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Approaching critical global temperature thresholds

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The Paris Climate Agreement is a global treaty adopted in 2015 to combat climate change by limiting global warming to well below 2°C above pre-industrial levels, while striving to keep it below 1.5°C.  But according to recent research, the planet is quickly approaching these critical thresholds. 

An international research team led by scientists from Colorado State University, Stanford University, and ETH-Zurich in Switzerland combined insights from 10 global climate models, and – with the help of artificial intelligence – found that regional warming thresholds are likely to be reached faster than previously thought.

In fact, the researchers found that most land regions will likely surpass the critical 1.5°C threshold by 2040 or even earlier.  Additionally, several regions are on track to exceed the 3.0°C threshold by 2060.  Regions including Central Europe, the Mediterranean, South Asia, and parts of sub-Saharan Africa are expected to reach these thresholds faster. 

The research team relied on transfer learning, a cutting-edge machine learning technique that leverages pre-trained models to tackle new, related tasks.

The research, which was recently published in the journal Environmental Research Letters, found that 34 regions are likely to exceed 1.5°C of warming by 2040.  Of those 34 regions, 31 of them are expected to reach 2°C of warming by 2040, and 26 of these 34 regions are projected to surpass 3°C of warming by 2060.

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AI predicts that most of the world will see temperatures rise to 3C much faster than previously expected

Photo, posted February 23, 2011, courtesy of 2011 CIAT / Neil Palmer via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

City Greenery And Carbon Emissions | Earth Wise

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According to the United Nations, more than half of the world’s population currently lives in cities.  Projections show that the combination of urbanization and global population growth could add another 2.5 billion people to cities by 2050. 

Unsurprisingly, cities are a major contributor to climate change.  According to U.N. estimates, cities are responsible for 75% of global carbon dioxide emissions, with transportation and buildings being among the largest contributors. 

According to a new study of vegetation across New York City and some adjoining urban areas, photosynthesis by trees and grasses on many summer days absorbs all the carbon emissions produced by cars, trucks and buses, and then some.  In fact, on many summer days, the total carbon uptake in the region equaled up to 40% of a summer afternoon’s total emissions from all sources in the City. The results, which were recently published in the journal Environmental Research Letters, further highlights the critical importance of urban greenery.

Most previous studies have analyzed the carbon uptake of vegetation by looking at the contiguous tracts of green spaces, but this only comprises about 10% of metro areas.  Using detailed aerial radar imagery of New York City that mapped vegetation in unprecedented 6-inch grids, the researchers were able to include the other 90% of the metro area typically left out in most models. 

Since carbon uptake by vegetation only occurs during the growing season, green spaces in cities situated in warmer climates likely play a larger role in carbon uptake. 

As city populations swell around the world, every bit of urban greenery is critical in the fight against climate change. 

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New York City’s greenery absorbs a surprising amount of its carbon emissions

68% of the world population projected to live in urban areas by 2050, says UN

Photo, posted October 5, 2009, courtesy of David Orban via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Drugs In The Water

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According to a new study published in the journal Environmental Research Letters, concentrations of pharmaceuticals in rivers and lakes have dramatically increased across the globe over the past 20 years.

Traces of medicines get passed into waterways through the excretion of active drugs in human waste, the disposal of unused medicines down drains, and runoff from livestock farms.

The study looked in detail at two specific drugs:   carbamazepine, an anti-epileptic drug, and ciprofloxacin, an antibiotic.   The study found that the risk of ecological damage from the residue from these two drugs was 10 to 20 times higher in 2015 than in 1995.

Chronic exposure to carbamazepine, for example, has been shown to alter feeding behavior and reduce egg viability in zebrafish, as well as reduce reproductive success in crustaceans.  Antibiotics can alter major nutrient cycles and decrease the effectiveness of bacteria-based wastewater treatment systems.

The study, led by researchers from the Netherlands, created a new model estimating concentrations of the two drugs over a 20-year period in 449 aquatic systems around the globe.  The model predicts a relatively high environmental risk in densely populated and dry areas such as the Middle East. 

When the researchers compared the model’s results to samples from four river systems in various locations, they found that the actual drug concentrations were even higher than model results, in some cases by a factor of 10 to 100. 

The new model should act as a guide for a more thorough investigation into pharmaceutical residues in waterways, which pose significant environmental risks all over the world.

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Concentrations of Pharmaceuticals in Freshwater Increasingly Globally

Photo, posted March 22, 2012, courtesy of Rajeev Rajagopalan via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Indonesian Deforestation

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Deforestation is defined as the intentional destruction of trees and other vegetation without reforesting or allowing the forest to regenerate itself. 

In Indonesia, industrial agriculture, primarily for the production of palm oil, is a major driver of deforestation.  But, according to researchers at Duke University, its impact has diminished  proportionately in recent years as other natural and human causes have emerged. Their peer-reviewed findings were recently published in the journal Environmental Research Letters.

According to the study’s lead author, large-scale plantations were responsible for more than half of Indonesia’s deforestation in the late 2000s, peaking between 2008-2010 when an average of 1.5 million acres of forest was lost annually.  The expansion of the massive plantations was responsible for 57% of the forest loss. Between 2014-2016, an average of more than 2 million acres of forest was lost annually, but plantation expansion only accounted for 25% of this figure.  While the overall rate of deforestation continued to grow, other factors were responsible for most of it.

Conversions of forests to grasslands rose sharply in 2015 and 2016 when El Nino caused severe droughts and forest fires. Small-scale farming, often overshadowed by industrial agriculture, was also found to play a bigger role, accounting for 25% of all forest loss. 

Indonesia has experienced some of the highest rates of deforestation.  Its forests absorb and store vast amounts of climate-warming carbon dioxide, help prevent erosion and flooding, and provide habitat to thousands of species.  Understanding the varied causes of Indonesian deforestation should help conservationists and policymakers better address the problem.

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Palm oil not the only driver of forest loss in Indonesia

Photo, posted March 26, 2018, courtesy of Achmad Rabin Taim via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

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