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Elephants And Global Warming | Earth Wise

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A study by researchers at Saint Louis University has found that elephants play a key role in creating forests that store large amounts of atmospheric carbon and in maintaining the biodiversity of forests in Africa.  Since elephants are endangered, their status represents a significant threat to an ecosystem that is very important to the Earth’s climate.

The African rainforest contains trees with both low carbon density (light wood) and high carbon density (heavy wood).  High carbon density trees grow more slowly and can be crowded out by the faster growing low carbon density trees rising above them.  Elephants affect the relative abundance of these trees by feeding more on the low carbon density trees which are more palatable and nutritious.  This thinning of the forest allows the trees that sequester the most carbon to flourish.

Elephants are also excellent dispersers of the seeds of high carbon density trees.  Essentially, elephants are the gardeners of the forest.  They plant the forest with high carbon density trees and get rid of the weeds – in this case, the low carbon density trees.  According to the study, if elephants were to become extinct, the African rainforest – the second largest on earth – would gradually lose between six and nine percent of its ability to capture atmospheric carbon.

Elephants have been hunted by humans for millennia.   Gaining support for protecting them has mostly been driven by the argument that everybody loves elephants.  Focusing on their role in maintaining forest diversity has not driven much more action.  The hope is that the evidence of how important elephants are for climate mitigation will be taken seriously by policy makers to generate the support needed for improved elephant conservation.

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Can Elephants Save the Planet?

Photo, posted March 15, 2008, courtesy of Michelle Gadd/USFWS via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Large Mammals And Climate Change | Earth Wise         

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The natural world has an important part to play in mitigating the effects of climate change.  We mostly think about the role of plant life which absorbs carbon in trees, grasses, and other flora.  However, a new study published by Oxford University looks at the role of large wild animals in restoring ecosystems and reducing the effects of climate change.

According to the study, there are three important ways in which large animals such as elephants, rhinos, giraffes, whales, bison, and moose can potentially mitigate the effects of climate change:  carbon stocks, albedo, and fire regimes.

When large herbivores graze, they disperse seeds, clear vegetation, and fertilize soil.  All of these things build more complex and resilient ecosystems which helps to maintain and increase carbon stocks in the soil and in plant tissues thereby helping to reduce CO2 in the atmosphere.

Grazing large animals trample vegetation which opens up areas of dense vegetation to create open mixes of grass and shrubs and can reveal snow-covered ground in cold regions.  Such open habitats are lighter in color (higher in albedo) and reflect more solar radiation into the atmosphere, cooling the Earth’s surface rather than heating it up.

Large grazing animals can lessen wildfire risk by browsing on woody vegetation that would otherwise fuel the fires and also by creating paths that act as firebreaks.

In marine ecosystems, whales and other large animals fertilize phytoplankton, which capture some 37 billion tons of CO2 each year.

Overall, large animals are an important part of the natural world’s ability to reduce the effects of the changing climate by helping with localized adaptation to the changes taking place in ecosystems.

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Large mammals can help climate change mitigation and adaptation

Photo, posted August 20, 2017, courtesy of Jon Niola via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Keeping Venice From Flooding | Earth Wise

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Since 2003, Venice Italy has been building a system of mobile gates at three inlets to its famous lagoon.  The project is called MOSE, the Italian word for Moses, but is actually an acronym for the Italian words meaning Experimental Electromechanical Module.  

The 78 mobile gates are metal box structures that sit at the bottom of inlet channels.  When a high tide is predicted, compressed air is pumped into the structures.  The air causes the barriers to rise up to the surface and block the flow of the tide, thereby preventing water from flowing into the lagoon.

The system had an important test on November 3 when water levels were predicted to rise four-and-a-half feet above normal at high tide and strong winds were blowing.  Water at that level is enough to flood 60% of the city, including the famous St. Mark’s Square, which is unfortunately the lowest part of the city.

Activating the flood gates proved to be successful.  Even though high tide water levels in fact rose 4.3 feet in the surrounding Adriatic Sea, they only reached 2.7 feet in Venice, which was enough to prevent significant flooding.

Rising sea levels have led to increasingly frequent floods in Venice.  In 2019, before the MOSE system was available for use, there were more than 25 high-water events swamping Venice, including one in November of that year that was the second worst on record.

