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An aerial view of deforestation in the Amazon basin forest of Brazil.

Deforestation in Altamira, Pará state, Brazil.Credit: Joao Laet/AFP via Getty

Averting the Amazon’s point of no return

Climate change, deforestation and fires could cause the world’s largest rainforest to hit a tipping point that could turn much of it into dry scrubland. There would be an impact on biodiversity, livelihoods, carbon emissions and weather patterns. Scientists are desperately exploring just how big the effects might be, when the tipping point could occur — and what must be done to stop it.

Nature | 11 min read

Forest loss. Map showing deforestation in Amazonia.

Sources: TerraBrasilis (Brazil data 1988–2007); RAISG (other countries data and Indigenous territories/Amazonia borders); Hansen/UMD/Google/USGS/NASA (tree-loss data 2000–18: https://go.nature.com/39CE2FC); ESA Land Cover CCI Product (forest cover).

Pauling’s chemistry rules ‘more like guidelines’

Nobel laureate Linus Pauling’s ‘rules’ that describe the preferred crystal structures adopted by ionic compounds are more like loose guidelines. Chemists tested the five rules against 5,000 oxide structures and found that just 13% satisfied four of the five rules. “These rules, despite being taught in every chemistry textbook, have a much lower predictive power than one would think,” says chemist Geoffroy Hautier.

Chemistry World | 4 min read

COVID-19 coronavirus outbreak

A prevention tent for coronavirus patients was built in front of the emergency room of the hospital in Turin, Italy.

A hospital in Turin, Italy; hundreds of cases of COVID-19 have emerged in the country.Credit: Mauro Ujetto/NurPhoto via Getty

What we need to know to tackle a pandemic

• Coronavirus outbreaks in South Korea, Italy and Iran — which include cases with no clear link to China, as well as signs that some went undetected for weeks — are prompting scientists to consider whether COVID-19 might soon become pandemic. If the virus’s spread becomes widely uncontained, we might soon move from current strategies — identifying and isolating infected people — to a ‘social distancing’ approach that doesn’t depend on knowing who’s infectious. Pandemic or not, many important questions remain unanswered — such as how coronavirus spreads between children and to what extent survivors become immune. (Nature | 6 min read)

• The administration of US president Donald Trump has requested that Congress earmark up to $2.5 billion to fund the country’s response to COVID-19. Of that, $1.25 billion would come from new funding; the rest would be repurposed funds originally allocated to other programmes, including $535 million assigned to the Ebola response. The amount is far below what was allocated to past outbreaks such as H1N1, and critics have called it overdue and insufficient. (The New York Times | 7 min read)

Read the latest coronavirus news, continuously updated on Nature.

Notable quotable

“Often, nurses’ mouths are covered in blisters. Some nurses have fainted due to hypoglycaemia and hypoxia. In addition to the physical exhaustion, we are also suffering psychologically. While we are professional nurses, we are also human.”

Nurses in Wuhan, China, face intense stress from constantly wearing protective equipment and facing the risk of being infected themselves, write nurses Yingchun Zeng and Yan Zhen. They ask for help from the international medical community in a heart-rending letter in The Lancet.

Features & opinion

How to write a top-notch paper: peer review

In this four-part podcast series about writing a paper, scientists share the highs and lows of getting published for the first time, and what the experience taught them. In the second episode, four researchers and a manuscript editor explain the best way to respond when your paper is rejected or receives peer-review comments that you disagree with.

Nature | 15 min listen

Butterflies offer lessons in resilience

Environmental researchers Sheila Colla, Dana Prieto and Lisa Myers touch on art, history and science as they explore what pollinator declines have to do with a wave of protests that has swept across Canada. Demonstrators stand in solidarity with Wet'suwet'en hereditary chiefs, who object to a proposed natural-gas pipeline project in their traditional territory.

The Conversation | 5 min read

Quote of the day

“Earth has a new temporarily captured object /Possible mini-moon.”

Astronomer Kacper Wierzchos spotted an asteroid temporarily orbiting Earth, which was captured by the planet’s gravity around three years ago. (CNET)