Fact-checking climate change comments in first presidential debate

In this Sept. 3, 2020, photo provided by the Opal Creek Ancient Forest Center, fire retardant is dropped at Jawbone Flats in the Opal Creek Wilderness in Oregon. Oregonians are grieving the loss of some of their most treasured natural places after wildfires wiped out campgrounds, hot springs and wooded retreats that have been a touchstone for generations in a state known for its unspoiled beauty. (Augustus Gleason/Opal Creek Ancient Forest Center via AP) (Augustus Gleason)

Most analysts did not expect climate change to be one of the subjects highlighted by moderator Chris Wallace. But Wallace dropped a bit of a surprise by bringing global warming into the debate. 

Although the candidates did not make many specific comments worth fact checking, there were three that I was able to look into.

Wildfire blame

First, President Trump blamed the western wildfires solely on forest management. This statement is rated as BE CAREFUL. 

Be Careful

After reviewing this topic, we've found some issues - Be Careful.

What is the Trust Index?

While forest management may have some role, the president clearly ignored a definite correlation between the number of large western wildfires and warming temperatures, as can be seen in this research by Climate Central. And this does not even take into account increasing drought out west. 

Hottest years, more fires. (Climate Central)

Put simply, increasingly hot, dry weather out west creates conditions more conducive for wildfires, so it’s much more than just forest management that is causing the increase in large wildfires.

Rainforest claim

Vice President Biden, in highlighting the importance of the Brazilian rainforest in reducing carbon dioxide, said that more carbon dioxide is taken in by the Brazilian rain forest than the U.S. produces every year. This statement is rated as FALSE. 

Not True

After review, we've found this information is Not True.

What is the Trust Index?

While the Amazon rainforest does indeed absorb a tremendous amount of carbon dioxide, its estimated annual total of two billion metric tons of absorbed annual carbon dioxide is less than half of the estimated 5.1 billion metric tons of energy-related carbon dioxide produced by the U.S. every year. There is no questioning that the Amazon is very important in taking in carbon dioxide, but it does not by itself offset the total U.S. carbon dioxide emission.

Iowa storm

To highlight how global warming is causing more destructive storms, Vice President Biden talked about the big storm (called a derecho…pronounced duh-RAY-show) that devastated Iowa this summer, and said that “those didn’t happen before”, because of global warming. This statement is rated as BE CAREFUL

Be Careful

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What is the Trust Index?

Derechos have happened in the past, so the statement itself with no additional context is false. However, global warming IS directly increasing high-impact extreme weather events, which is the point the Vice President was making, as you can see in this data showing, for example, the increase in extreme precipitation events:

U.S. Downpours. (RCC-ACIS)

Hopefully, the upcoming vice presidential and presidential debates will provide more insight into the candidates' thoughts about Earth’s unnaturally warming climate, the ramifications, and what they propose to do (or not do) about it.

More: Trust Index: Fact-checking from first Biden-Trump debate