Lab 12.1

Lab 12.1 – The Climate Change and Fire Connection

 

Wildfires require the alignment of a number of factors, including high temperatures, low humidity, and the lack of moisture in fuels, such as trees, shrubs, grasses, and forest debris. An average annual temperature increase of just 1℃ increases the land area burned by 600%. Additionally, drier conditions produce a longer fire season.

Climate Fire Feedback Loop:

Let’s examine the Climate-Wildfire Feedback loop, but first, recall what a feedback loop is. A feedback loop is a process where a system’s output affects its own input, creating a loop. There are two types: positive and negative feedback loops. In both cases, the feedback loop affects the system’s behavior, either amplifying or dampening changes.

Positive Feedback Loop

A positive feedback loop amplifies a change, making it bigger. Think of a snowball rolling down a hill, gaining size and speed.

Example:

1. Arctic ice melts due to global warming.
2. Less ice means more dark ocean water is exposed.
3. Dark water absorbs more heat from the sun.
4. The increased heat melts more ice.

In other words, the processes in this loop accelerate the melting process.

Negative Feedback Loop

A negative feedback loop reduces a change, stabilizing the system. Think of a thermostat that cools or heats a room to maintain a set temperature.

Example:

1. A forest fire starts and spreads.
2. The fire burns trees, reducing fuel.
3. With less fuel, the fire slows down or goes out.
4. The reduced fire activity allows trees to regrow.

This loop helps stabilize the forest ecosystem.

Quick Check Questions:

Wildfires require the alignment of a number of factors, including warmer temperatures, low humidity, and the lack of moisture in fuels, such as trees, shrubs, grasses, and forest debris.

An average annual temperature increase of just 1℃, increases the land area burned by 600%. Additionally, drier conditions produce a longer fire season. Although many fires are started by lightning and other natural causes, 80% of fires are started by people. Forest fires create extensive plumes of smoke and ash, many of which may move over marine environments. Evidence suggests that the influx of nutrients deposited by smoke plumes may, under the right conditions, allow for the formation of marine algal blooms. The extent of the bloom depends on many factors in the marine environment. In this lab, we will explore the impacts of the 2020 Labor Day Fire as the smoke plume drifted over the Coastal Endurance Array off the coast of Oregon.

 

Comprehension Questions:

1. Is the climate change-wildfire feedback loop positive or negative? Explain your answer.
2. Explain the relationship between climate change and fire. How do hotter drier conditions lead to more intense fires?
3. The planet has warmed an average of 0.06 degrees C per decade since 1983. In 1983, 1,323,666 acres burned. In 2024, 8,924,884 acres burned in wildfires. What is the percent change in the acres burned by wildfires between 1983 and 2024? Show your work.

Percent change = (new value – original value)*/ original value x 100.

* note that using order of operations, operations in parentheses are completed first

If you need some help remembering how to calculate percent change, here is a a video tutorial for reference. Need additional help, click here for a video to walk you through the process of calculating percent change.