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Forest Regrowth In The Amazon | Earth Wise

January 20, 2020 By EarthWise Leave a Comment

The Amazon is the largest tropical rainforest in the world. It covers an area approximately equal in size to the lower 48 states, and is home to an estimated 10% of the world’s biodiversity and 15% of its freshwater. These so-called “lungs of the planet” provide many important global ecological services, including carbon storage, and regulating air quality and climate.

Deforestation in the Amazon exploded in the 1970s and remains one of its biggest threats today. Since the 1970s, more than 20% of the Amazon rainforest has been cleared. Cattle ranching, soy and palm plantations, logging, and climate change are some of the biggest drivers of deforestation.

Now, according to a new study recently published in the journal Ecology, the regrowth of Amazonian forests following deforestation may happen more slowly than previously thought. These findings could have significant impacts on climate change predictions as the ability of forest regrowth in the Amazon – so-called secondary forests – may have been overestimated. The research, which was conducted in Bragança, Brazil and includes two decades of forest monitoring, reveals that climate change and the wider loss of forests could be hampering regrowth.

After 60 years of regrowth, the research team found that secondary forests only held 40% of the carbon when compared with forests undisturbed by humans. Secondary forests also take less carbon from the atmosphere during periods of drought, and climate change is increasing the number of drought-years in the Amazon. (During their 20 years of monitoring, the researchers also found biodiversity levels in secondary forests were only 56% of those seen in undisturbed forests).

More long-term studies are needed to better understand the impacts of reforestation efforts.

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Amazon forest regrowth much slower than previously thought

Photo, posted September 6, 2009, courtesy of Nao Lizuka via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Mistaking Plastic For Food

September 27, 2019 By EarthWise Leave a Comment

Green sea turtles are one of the world’s largest species of turtle, with some measuring close to four feet long and weighing up to nearly 300 pounds. Their range extends throughout tropical and subtropical seas around the world, with the largest nesting populations found in Costa Rica and Australia.

Green sea turtles get their name from the green layer of fat under their shell, as opposed to their shell itself, which can be brown, green, yellow, and/or black. Scientists believe the green coloring of their fat is a result of their diet. Unlike most other sea turtles, green sea turtles eat marine plants such as seaweed and seagrass.

But new research suggests that green sea turtles are also more likely to swallow plastic because it resembles their natural diet. The scientists from the University of Exeter and the Society for the Protection of Turtles who examined green sea turtles that washed up on beaches in Cyprus found they favored narrow lengths of plastic in natural colors (like green and black) as opposed to debris of other shapes and colors.

Researchers were able to examine the full gastrointestinal tract of 19 green sea turtles. They found pieces of plastic inside every one of them, with the number of pieces ranging from three to 183. Smaller turtles tended to contain more plastic, possibly because they are less experienced or because diet choices change with age and size.

Previous research has suggested that leatherback sea turtles also eat plastic that resembles their food: jellyfish.

Researchers hope these findings will help motivate us to continue to work on reducing our overall plastic consumption and pollution.

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Green turtles eat plastic that looks like their food

Photo, posted September, 2007, courtesy of Brock Roseberry via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Climate Change And Economic Inequality

June 3, 2019 By EarthWise 1 Comment

A new study by Stanford University looked at the effects of climate change on global economic inequality. The study found that the gap between the economic output of the world’s richest and poorest countries is larger today than it would have been without global warming.

The warming climate has enriched cooler countries like Norway and Sweden while dragging down economic growth in warm countries such as India and Nigeria. The results of the study showed that most of the poorest countries on Earth are considerably poorer than they would have been in the absence of rising temperatures. At the same time, the majority of rich countries are richer than they would have otherwise been.

Detailed analysis of 50 years of annual temperature and GDP measurements for 165 countries demonstrated that growth during warmer than average years has accelerated in cool nations and slowed in warm nations. Historical data clearly show that crops are more productive, people are healthier, and they are more productive at work when temperatures are neither too hot nor too cold. That means that in cold countries, a little bit of warming can help but the opposite is true in places that are already hot.

For most counties, whether global warming has helped or hurt economic growth is pretty certain. Tropical countries in particular tend to have temperatures far outside the ideal for economic growth and they are already among the poorest countries. It is less clear how warming has influenced growth in countries in the middle latitudes, such as here in the United States. Some of the largest economies are near the perfect temperature for economic output but continued warming in the future is likely to push them away from the temperature optimum.

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Climate change has worsened global economic inequality

Photo, posted November 1, 2011, courtesy of CIAT via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Another Problem For Coral Reefs

April 5, 2019 By EarthWise Leave a Comment

Coral reefs around the world have been suffering in recent years from warming ocean temperatures as well as from increasing ocean acidification. Corals are very sensitive organisms that can only tolerate relatively slight changes in their environment. Thus, the majority of reef-building corals are found in tropical and subtropical waters with favorable conditions.

New research has confirmed that drastic changes in ocean salinity from, for example, severe freshwater flooding, provoke similar stress responses in corals as the heating that has resulted in freshwater bleaching and, eventually, coral death.

The coast of northeast Queensland in Australia has experienced abnormal monsoon-related freshwater flooding that caused extreme and sudden changes in the ocean salt concentration. In places, nearshore reefs were exposed to water with only half the normal ocean salinity. The result has been a shock response in corals that prevents normal cell function. Unlike their response to heat stress, corals exposed to reduced salinity experience a complete collapse of their internal cellular protein balance.

The central Great Barrier Reef has actually been relatively free from mass thermal bleaching events this Australian summer, but many coastal reefs instead have been battling dramatic changes in water conditions as a result of massive plumes of floodwater.

The wild weather in Australia is undoubtedly associated with the changing climate and this new research shows that it is leading to yet another threat to the world’s coral reefs. With the frequency and severity of heavy rainfall and runoff events predicted to continue to increase over the next few decades, proactive measures to increase the resiliency of coral reefs are needed more than ever.

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Reduced salinity of seawater wreaks havoc on coral chemistry

Photo, posted December 12, 2010, courtesy of Gareth Williams via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Deforestation-Free Palm Oil

July 10, 2018 By EarthWise Leave a Comment

Few of us cook with palm oil or have ever even seen the stuff. Nevertheless, 50% of all packaged grocery items – everything from ice cream and pizza to detergents and cosmetics – include it as an ingredient. The global market for palm oil was $65 billion in 2015, and that number was projected to grow by more than 7% each year through 2021.

Indonesian Deforestation Continues

May 3, 2018 By EarthWise Leave a Comment

Worldwide, deforestation and land disturbance are responsible for about a quarter of all greenhouse gas emissions. The largest contributor to this problem is Indonesia and getting control of its emissions is a crucial part of meeting global carbon reduction targets.

The State Of The Birds

June 6, 2016 By WAMC WEB

The North American Bird Conservation Initiative recently released its annual “State of the Birds’ report, which is a comprehensive analysis of North American birds. And as with many other things these days, we’re not doing well.

Primates And Toucans As Climate Allies

January 14, 2016 By WAMC WEB

Many of us have a soft spot for primates and toucans. These charismatic creatures are prized for their intellect and beauty. But did you know they also play a vital role in combating climate change?