Some researchers have calculated that the system will need to be closed for as much as 3 weeks a year by the end of the century even if emission reductions are reasonably effective.  If they aren’t, the gates may be closed for at least two months a year by 2080.

After many years of delays, setbacks and controversies, the system is finally operational.

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Venice Holds Back the Adriatic Sea

Photo, posted October 25, 2014, courtesy of Pedro Szekely via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Global Flood Risk From Melting Ice | Earth Wise

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Approximately 10% of the land area on Earth is covered by ice.  This includes glaciers, ice caps, and the ice sheets of Antarctica and Greenland.  Nearly 70% of all fresh water on earth is locked away in ice.  If all this land ice were to melt, global sea levels would rise by more than 200 feet. 

According to new research led by researchers at the University of Leeds in the U.K., global warming is causing extreme ice melting events in Greenland to become more frequent and more intense over the past 40 years, leading to an increased risk of flooding worldwide.   

According to the findings, which were recently published in the journal Nature Communications, approximately 3.85 trillion tons of ice has melted from the surface of Greenland and into the ocean during the past decade alone.  That’s enough melted ice to cover all of New York City with nearly 15,000 feet of water. 

Rising sea levels threaten the lives and livelihoods of those living in coastal communities around the world.  Beyond the obvious risk of flooding in low-lying areas, rising seas also disrupt marine ecosystems that many coastal communities rely on for food and work.       

Rising sea levels can also alter patterns of ocean and atmospheric circulation, which in turn affect weather conditions around the planet.

Estimates from models suggest that melting ice from Greenland will contribute between 1 inch and 9 inches to global sea level rise by 2100. 

These findings are just another reminder of how we need to act urgently to mitigate climate change if we want to prevent the worst-case scenarios from becoming reality. 

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Increased frequency of extreme ice melting in Greenland raises global flood risk

Photo, posted April 21, 2017, courtesy of Markus Trienke via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Russian Forests And Climate Mitigation | Earth Wise

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Russia is the largest country in area in the world, almost equal in size to the sum of the next two largest – Canada and the U.S.   Russia is also the world’s largest forest country, containing more than one-fifth of the world’s forests.  As a result, the country’s forests and forestry activities have enormous potential for impacting climate mitigation.

Since the dissolution of the USSR, there has been a decline in the availability of information on the state of Russia’s forests.  The Soviet Forest Inventory and Planning System compiled information until 1988.  Since then, the Russian National Forest Inventory has been the source of forest information on the national scale, and it hadn’t produced a comprehensive inventory until 2020.

The new data indicates that Russian forests have in fact accumulated a large amount of additional biomass over the intervening years.  Using the last Soviet Union report as a reference point, the new results show that the ongoing stock accumulation rate in Russian forests over the 26-year period is of the same magnitude as the net forest stock losses in tropical countries.

Thus, it is clear that Russian forests have great potential in terms of global climate mitigation as well as potential co-benefits relating to the green economy and sustainable development.   It is important to note that as the impact of climate change increases, disturbances to the Russian forests could have severe adverse effects on global climate mitigation efforts.

While much of the world’s attention is rightfully upon tropical rainforests in the Amazon and elsewhere, it is important to not ignore the largest country in the world hosting the largest land biome on the planet where even small percentage changes in the amount of forest biomass could have a major global impact.

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Russian forests are crucial to global climate mitigation

Photo, posted June 6, 2015, courtesy of Raita Futo via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Protecting The Ocean Has Multiple Benefits | Earth Wise

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An international team of authors from 18 institutions has recently published a paper in the journal Nature that offers a solution that addresses several of humanity’s most pressing problems at the same time.  The paper provides a comprehensive assessment of where strict ocean protection can contribute to a more abundant supply of healthy seafood, help address climate change, and protect embattled species and habitats.

The study identified specific areas of the ocean that could provide all of these benefits if they were protected.  Currently, only about 7% of the ocean is under any kind of protection.  According to the study, if the appropriate 30% of the ocean was protected by the actions of the relevant countries by 2030, the cited benefits would be realized.

Safeguarding these regions would protect nearly 80% of marine species while increasing fishing catches by almost 9 million tons a year. It would also prevent the release of more than 1 billion tons of carbon dioxide by protecting the seafloor from bottom trawling, which is a widespread and destructive fishing practice.

