circulation

Shrinking Glaciers And Methane | Earth Wise

August 1, 2023 By EarthWise Leave a Comment

The Arctic region is warming much faster than the rest of the planet. In fact, according to a study published last year in the journal Nature, the Arctic has been warming nearly four times faster than the rest of the globe during the last 43 years. This rapid warming is leading to substantial reductions in sea ice, thawing of permafrost, shifts in wildlife populations, and changes in ocean circulation patterns, among other changes.

According to new research recently published in the journal Nature Geoscience, shrinking glaciers in the warming Arctic are exposing bubbling groundwater springs, which could provide an underestimated source of methane, a potent greenhouse gas. Methane is more than 25 times as potent as carbon dioxide at trapping heat in the atmosphere.

The study, which was led by researchers from the University of Cambridge and the University Centre in Svalbard, Norway, found large sources of methane gas leaking from groundwater springs unveiled by melting glaciers.

As glaciers retreat in the Norwegian archipelago of Svalbard and leave behind newly exposed land, groundwater beneath the Earth seeps upward and forms springs. In 122 out of the 123 springs studied, the research team found that the water was highly concentrated with dissolved methane. When the spring water reaches the surface, the excess methane can escape to the atmosphere.

Researchers are concerned that additional methane emissions released by the Arctic thaw could dramatically increase human-induced global warming. If this phenomenon in the Svalbard archipelago is found to be more widespread across the Arctic — where temperatures are quickly rising and glaciers melting — the methane emissions could have global implications.

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The Arctic has warmed nearly four times faster than the globe since 1979

Shrinking Arctic glaciers are unearthing a new source of methane

Photo, posted October 22, 2022, courtesy of David Stanley via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Less Phytoplankton In The Gulf Of Maine | Earth Wise

July 20, 2022 By EarthWise Leave a Comment

Phytoplankton, also known as microalgae, are the base of the marine food web and also play a key role in removing carbon dioxide from the air. They are eaten by primary consumers like zooplankton, small fish, and crustaceans.

Phytoplankton, like land plants, absorb carbon dioxide from the atmosphere and use photosynthesis to grow. Then they become a food source for other organisms and ultimately for people who depend upon marine ecosystems. If phytoplankton productivity is disrupted, there can be adverse effects on regional fisheries and the communities that depend on them.

The Gulf of Maine is becoming warmer and saltier, because of ocean currents pushing warm water into the gulf from the Northwest Atlantic. These temperature and salinity changes have led to a significant decrease in the productivity of phytoplankton. According to a new paper from scientists at Bigelow Laboratory of Ocean Sciences in Maine, phytoplankton are about 65% less productive in the gulf than they were 20 years ago.

The study’s results come from the analysis of the Gulf of Maine North Atlantic Time Series, a 23-year sampling program of the temperature, salinity, chemical, biological, and optical measurements of the gulf. The scientists refer to what they describe as a giant windmill effect happening in the North Atlantic, which is changing the circulation of water coming into the Gulf of Maine. In the past, inflows from the North Atlantic brought water from the Labrador Current, which made the gulf cooler and fresher. The new circulation is making the water warmer and saltier.

These changes have significant implications for higher marine species, fisheries, the lobster industry, and other activities in the states that border the Gulf of Maine.

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NASA-funded Study: Gulf of Maine’s Phytoplankton Productivity Down 65%

Photo, posted November 15, 2015, courtesy of Paul VanDerWerf via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Living in a Carbon Bubble | Earth Wise

July 18, 2022 By EarthWise Leave a Comment

The earth’s atmosphere is a little over 0.04% carbon dioxide, currently about 420 parts per million. That’s more than it’s been in millions of years and is changing our climate. But these levels of CO2 are not enough to directly affect people.

However, people are sensitive to the amount of carbon dioxide they are breathing. It is actually an indoor pollutant. High concentrations have been shown to reduce our cognitive performance, our health, and our comfort. For example, a study in 2012 showed that performance in a variety of cognitive function tests was reduced by 12% when CO2 levels reached 1,000 parts per million and by 51% at 2,500 ppm.

How common are high levels of carbon dioxide? Pretty common. Offices often have CO2 levels of 600 ppm or higher, but 5% of US offices have average concentration about 1000 ppm and some conference rooms can reach 1900 ppm. Classrooms often reach average levels above 1000 ppm. Passenger aircraft have average levels around 1400 ppm during flight, and can peak over 4,000 ppm. Cars with one occupant with the windows closed and the air recirculating have levels above 4,000 ppm.

Where does it all come from? From us. We exhale CO2 and if we are in enclosed spaces with insufficient air circulation and ventilation, we end up living in a carbon dioxide bubble. Most of us live with high CO2 levels – all day and every day. It is a form of indoor pollution that has not gotten enough attention.

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I’m living in a carbon bubble. Literally.

Photo, posted October 24, 2013, courtesy of Cory W. Watts via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

The Coastal Northeast Is A Hotspot | Earth Wise

November 16, 2021 By EarthWise Leave a Comment

Global warming is, obviously, a world-wide phenomenon. When the concept of a 2 degrees Celsius temperature rise is discussed, it refers to the average global temperature and the effects that would have on such things as sea level rise and weather patterns. But the effects of the changing climate are not homogeneous. Very different things can happen and are happening in different places.

One such place is the coastal northeastern United States, which is a global warming hotspot. The region is heating faster than most regions of North America and, indeed, 2 degrees of summer warming has already happened in the Northeast.

New research led by the University of Massachusetts Amherst has determined that this heating is linked to significant alterations in the ocean and atmospheric conditions over the North Atlantic.

Several studies have found that the Atlantic Meridional Circulation is slowing down. The AMOC conveys warm, salty water from the tropics north towards Greenland, where it cools and sinks. The cooled water than flows back south as deep-water currents. As the warming climate melts glaciers in Greenland, the circulation slows down, less cooled water arrives in the south, and there is more heating of the ocean off the Northeastern coast.

At the same time, the North Atlantic Oscillation, a weather phenomenon that governs the strength and position of the winds that blow from the U.S. over the Atlantic, has tended to settle into a pattern that enhances the influence of ocean air on the eastern seaboard climate. Warmer ocean air being blown over the region has led to rising temperatures in Boston, New York, and Providence, Rhode Island.

As the average temperature of the world rises, some places will warm more quickly and others more slowly.

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The Coastal Northeastern U.S. Is A Global Warming Hotspot

Photo, posted August 8, 2010, courtesy of Doug Kerr via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.