industrial activities

The Amazon rainforest is the largest rainforest in the world, covering more than 2.5 million square miles. More than three million species live in the rainforest, which constitutes approximately 10% of the world’s known biodiversity. The Amazon rainforest’s biodiversity is so rich that scientists are still discovering new species all the time.

The Amazon rainforest absorbs huge amounts of carbon dioxide from Earth’s atmosphere, making it a key part of mitigating climate change. But the amount of carbon dioxide absorbed by the Amazon rainforest today is 30% less than it was in the 1990s.

Deforestation of the Amazon rainforest remains a major problem. Cattle ranching is the leading cause of deforestation, but industrial activities, such as the mining of oil and gas, copper, iron, and gold, are also to blame.

According to a new study recently published in the journal Nature, global warming may be interacting with regional rainfall and deforestation to accelerate forest loss in the Amazon. In fact, it may be pushing the rainforest towards a partial or total collapse.

The study, which was led by researchers from Federal University of Santa Catarina in Brazil and the University of Birmingham in the U.K., has identified the potential thresholds of these stressors, and highlighted how their combined effects could produce a tipping point for the Amazon rainforest.

The findings are important because the Amazon rainforest plays a vital role in the global climate system. By identifying the most important stressors on the rainforest environment, the researchers hope they can develop a plan to keep the Amazon rainforest resilient.

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Is the Amazon forest approaching a tipping point?

Photo, posted July 2, 2017, courtesy of Anna & Michal via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

The early months of the COVID-19 pandemic saw drastic reductions in travel and other economic sectors across the globe that greatly decreased air pollution and greenhouse gas emissions. These dramatic changes occurred quite suddenly. This abrupt set of changes gave scientists the unprecedented opportunity to observe the results of changes that would ordinarily have taken years if they came about through regulations and gradual behavior shifts.

A comprehensive study by Caltech on the effects of the pandemic on the atmosphere has revealed some surprising results.

The biggest surprise is that even though carbon dioxide emissions fell by 5.4% in 2020, the amount of CO2 in the atmosphere continued to grow at about the same rate as in previous years. According to the researchers, the reasons are that the growth in atmospheric concentrations was within the normal range of year-to-year variations caused by natural processes and, in addition, the ocean did not absorb as much CO2 because of the reduced pressure of CO2 in the air at the ocean’s surface.

A second result involved the reduction in nitrogen oxides, which led to a reduction in a short-lived molecule called the hydroxyl radical, which is important in breaking down gases including methane in the atmosphere. Reducing nitrogen oxides is advantageous with respect to air pollution, but they are important for the atmosphere’s ability to cleanse itself of methane. In fact, the drop in nitrogen oxide emissions actually resulted in a small increase of methane in the atmosphere because it was staying there longer.

The main lesson learned is that reducing activity in industrial and residential sectors is not a practical solution for cutting emissions. The transition to low-carbon-emitting technology will be necessary.

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Emission Reductions From Pandemic Had Unexpected Effects on Atmosphere

Photo, posted March 22, 2020, courtesy of Greg via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Is the Amazon rainforest nearing a tipping point?

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Emissions And The Pandemic | Earth Wise

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