Could we be facing a rapid destruction of the world’s forests?

Smoke and flames rise from an illegally lit fire in an Amazon rainforest reserve, south of

Novo Progresso in Para State, Brazil, in August. Photograph: Carl de Souza/AFP/Getty Images

By Michael Coppola
and Nancy Williams
For the past months the news has been filled with articles describing the massive wildfires going on around the world in their increasing numbers, size and intensity. They are being reported in Russia, Brazil, and of course the United States, in both California and Colorado. The question is why more, larger, frequent and intense fires and not the same amount that has been naturally occurring for millennia.
NASA reports “Abnormally warm temperatures have spawned an intense fire season in eastern Siberia this summer. Satellite data show that fires have been more abundant, more widespread, and produced more carbon emissions than recent seasons.”
The Guardian reports, fires in Brazil’s Amazon “increased 13% in the first nine months of the year compared with a year ago, as the rainforest region experiences its worst rash of blazes in a decade.” It’s gotten worse from there, September data from space research agency Inpe has recorded 32,017 hotspots in the world’s largest rainforest, a 61% rise from the same month in 2019.
This is what NASA has to say about our wildfires: “For much of the United States around and west of the Rocky Mountains, the summer and autumn of 2020 have been rough. Nearly 80 percent of the region is facing some level of drought, affecting 40 million people. Heat waves have intermittently baked various regions of the Southwest. And wildfires have raged, fueled by unusual lightning storms, parched vegetation, and other hints of a changing climate. The natural drama has been punctuated by the fact that Colorado and California have set records for the largest fires (by area) in each state’s history.”
These events are harbingers of an occurrence scientists call tipping points. A tipping point is a point in time where conditions stop changing at a slow steady rate and begin to accelerate at a rapid rate and causes a catastrophic change. It is similar to a small leak in a dam that gets slowly larger then starts to rapidly increase in size until it becomes so large that the entire dam collapses.
Currently scientists have recognized nine climate tipping points each of which on its own or in conjunction with others can lead to an existential threat to life on the planet as we know it. The current destruction of the world's forests by fire is one such tipping point. In order to understand tipping points we need to look at the method and terms scientists use when studying climate change. Climate scientists refer to events that cause changes to the climate system as "forcings." These forcing events either feed back into the system more heat, termed positive feedback; or feed back a reduction in the heat, termed negative feedback. These forcings or feedback are key to understanding how climate change events change over time.
Since forest fires are the prominent event in the news let's look at feedback events that forest fires have and how they can lead to a tipping point. When a forest fire burns the heat from the fire evaporates the moisture out of the ground. This moisture enters the atmosphere as water vapor, a very potent greenhouse gas. The atmosphere gains heat as the additional water vapor absorbs long wave radiation. This is a positive feedback.
Another result of the fire is that the soil and plant matter remaining after the fire is very dark in color. This reduces the reflectivity of the surface and allows it to absorb sunlight and heat up. The air comes into contact with the hot ground causing the air to rise up. The hot rising air forms dry thunderstorms. A dry thunderstorm is a thunderstorm that produces thunder and lightning but most or all of its precipitation evaporates before reaching the ground. What does reach the ground is the lightning, which easily starts new fires. This is one more feedback event making the hole in the proverbial dam larger.
Because the burnt dark ground is now absorbing sunlight and heating up it also produces long wave radiation which gets absorbed by the greenhouse gasses. This becomes another positive feedback on top of the previous ones. Yet another is as forests are destroyed by fires there are less plants available to capture carbon. Less carbon capture permits more heating of the atmosphere. The burning of the forest materials also releases large amounts of combustion gasses into the atmosphere, which are greenhouse gasses. Thus increasing the heating capacity of the atmosphere. Yet still another positive feedback. There is one gas, sulfer dioxide, that does provide a cooling effect and could be termed a negative feedback. Since it is easily disolved in water it washes out as acid rain, a serious pollutant to our lakes and oceans.
There is another positive feedback which results from the forest fire. The black soot which rises in the air contains a particle called black carbon which also absorbs the long wave radiation and heats up the atmosphere. The black soot ultimately settles out on the land. In the case of the forest fires in the northern part of Russia the soot has settled on the arctic ice. This reduces the reflectivity of the ice thus allowing it to absorb more sunlight and add heat to the atmosphere, yet one more positive feedback.
The continuous creation of a feedback is referred to as a feedback loop. When we look at the results of all the positive feedback loops that are at work we see why the number, intensity and duration of forest fires have and will continue to increase. The cumulative effect of positive feedback loops are what lead to a tipping point, or the bursting of the dam, in this case the very rapid destruction of the world’s forest.
Many scientists have made the assumption that the tipping points will occur because not enough is being done to stop the feedback loops. Several are now focusing on trying to determine when the tipping points will occur. At this time, nine climate tipping points have been identified. In order for the world's nations to prepare for the changes that will occur due to global warming they will need to know if they have 30 years or only 10 years to take actions to protect their country.
Unless we take bold and quick steps to reduce the heating of the atmosphere, and the amount of greenhouse gasses going into the atmosphere, we will reach those tipping points. You have the power to prevent this. First reduce your carbon footprint by conservation methods. Second, we can decrease the greenhouse gas effect by generating less long wave radiation back to the atmosphere. Think about the surfaces that generate heat. Is your roof a dark color? Make it a light color. Is your driveway black? Paint it white and keep it clean. This will improve your Cool Factor™ in your home and life. (Cool Factor ™ is a reference to a measurement of the sun’s reflectivity on surfaces in your home, car, yard driveway etc. Development of this concept will be discussed in more detail in future articles.) Thirdly, we can all help capture carbon from the atmosphere by planting more trees and shrubs. The shade from your trees will also provide shade to your little square of the planet helping to keep the planet cool. These individual changes we make can prevent the forest fire tipping points and other climate tipping points from occurring. Do your part to save the planet today!