418.49 ppm: tracking weekly climate news

Welcome to our regular segment on new climate news stories you might have missed. The title refers to the average global concentration of carbon dioxide within the Earth’s atmosphere in parts per million (ppm). Meaning that for every million air particles, currently 418.49 of them are CO₂.

Thawing permafrost could expose Arctic populations to cancer-causing radon

Climate change-induced thawing of permafrost could expose Arctic populations to much greater concentrations of the lung cancer-causing, radioactive gas radon. New research has found that permafrost acts as a protective barrier which significantly reduces the amount of radon travelling to the surface and entering buildings to a 10th of the background level.

By modelling radon production, its flow through the soil, and permafrost thawing, researchers showed that in buildings with basements, the presence of radon gas can increase to more than a 100-times its initial value for up to seven years, depending on the depth of the permafrost and how fast it thaws.

No such increase was found for traditionally constructed buildings, which are built on piles in the Arctic community. The research was published in Earth’s Future.

“If the permafrost were stable, there would be no cause to be concerned,” says author Paul Glover, professor in the School of Earth and Environment at the University of Leeds, UK.

“However, it is now widely recognised that climate change is leading to significant thawing of permafrost, with a 42% expected loss of permafrost in the Arctic Circumpolar Permafrost Region (ACPR) by 2050,” he says.

“Since there has been no perceived historical radon problem in these communities, and the gas itself is undetectable without specialist devices, we regard this as an important and totally avoidable threat to the health of the northern communities.

“Fortunately, simply installed ventilation is all that is often required if the problem is recognised.”

Human-induced climate change impacts Mount Everest

Mount Everest’s highest glacier is rapidly retreating due to human-induced climate change, with new research finding that several decades of glacial accumulation is being lost annually through melting and sublimation (changing from a solid to vapour state).

An international team of researchers analysed data from the world’s highest-ever ice core, and the two highest weather stations. They found that approximately 55 metres of glacier thinning is estimated to have occurred in a quarter of a century – occurring over 80 times faster than the nearly 2,000 years it took to form.

Published in npj Climate and Atmospheric Science, the study indicates that the glacier has turned from snowpack to ice (losing its ability to reflect solar radiation), and estimate that it will continue to thin at rates of about two metres per year.

This latest research confirms that human-sourced climate change reaches even high-mountain glaciers, and forewarns of emerging impacts which range from increased incidences of avalanches to decreased capacity of high-altitude Himalayan ice masses to store water (more than 1 billion people depend on melt water for drinking water and irrigation).

Switching inhalers could help cut the carbon footprint of your asthma

Classic “puffer” style inhalers use hydrofluorocarbons (HFCs), which are potent greenhouse gasses, and their emissions account for 3-4% of the total carbon footprint of healthcare in the UK. New research has found that switching from a pressurised metered-dose inhaler (pMDI) to a dry powder version – in which medicine is held as a dry powder and is delivered to the lungs by breathing in fast and deep – more than halves their asthma-associated carbon footprint.

Scientists carried out a secondary analysis on data from a previous study in which a group of 4,000 patients with asthma were either assigned to continue using a metered-dose inhaler, or switch to using a dry powder inhaler. They also found that asthma control was consistently better over the 12 months of the study for patients who switched to a dry powder inhaler than those who continued with their normal asthma care.

The researchers conclude that their results support the growing calls from official bodies that, where possible, switches from pMDI to low carbon-impact alternatives should be sought.

The study was published in The BMJ.

Massive methane emissions by oil and gas industry detected from space

Methane (CH₄) is a major contributor to climate change, with a global warming potential about 30 times greater than CO₂ over a 100-year period. One-third of all human-caused methane emissions originate from the extraction of coal, oil and natural gas (of which methane is the main component).

Actual emissions from oil and gas extraction and distribution activities had previously been underestimated due to undeclared sporadic releases of large quantities by industry operators. Now, an international study has uncovered hundreds of major methane releases linked to global oil and gas extraction activities.

Published in Science, researchers analysed thousands of daily images generated by the European Space Agency’s Sentinel-5P satellite from 2019-2020 and mapped 1,800 methane plumes – of which 1,200 were attributed to fossil fuel extraction. These massive releases always appeared over the largest oil and gas basins throughout the world.

By considering the underlying social costs related to climate change and air quality, as well as the monetary cost of the gas wasted, the study suggests that limiting these emissions would yield billions of dollars in net savings for the six major oil and gas producing countries.

We’ve underestimated the greenhouse gas emissions impact from peatland fires

Deforestation fires are hindering climate change mitigation efforts and compounding global environmental challenges. According to new research, deforestation fires in Brazil and Indonesia accounted for 3% and 7%, respectively, of global greenhouse gas (GHG) emissions in 2019 and 2020.

Many of these fires burned in carbon-rich peatlands – a type of wetland which occur across 180 countries and store twice as much carbon as any other vegetation type.

Published in Frontiers, the researchers used publicly available data for deforestation in Brazil and Indonesia to estimate the total GHG impact of the peatland fires in 2019 and 2020, and compared this with previous GHG estimates to show that prior data underestimated the true impact of deforestation fires during severe fire years.

“Monitoring and measurement challenges in peatlands lead to an underestimation of the true impact of deforestation fires,” says author Dr Ramanan Krishnamoorti, of the University of Houston in the US.

“Since these estimates form the basis of the policy response from national governments, it results in inadequate attention to forest and peatland protection as part of climate crisis mitigation efforts.”