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Illustration: Aïda Amer/Axios
In the blitz of media coverage following the Trump administration's Black Friday release of the Fourth National Climate Assessment (NCA4), one statistic kept popping up:
By the end of the century, global warming could cost the U.S. 10% of its gross domestic product.
I spent part of this week tracking down the origins of that frightening statistic.
Why it matters: This figure has been used to indicate that global warming will inflict massive economic costs on the U.S. if dramatic actions to adapt to climate change and curtail emissions are not taken in the next decade.
Background: The stat can be traced to a 2017 study, published in the journal Science, that quantified the economic costs to the U.S. for various amounts of climate change.
Amir Jina, an economist at the University of Chicago and a co-author of that study, told Axios he was not surprised the 10% statistic was used in the NCA4, but he has been "a little disappointed" at how the media focused on it.
"I still obviously stand by the work that we did, and that number does come from this paper, but I think it needs more nuance in the way that it’s presented,” Jina told Axios.
Details: The study, based on a meta-analysis of the peer reviewed literature as well as extensive new modeling, projects that nationwide, for every 1°C increase in average temperature, U.S. GDP will drop by 1.2%.
Funding: Jina, and lead author Solomon Hsiang of U.C. Berkeley, told Axios the 2017 study moved the science well beyond findings of earlier work Steyer and Bloomberg funded and mainly relied on other sources.
Hsiang also said the funders had no input on the study's conclusions.
It's not an outlier: Michael Oppenheimer, a geosciences researcher at Princeton and study co-author, told Axios that the cost estimates included in the NCA4 would be similar even if this study was not in it, given other work on the topic.
He Jiankui speaking Nov. 28 at the Second International Summit on Human Genome Editing. Photo: Zhang Wei/Chinese News Service/VCG via Getty Images
China is temporarily suspending the work of scientists who claimed twins were born after being genetically edited as embryos.
Why it matters: The scientific consensus is that gene editing embryos at this stage of science is "irresponsible." But, while this particular experiment has not been verified, the fact is the technology is available to researchers, so there's a growing call for international limitations on its use.
ICYMI: Chinese scientist He Jiankui announced earlier this week that twins were born after he used the gene-editing tool CRISPR-Cas9 to cut the CCR5 gene that's known to play a role in HIV infection.
Between the lines: Not everyone viewed it as a complete disaster. For instance, Harvard Medical School's George Daley suggested that it may be time to reconsider the massive amounts of research done over the past several years and look for plausible methods of moving forward.
What to watch: Scientists are cautious about predicting what the impact will be, in part because the details of this claim are thin. However, the debate is heating up and one concern is it will dampen important research.
The bottom line: The alarm over what could be next is real. But scientists hope the current debate will promote consensus on firm limits and promote transparency.
One of the key questions addressed in the Fourth National Climate Assessment is one of timing: When will the U.S. begin to feel the impacts of global warming?
The answer is unsettling, because it's past tense.
Why it matters: We're not responding in the ways climate experts hope we will, at least not yet.
“This is a risk management problem par excellence," said Princeton's Oppenheimer. "We would have to be incredibly irresponsible” not to take action in light of what is known about climate change, he said, speaking of both adaptation to climate impacts today and emissions cuts.
The trends: According to a new report from Climate Central and the real estate data firm Zillow, in more than 50% of coastal states, homes are being built at a faster rate in areas at risk of flooding from sea-level rise than the rate of new homes in safer areas.
"It’s difficult to plan for higher seas if you are busy digging deeper holes," said Benjamin Strauss, CEO and chief scientist of Climate Central, in a press release.
The Instrument Deployment Camera, located on the robotic arm of NASA's InSight lander, took this picture of the Martian surface on Nov. 26. Photo: NASA/JPL-Caltech
Life expectancy: Spurred by a spike in suicide, overdose deaths and hunger, life expectancy in the U.S. has been declining for the past three years.
Global goals: The UN's goal of ending global hunger by 2030 is slipping out of reach due to conflict, climate change and other factors.
Mars lander: NASA's Mars InSight lander became the first spacecraft to successfully land on Mars since 2012 when it touched down on Nov. 27. It's mission: to drill deep into Mars' interior and explore how the planet formed.
The insect apocalypse: Brooke Jarvis writes for the New York Times Magazine about the global decline in insects and what it might mean for human culture, natural systems and survival.
Open water: The Inuit are seeking more control over a vast opening in the sea ice between Greenland and Canada’s Ellesmere Island that typically forms each year, writes Julia Rosen for Hakai Magazine.
Moon landers: NASA is partnering with 9 companies to send small robotic landers to the moon, the agency announced today. The landers are "a first phase in a multiyear plan to put humans on the lunar surface again," reports Loren Grush for The Verge.
A baby blue whale nursing captured off the South Coast of Sri Lanka in 2015. Photo: Patrick Dykstra/Barcroft Images/Barcroft Media via Getty Images
Blue whales are changing their tune, according to a new study published in the Journal of Geophysical Research: Oceans.
Why it matters: The global decline in the pitch of whale songs has been a mystery, with chief suspects being the increase in ocean noise from shipping, submarines and underwater resource exploration. The new study, however, suggests other factors may be behind the trend.
Details: The researchers found that a seasonal variation to Antarctic blue whales' pitch correlates with breaking sea ice in the southern Indian Ocean, suggesting that seasonally they're laboring to make their voices heard above the crackling and grinding sounds of breaking ice.
What they did: The paper analyzed more than 1 million songs from three species of large baleen whales: fin, Antarctic blue and three acoustically distinct populations of pygmy blue whales.
What they found: Between 2002 and 2015, the pitch of blue whales' calls had fallen by "about a whole tone or major second interval in Western music tradition," the press release states.
This trend is intriguing, but has not yet had major consequences.
“They can decrease their call intensity to keep in touch, because there are more whales," Emmanuelle Leroy, lead author of the new study and a research fellow at the University of New South Wales in Australia, said in a press release. "These calls are long distance communication.”
Thanks so much for reading! See you next Thursday.