Pinpointing climate change's role in extreme weather
19 September 2020
Climate scientists are increasingly able to use computer models to determine how climate change makes some extreme weather more likely.
Why it matters: Climate change's effects are arguably felt most directly through extreme events. Being able to directly attribute the role climate plays in natural catastrophes can help us better prepare for disasters to come, while driving home the need to tackle greenhouse gas emissions.
Driving the news: The wildfires currently tormenting the West Coast are historic, but they're also part of a measurable surge in fires in recent years.
- Compared to the 1980s, the acreage burned in Western states annually between 2010 and 2019 has more than doubled, according to analysis of government data by Climate Central, a climate science nonprofit.
- Climate change clearly plays a driving role. Research has found that roughly half of the acreage burned since the mid-1980s can be attributed to warming temperatures caused by climate change, notes Matthew Hurteau, an ecologist at the University of New Mexico.
The backstory: It was long the case that scientists were hesitant to link any single event to climate change.
- That's begun to change in recent years as computational power has fallen in price, allowing scientists to run climate models that compare what actually happens in our warming world to a hypothetical planet where climate change never occurred.
- By comparing those models, scientists can determine how much climate change has loaded the dice to make an extreme event more likely.
A newer attribution research method, known as the storyline approach, works more like an autopsy, determining the causes of an extreme event like a storm and indicating whether climate change was one of those causes.
- A study published in January used a storyline approach to examine Hurricane Florence, which struck the Carolinas in 2018, finding that the storm was over five miles wider because of climate change, with rainfall amounts increased by nearly five inches.
It would be a myth for us to say that climate change isn't playing a role in increasing the frequency of some of these billion-dollar disasters.
Adam Smith, applied climatologist, NOAA National Centers for Environmental Information
The bottom line: Climate science has always been future focused, but attribution research allows scientists to see precisely how climate change is hurting us here and now.
Transcripts show George Floyd told police "I can't breathe" over 20 times
Section2Newly released transcripts of bodycam footage from the Minneapolis Police Department show that George Floyd told officers he could not breathe more than 20 times in the moments leading up to his death.
Why it matters: Floyd's killing sparked a national wave of Black Lives Matter protests and an ongoing reckoning over systemic racism in the United States. The transcripts "offer one the most thorough and dramatic accounts" before Floyd's death, The New York Times writes.
The state of play: The transcripts were released as former officer Thomas Lane seeks to have the charges that he aided in Floyd's death thrown out in court, per the Times. He is one of four officers who have been charged.
- The filings also include a 60-page transcript of an interview with Lane. He said he "felt maybe that something was going on" when asked if he believed that Floyd was having a medical emergency at the time.
What the transcripts say:
- Floyd told the officers he was claustrophobic as they tried to get him into the squad car.
- The transcripts also show Floyd saying, "Momma, I love you. Tell my kids I love them. I'm dead."
- Former officer Derek Chauvin, who had his knee on Floyd's neck for over eight minutes, told Floyd, "Then stop talking, stop yelling, it takes a heck of a lot of oxygen to talk."
Read the transcripts via DocumentCloud.