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Large Mammals And Climate Change | Earth Wise

April 14, 2022 By EarthWise Leave a Comment

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.

The Earth Is Dimming | Earth Wise

November 3, 2021 By EarthWise Leave a Comment

**According to a new study published in the journal Geophysical Research Letters, warming ocean waters have caused a drop in the brightness of the earth.**

Researchers measure the earth’s albedo by observing the light reflected from earth that illuminates the surface of the moon as well as with satellite measurements. The earth reflects about 30% of the sunlight that shines on it. The data shows that the earth now reflects about half a percent less light than it did 20 years ago, with most of the drop occurring in the last three years. That number had been fairly constant for most of the past 20 years.

According to the researchers at the New Jersey Institute of Technology, New York University, and a Spanish astrophysical agency, the apparent cause of the albedo drop has been a reduction of bright, reflective low-lying clouds over the eastern Pacific Ocean in most recent years. That is the same area off the west coasts of North and South America where increases in sea surface temperature have been observed because of the reversal of a climate condition called the Pacific Decadal Oscillation, which is likely a result of global climate change.

The dimming of the earth implies that more solar energy is being absorbed rather than reflected, which may contribute further to global warming.

These results are somewhat surprising. Scientists had postulated that the warming of the earth could lead to more clouds and therefore a higher albedo – more reflection of the sun’s light. If that were the case, it would help to moderate warming and balance the climate system. These new results indicate that the opposite is true.

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The Earth Is Dimming Due To Climate Change

Photo, posted August 18, 2021, courtesy of Arek Socha/GPA Photo Archive via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

People And The Earth’s Increasing Heat | Earth Wise

September 23, 2021 By EarthWise Leave a Comment

A new study by Princeton University and the National Oceanic and Atmospheric Administration had found clear evidence that human activity is the primary cause of the significant increase in heat stored in our planet. In fact, the study found that there is less than a 1% chance that natural variability is the sole cause of the increase.

The researchers looked at data from satellite observations to determine the amount of energy received by the earth and the amount reflected and emitted by the Earth. In a balanced physical system, the amount of incoming energy should equal the amount of outgoing energy. But the earth’s system is not balanced at this point. More energy is coming in than going out, which is driving changes in the climate system. There have been other studies looking at the human influence on the climate, but this new study is the first to examine a 20-year continuous satellite energy balance record to see if natural fluctuations in the climate system or human activities is the primary driver for the significant change in the planet’s energy balance.

The study examined 50 different climate models to look at this energy balance under scenarios where there was no human influence. These include changes in the sun’s output, volcanic eruptions, variations in pollution aerosols, and more.

The results, to no great surprise, are that increasing greenhouse gases over the last twenty years is by far the most important driver for the energy imbalance. This imbalance is what is driving rising temperatures, increasing sea levels, and causing other climate changes.

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Human activities responsible for rapid increase in Earth’s heat

Photo, posted May 6, 2021, courtesy of Marlis Borger via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

The Pandemic And Global Temperatures | Earth Wise

March 12, 2021 By EarthWise Leave a Comment

The early months of the Covid-19 pandemic last year saw dramatic reductions in travel and many forms of commerce. With much of human activity greatly curtailed, greenhouse gas emissions were greatly reduced. And yet, all of that did not slow down global warming: 2020 ended up tied with 2016 as the warmest year on record and atmospheric greenhouse gas levels reached a new high.

In order to understand how this came about, it is necessary to understand the complex climate influences of different types of emissions from power plants, motor vehicles, industrial facilities, and other sources. The fact is that some types of pollution actually have a cooling effect rather than contributing to global warming.

Tiny industrial pollution particles called aerosols actually make clouds brighter, causing them to reflect away more solar heat from the surface of the planet. During the drastic shutdown last year, the biggest emissions decline was from the most polluting industries. The reduction of aerosols had immediate, short-term effects on temperatures. These types of pollutants are very bad for human health, but when they are present, they do have the effect of reducing temperatures.

It is important to keep in mind that carbon dioxide spreads through the Earth’s atmosphere and stays there for a century or more, trapping heat on a global scale. Industrial aerosols stay relatively concentrated in the region where they are emitted and are often removed by rain and winds within a few weeks. So, their cooling effect doesn’t spread very far or last very long.

Overall, the initial pandemic slowdown probably didn’t have any real long-term impact on the climate but over the short term, the effects were not as simple as one might expect.

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Covid-19 Cut Gases That Warm the Globe But a Drop in Other Pollution Boosted Regional Temperatures

Photo, posted July 7, 2020, courtesy of Joey Zanotti via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Better Paint For Cooler Buildings | Earth Wise

August 20, 2020 By EarthWise 2 Comments

A research team led by scientists at UCLA have developed a super-white paint that reflects as much as 98% of incoming heat from the sun. Such paint, if used on rooftops and other parts of buildings, could have a major impact on reducing the costs of keeping buildings cool.

Passive daytime radiative cooling is a well-known method to keep buildings cooler. By having building surfaces reflect sunlight and radiate heat into space, building temperatures can be significantly lowered. This in turn cuts down on air conditioner use and associated carbon emissions.

A roof painted white will result in lower indoor temperatures than a darker roof. But a white roof will do even more: it can reject heat at infrared wavelengths that are invisible to our eyes. This results in even more radiative cooling.

The best performing white paints currently available reflect about 85% of incoming solar radiation. The rest is absorbed by materials in the paint. The new research has identified simple modifications in paint ingredients that lead to a major increase in reflectivity.

Current reflective white paints use titanium dioxide, which absorbs UV radiation and therefore heats up under sunlight. The researchers studied replacing it with other substances such as barite – an artist’s pigment – or with powdered Teflon, both of which allow the paint to reflect more of the sun’s radiation.

Many cities are encouraging the use of cool-roof technologies on new buildings. Using the most reflective coatings possible on rooftops, if applied on a sufficiently large scale, could have a real impact on climate change as well as saving significant amounts of energy used for running air conditioners in buildings.

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UCLA-led Team Develops Ways to Keep Buildings Cool with Improved Super White Paints

Photo, posted August 15, 2012, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

A See-Through Heat Shield

January 8, 2019 By EarthWise Leave a Comment

It is estimated that air conditioners use about 6% of all the electricity produced in the United States for an annual cost of $29 billion. With rising temperatures, this expense is only going to get larger.

A significant part of the heat load in buildings arises from heat coming through windows. It turns out that for every square meter of window, about 500 watts of heat energy can be brought in by sunlight, equivalent to 5 old-fashioned light bulbs.

Researchers at MIT and the University of Hong Kong have developed a heat-rejecting film that can applied to a building’s windows that will reflect 70% of the sun’s incoming heat. The film is similar to transparent plastic wrap. It remains highly transparent at temperatures below 89 degrees Fahrenheit. Above that temperature, tiny microparticles embedded in the film shrink and the film becomes more translucent or frosted, still letting in a good amount of light, but rejecting a lot of heat.

There are already so-called smart windows on the market, similar to the electrochromic mirrors in cars that darken to prevent trailing headlights from blinding drivers. But that technology is not very effective in rejecting heat and it requires power to operate, which means you would have to pay to turn windows opaque.

Tests of the new film demonstrated its ability to reject heat and lower temperatures. The researchers estimate that if every exterior-facing window in a building were covered in the heat-rejecting film, the building’s air conditioning and energy costs could drop by 10%. Saving ten percent of tens of billions of dollars is no minor matter.

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See-through film rejects 70 percent of incoming solar heat

Photo courtesy of MIT researchers/MIT.

Earth Wise is a production of WAMC Northeast Public Radio.