Ocean life has been declining worldwide because of overfishing, habitat destruction, and climate change.  The study pioneers a new way to identify the places that – if protected – will boost food production and safeguard marine life, while at the same time reducing carbon emissions.  The study finds that countries with large national waters and large industrial trawl fisheries have the highest potential to contribute to climate change mitigation by protecting the carbon stored on the ocean floor.  The ocean covers 70% of the Earth and its importance in solving the challenges of our time must not be underestimated.

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Three Times the Gains

Photo, posted January 10, 2016, courtesy of Hafsteinn Robertsson via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Seagrasses And Ocean Acidification | Earth Wise

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Seagrasses are the basis of important marine ecosystems.   Sea turtles, bat rays, leopard sharks, fish, and harbor seals are just some of the marine creatures that visit seagrass ecosystems for the food and habitat they provide.  They are nursery grounds for many aquatic animals and many birds visit seagrass meadows to dine on what lives within them.  They may seem like slimy grasses that we walk through along some shorelines, but they are important.

These marine forests are valuable for many different reasons including climate mitigation and erosion control.  A third of the carbon dioxide emitted across the globe is absorbed by the ocean and seagrass meadows are an important carbon sink.

A new study, recently published in the journal Global Change Biology, investigated how seagrasses can buffer ocean acidification.  The six-year-long study found that these ecosystems can alleviate low ocean pH – that is, more acidic – conditions for extended periods of time, even at night in the absence of photosynthesis. 

In some places, the pH buffering from the seagrasses brings the local environments back to preindustrial pH conditions, like what the ocean might have experienced around the year 1750.

Seagrasses naturally absorb carbon as they photosynthesize when the sun is out, which drives the buffering ability.  The study found the surprising result that the effects of pH buffering even persisted during the night, when there is no photosynthesis.

The study has implications for aquaculture management as well as climate change mitigation, and conservation and restoration efforts.  Globally, seagrass ecosystems are in decline.  These results show how important it is to help them survive and prosper.

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Seagrasses Turn Back the Clock on Ocean Acidification

Photo, posted October 13, 2010, courtesy of Claire Fackler, CINMS, NOAA via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Short-Lived Climate Forcing Pollutants | Earth Wise

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When talking about the causes of climate warming, it is common practice to bundle together various pollutants and express their effects in terms of “CO2 equivalence.”  This involves comparing climate effects of the pollutants on a 100-year timescale.  Recent research from the Institute for Advanced Sustainability Studies in Germany points out the problems with this approach.

One of the worst qualities of carbon dioxide is that it accumulates in the atmosphere.  Once it gets there, it stays there for anywhere from decades to millennia.  On the other hand, short-lived climate forcing pollutants – or SLCPs – stay in the atmosphere for significantly shorter periods.  However, some of these are far more effective at trapping heat in the atmosphere.  As a result, the atmosphere and climate system react much more quickly to reductions in the emission of these pollutants.

The IASS research study determined that reducing SLCP emissions is an important way to slow near-term climate warming as well as having other positive benefits such as reducing air pollution and improving crop yields.  A number of studies indicate that a rapid reduction in SLCP emissions could slow the rate of climate change and reduce the risk of triggering dangerous and potentially irreversible climate tipping points.

Examples of SLCPs are the methane gas emitted from landfills and hydrofluorocarbons that are still widely used as coolants. HFCs only persist in the atmosphere for 15 years but are nearly 4,000 times more effective in trapping heat over a 20-year period.

In order to mitigate the most harmful consequences of climate change, we need to minimize both the near-term climate impacts of SLCPs and the long-term climate impacts of carbon dioxide.

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More Than Just CO2: It’s Time To Tackle Short-Lived Climate-Forcing Pollutants

Photo, posted March 10, 2020, courtesy of Jonathan Cutrer via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Mangrove Trees And Climate Change | Earth Wise

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Mangrove trees are small trees that grow in coastal saline or brackish water at tropical and subtropical latitudes.  Many mangrove trees can be identified by their dense tangle of prop roots.  These roots make the trees appear as if they are standing on stilts above the water.  The tangle of roots allows mangrove trees to handle the daily rise and fall of tides and to slow the movement of tidal waters.  

