Amazon fires, deforestation could eventually affect Arizona forests

By Alex Devoid, Arizona Daily Star
As the Amazon burns, a bad situation could get worse for forests in Arizona.

“The relationship is very clear,” said Don Falk, a professor at the University of Arizona.

Deforestation in the Amazon accelerates changes in global climate. And these changes eventually affect forests close to home.

They’re driving longer, warmer and more intense wildfire seasons, he said. And they’ve already fueled unprecedented wildfires in Arizona and across the West.

Tropical forests like the Amazon rarely burn when left to nature, but fire has always had a place in the life cycle of forests in Arizona.

Low-intensity fires in Arizona historically cleared the forest floor, limiting the accumulation of wildfire fuel, while leaving mature trees standing.

In the 1880s, people and livestock started interrupting fire’s place in this cycle, Falk said. Then U.S. federal policies suppressed wildfire for decades staring in the 1920s, allowing fuel to accumulate. Changes to global climate dried it out with drought and higher temperatures.

In the worst cases, flames jumped from the ground to the crowns of densely packed trees.

They engulfed old-growth forests, spreading faster and more destructively through more forest than ever before.

In 2002 and 2003, for example, it happened in the peaks above Tucson on Mount Lemmon during the Bullock Fire and then the Aspen Fire. Since then, hundreds of thousands of acres have burnt this way in Arizona.

The Amazon is an important buffer against the warming climate, which has created the conditions for these unprecedented fires. It absorbs around 2 billion of the 40 billion tons of carbon dioxide emitted globally each year.

At least a quarter of the stored carbon on earth is concentrated in tropical forests like the Amazon, which grow on barely 12% of the earth’s land, Falk said.

Forests fires across the globe may contribute to climate change by burning carbon these forests store, according to a 2015 study by researchers from universities across the country.

As the Amazon burns, for example, it absorbs less carbon dioxide.

Meanwhile, more billows from the flames, warming the planet by trapping heat inside the atmosphere.

“It’s a double hit to the global climate system,” Falk said.

Source: Amazon fires, deforestation could eventually affect Arizona forests- tucson.com, 2019-09-06