420.13 ppm: tracking regular climate news

Welcome to our regular segment on new climate news stories you might have missed. The title refers to the daily average global concentration of carbon dioxide within the Earth’s atmosphere in parts per million (ppm). Meaning that for every million air particles, currently about 420.13 of them are CO₂.

We’re keeping all eyes on the Intergovernmental Panel on Climate Change, who will be releasing the next part of their sixth assessment report on Monday – but for now, here’s five smaller climate studies.

Ozone heating the Southern Ocean

Ozone’s a tricky gas, providing key protection at one point in the atmosphere and damaging heating in another.

A paper in Nature Climate Change states that ozone levels have been responsible for nearly a third of warming in the Southern Ocean from 1955 to 2000.

 “Ozone close to Earth’s surface is harmful to people and the environment, but this study reveals it also has a big impact on the ocean’s ability to absorb excess heat from the atmosphere,” says Associate Professor Michaela Hegglin, a researcher in atmospheric chemistry at the University of Reading, UK.

“These findings are an eye-opener and hammer home the importance of regulating air pollution to prevent increased ozone levels and global temperatures rising further still.”

Storm surges on the rise

There’s ongoing debate around whether storm surges are increasing with climate change. US and UK researchers have affirmed the theory, with evidence that storm surges have been on the rise in Europe since 1960.

They have also found that this rise in storm surges matches mean sea level rise over the same time period. Their statistical analysis is published in Nature.

“Our results are contrary to the current planning practice of assuming stationary storm surge extremes, and show that anthropogenic forcing might have already altered the likelihood of such extremes,” write the authors in their paper.

Methane leaks are worse than their estimates

The actual amount of methane being leaked from oil and gas producers in New Mexico, US, is much higher than estimates from the country’s Environment Protection Agency, according to a study in Environmental Science & Technology.

The researchers used airborne sensors to detect methane from individual oil and gas facilities.

“We surveyed almost every oil and gas asset in the New Mexico Permian for an entire year to measure and link emissions to specific anonymised facilities,” says co-author Evan Sherwin, a post-doctoral researcher at Stanford University, US.

“It’s worse than we thought by a long shot.”

But the researchers are optimistic: they found their methane sensing technique was very effective, and once a leak has been spotted, they point out that addressing it is usually straightforward.

Relying on Southeast Asia to step up its rice production

The world’s demand for rice is set to increase by 30% by 2050. Some major rice producers – including China and India – are already at production capacity, but there’s space for southeast Asian countries to step up their productivity.

But, according to an analysis in Nature Food, this step-up in production is at risk from climate change – among other related threats.

“Over the past decades, through renewed efforts, countries in southeast Asia were able to increase rice yields, and the region as a whole has continued to produce a large amount of rice that exceeded regional demand, allowing a rice surplus to be exported to other countries,” says lead author Dr Shen Yuan, a postdoctoral research associate at Huazhong Agricultural University, China.

“The issue is whether the region will be able to retain its title as a major global rice supplier in the context of increasing global and regional rice demand, yield stagnation and limited room for cropland expansion.”

AI to predict bushfire cost

A team of US researchers have developed a machine learning tool for predicting socioeconomic risks from bushfires.

Publishing their findings in Nature Communications, the researchers say that their model shows that more populations will be exposed to fires over the next century, increasing socioeconomic risk. They also found that the carbon dioxide emitted by fires would increase, but at a lower level than current fire output.

They say that, while their machine learning approach has limitations, it can now be used to predict risk on more local scales as well.