Mangrove forests provide many ecosystem services, including stabilizing the coastline by reducing erosion from storm surges, waves, and tides.  The intricate root system of mangrove trees are attractive to fish and other species seeking food and shelter from predators.  Mangrove forests also store large amounts of carbon.     

But according to a new study recently published in the journal Science, mangrove trees won’t survive sea level rise by 2050 if greenhouse gas emissions aren’t reduced.  

Using sediment data from 78 locations over the last 10,000 years, an international team of scientists led by Macquarie University in Australia estimated the chances of mangrove trees survival based on the projected rates of future sea-level rise.

When sea level rise rates exceeded 6 millimeters per year, which is similar to estimates under high-emissions scenarios for 2050, researchers found that mangrove trees were unlikely to keep pace with the rising water levels.  But when the annual increase was 5 millimeters or less – which is the projected low-emissions scenario this century – mangrove trees are much more likely to survive. 

These findings underscore the importance of reducing greenhouse gas emissions to mitigate rapid sea level rise.  The future of mangrove trees may depend on it.  

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Mangrove trees won’t survive sea-level rise by 2050 if emissions aren’t cut

Photo, posted December 17, 2012, courtesy of Edward Stojakovic via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Living In Extreme Heat | Earth Wise

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Global climate change has already left observable effects on the planet.  Glaciers have shrunk, trees are flowering sooner, plant and animal ranges have shifted, and so on. Many effects of climate change that scientists had predicted in the past are now occurring.  The loss of sea ice, intensifying heat waves, and accelerating sea level rise are some examples.

According to a new study recently published in the journal Proceedings of the National Academy of Sciences, climate change is going to affect humans earlier, harder, and more widely than previously projected.  The research team found that one billion people will be either displaced or endure insufferable heat for every one degree Celsius rise in global temperatures.  

Under a worst case climate scenario, land that one third of the world’s population currently calls home will be as hot as the hottest parts of the Sahara desert within 50 years.  Even under a more optimistic climate outlook, 1.2 billion people will still be exposed to temperatures outside the climate niche in which humans have thrived for at least 6,000 years.

The majority of the human population has always lived in regions where the average annual temperatures were between 43 degrees Fahrenheit and 82 degrees Fahrenheit.  These are ideal temperatures for human health and for food production.  But this temperature range is shrinking and shifting as a result of climate change. 

The study’s authors predict there will be more change in the next 50 years than there has been in the past 6,000 years.  They hope their findings will convince policymakers to accelerate their plans for emissions reductions and other climate mitigation strategies.   

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Future of the human climate niche

One billion people will live in insufferable heat within 50 years – study

Photo, posted November 22, 2008, courtesy of Ronnie Finger via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Geoengineering And Volcanoes

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Solar geoengineering is a theoretical strategy for curbing the effects of climate change by introducing aerosol particles in the upper atmosphere to reflect some of the Sun’s radiation back into space and thereby cool the planet.  It would basically be intentionally tinkering with the climate system on a global scale.

The concept is fraught with the danger of unintended consequences and most experts consider the idea almost unthinkable.  But there are those who see it as a last resort if all our other efforts to mitigate the effects of climate change are unsuccessful.

Proponents of the idea like to describe the technique as being like a human-made volcano.  Major volcanic eruptions spew ash particles into the atmosphere which can linger for as long as a few years.  The result is cooler temperatures, sometimes across much of the globe.  The Krakatoa eruption of 1883 lowered average Northern Hemisphere temperatures by more than 2 degrees and created chaotic weather patterns until about 1888.

Researchers at the Carnegie Institution and two Chinese research institutions used sophisticated modeling techniques to compare the effects on the climate of a volcanic eruption with long-term geoengineering deployment.

They found that the volcanic eruption created a greater temperature difference between the land and sea than the geoengineering and resulted in very different precipitation scenarios.  In both cases, there would be less available water for people on land.

Overall, the study demonstrated that volcanic eruptions are imperfect analogs for geoengineering and that scientists should be very cautious about extrapolating too much from them.  It is important to evaluate geoengineering from an informed position, but the truth is that it represents a great and perilous unknown.

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Geoengineering Versus A Volcano

Photo, posted November 1, 2002, courtesy of the NASA Goddard Space Flight Center via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

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