animation from NASA. In the animation, it is clear that the plume of carbon monoxide starts in the region of burning fires and then drifts southeastward into Brazil and other parts of the continent.
A pollutant that can travel large distances, carbon monoxide can persist in the atmosphere for about a month. At the high altitude mapped in these images, the gas has little effect on the air we breathe; however, strong winds can carry it downward to where it can significantly impact air quality. Carbon monoxide plays a role in both air pollution and climate change.
The graphic below shows global concentrations of upper level carbon monoxide during the month of September 2015. According to the NASA Earth Observatory website:
These maps show monthly averages of global concentrations of tropospheric carbon monoxide at an altitude of about 12,000 feet. The data were collected by the MOPITT (Measurements Of Pollution In The Troposphere) sensor on NASA’s Terra satellite. In Africa, for example, the seasonal shifts in carbon monoxide are tied to the widespread agricultural burning that shifts north and south of the equator with the seasons. Fires are an important source of carbon monoxide pollution in other regions of the Southern Hemisphere, such as the Amazon and Southeast Asia
Thankfully, carbon monoxide is a trace gas, and its concentrations are measured in parts per billion by volume (ppbv).
Carbon monoxide, unlike carbon dioxide or methane, does not have as direct of an effect on global temperatures. However, it can be problematic in its own way. When combined with other pollutants and sunlight, it helps to cook up a harmful “stew” of photochemical smog (“bad ozone”), particularly in urban areas where carbon monoxide values can be high.
Most people probably confuse “smog” and “photochemical smog.” Many decades ago, the term “smog” originated from observations of “smoke+fog” in places like London. This is what people likely identify as “normal smog.” It is highly associated with burning high sulfur-content coal, for example. Photochemical smog, what we more commonly deal with in major urban areas, is associated with vehicle and related human activities. It gets “cooked up” by the sun. This is one of the very reasons that on bad air quality days, we are advised to get gasoline after the sun goes down. That “stew” of photochemical smog consists of ground-level ozone (we like it in the stratosphere but not at the surface), particulate matter, carbon monoxide, nitrogen oxides, volatile organic compounds (VOCs), and sulfur dioxides.
The wildfires in Amazon demonstrate how our Earth is connected through so many systems and that there are serious implications.