miles

Record Low Antarctic Sea Ice | Earth Wise

March 2, 2023 By EarthWise Leave a Comment

Recent satellite observations of the sea ice in the Antarctic found the lowest level of ice cover ever seen in the forty years that these observations have been made. As of February 8th, there were only 849,000 square miles of the Southern Ocean covered with ice. The previous record low was measured last February 24th when the total coverage was 876,000 square miles. Ice melting was likely to continue as the month went on.

This past January had already set a new record for that month’s mean extent of ice coverage at 1.24 million square miles. This rapid decline in sea ice has been going on for the past six years and is very unusual. Average Antarctic ice cover hardly changed at all during the previous thirty-five years.

Antarctic sea ice generally reaches its maximum extent in September or October and its minimum extent in February. At its maximum, the sea ice cover in the Antarctic is generally between 6.9 and 7.7 million square miles. On the other hand, there are some places where the sea ice melts completely during the Southern Hemisphere summer. Sea ice varies much more in the Antarctic than in the Arctic where the ice is much thicker.

Climate warming at the poles is much higher than at lower latitudes. Nonetheless, it is not yet clear whether what we are seeing is the beginning of the end of summer sea ice in the Antarctic, or whether this is just a new phase characterized by low but still stable sea ice cover in the summer.

**********

Web Links

Record low sea ice cover in the Antarctic

Photo, posted January 24, 2012, courtesy of Rob Oo via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

How Green Are Electric Cars? | Earth Wise

April 12, 2021 By EarthWise Leave a Comment

Environmental groups, governments, and automakers are all promoting electric vehicles as an important technology to combat climate change. For example, GM plans to stop selling gas-powered cars by 2035 and Volvo intends to be all-electric by 2030.

There are still those who question how green electric vehicles actually are. All products and technologies do have their environmental impacts. In general, today’s electric cars produce significantly fewer planet-warming emissions than gas-powered cars, but there are factors that affect the results for specific vehicles.

The biggest issue is the source of electricity used to charge up the cars. In places where coal still provides a substantial fraction of electric generation, electric cars don’t fare as well. But coal’s contributions to the grid are declining rapidly and even cleaner fossil fuels like natural gas are gradually being replaced by green generation from wind and solar power. If the grid was entirely carbon-free, then there would be no emissions associated with operating the vehicle.

MIT has created an interactive online tool that incorporates a comprehensive set of factors contributing to the emissions associated with cars: what it takes to manufacture the cars, how much gasoline conventional cars burn, and where the electricity to charge electric vehicles comes from.

The tool provides information like the average amount of carbon dioxide emitted for every mile driven over a car’s lifetime.

Results will vary with location and various other vehicle factors, but in the great majority of cases, electric cars are much greener than gasoline cars, and as the grid becomes greener, the cars will become greener as well.

**********

Web Links

CarbonCounter 2021

How Green Are Electric Vehicles?

Photo, posted January 29, 2020, courtesy of Tony Webster via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Wildlife And The Border Wall

February 14, 2019 By EarthWise Leave a Comment

The border between the United States and Mexico is nearly 2,000 miles long, stretching from San Ysidro, California to Brownsville, Texas. Discontinuous barriers currently cover approximately 650 miles of our southern border. As the particulars of how to better secure the remaining 1,350 miles of border are worked out, one thing is abundantly clear: extending physical barriers would negatively impact wildlife and the environment.

The Trump Administration has called for a 1,000-mile wall, which would cut across land that includes important habitats for wildlife. According to an article signed by nearly 3,000 scientists, this plan would “threaten some of the continent’s most biologically diverse regions” by inhibiting species movement and triggering flooding. The paper, which was published in the journal Bioscience, highlights how more than 1,500 native animal and plant species would be affected by the wall, including 62 that are listed as endangered or vulnerable.

An extended border wall would not only impede movement of many wildlife species but it would also put pressure on creatures already in peril, such as the Mexican gray wolf and the Sonoran pronghorn. Other at risk animals include the ocelot, black bear, and desert bighorn sheep.

According to researchers, extending the border wall could cause problems for low-flying birds and insects. Even plants, including the endangered wildflower Zapata bladderpod and the threatened whiskerbush cactus, are particularly at risk.

According to a 2011 study, bird-watching and other forms of ecotourism in the Lower Rio Grande Valley brought in more than $344 million in economic activity and approximately 4,400 jobs.

Preserving our natural heritage must be part of this national security discussion.

**********

Web Links

Nature Divided, Scientists United: US–Mexico Border Wall Threatens Biodiversity and Binational Conservation

Photo, posted December 14, 2014, courtesy of Tony Webster via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Misconceptions About Electric Cars

February 8, 2019 By EarthWise Leave a Comment

Tesla’s Model 3 was one of the best-selling cars in the United States last year, eclipsing all but a handful of sedans. This was the first time that an electric car had that honor and is indicative of how electric cars are finally becoming mainstream. A host of other new electric models from multiple manufacturers will be the entering the market over the next couple of years.

Despite all of this progress, there is still a great deal of misinformation about electric cars. A new study commissioned by Volkswagen revealed some of the widespread misconceptions about the vehicles.

Some people believe that electric cars can’t be driven through puddles. Nearly one in five people believe that electric cars slow down as the battery depletes. Many people believe that electric cars are fundamentally less safe than gas-powered cars.

More generally, people are unaware of how far current electric cars can drive on a charge. More and more models can go 200 and even over 300 miles between charging sessions. People also don’t know how quickly cars can charge up either. Fast chargers like Tesla’s Superchargers can add 200 miles worth of charge in about 20 minutes. And people don’t know what it costs to charge electric cars. In most places, it is only a fraction of what it costs to drive the same distance using gasoline.

Despite their limited knowledge about electric cars, the 2,000 people surveyed in Britain were positively disposed towards them with nearly 6 in 10 saying that they would like to own an electric car some day and would even consider one as their next vehicle.

Electric cars will become more familiar and less exotic as more and more of them are on our roads and highways.

**********

Web Links

Major misconceptions prevent drivers from buying electric cars, study claims

Photo, posted April 6, 2018, courtesy of Brian Doyle via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

https://www.independent.co.uk/news/uk/home-news/electric-cars-misconceptions-battery-charging-safety-volkswagen-study-results-a8700536.html