Industrial Revolution

Ocean Acidification And Mass Extinction

November 26, 2019 By EarthWise Leave a Comment

Since the industrial revolution, the concentration of carbon dioxide in the atmosphere has increased due to the burning of fossil fuels and land use changes. The ocean absorbs about 30% of the CO2 that is released in the atmosphere. As the levels of atmospheric CO2 increase, so do the levels in the ocean.

When CO2 is absorbed by the ocean, a series of chemical reactions occur, resulting in seawater becoming more acidic. Ocean acidification threatens calcifying organisms, such as clams and corals, as well as other marine animals, like fish. When these organisms are at risk, the entire marine ecosystem may also be at risk.

In fact, according to research recently published in the journal Proceedings of the National Academy of Sciences, fossil evidence from 66 million years ago has revealed that ocean acidification can cause the mass extinction of marine life. Researchers analyzed seashells in sediment laid down shortly after a giant meteorite hit earth. This strike wiped out the dinosaurs and 75% of marine species. Chemical analysis of the shells revealed a sharp drop in the PH of the ocean over hundreds of years after the meteorite strike. The meteorite impact vaporized rocks, causing carbonic acid and sulphuric acid to rain down, acidifying the ocean. The strike also resulted in mass die-off of plants on land, increasing atmospheric CO2.

Researchers found that the pH dropped by 0.25 pH units in the 100 to 1,000 years after the meteorite strike. Alarmingly, scientists expect the pH of the ocean to drop by 0.4 pH units by 2100 if our carbon emissions continue as projected.

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Ocean acidification can cause mass extinctions, fossils reveal

Photo, posted March 16, 2017, courtesy of Zachary Martin via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Shrinking Arctic Glaciers

March 18, 2019 By EarthWise Leave a Comment

The glaciers on Baffin Island, located in Canada’s northeastern Arctic, have been shrinking as the climate warms. The melting, receding glaciers have exposed fragments of ancient plants that had frozen in the places where they once grew. New research has shown that these spots have not seen the light of day for at least 40,000 years.

The entire planet has been warming since humanity started flooding the atmosphere with greenhouse gases at the start of the Industrial Revolution, but the effects are not uniform across the globe. Some regions – like the Arctic – are seeing temperature rises that are greater and faster than anywhere else in the world. As a result, glaciers in the Arctic have been melting away at rates never before observed in modern human history.

Researchers at the University of Colorado performed radiocarbon dating experiments in order to find out when the last time was that the Arctic was as warm as today. There have been natural variations in Arctic temperatures caused by the complicated way the Earth wobbles on its axis. For example, 10,000 years ago the northern latitudes pointed at the sun more directly during the summer than they do now, providing about 9% more sunshine during the summer.

The results of the study showed that the newly-uncovered plants had died at least 40,000 years earlier, indicating that the glaciers had not melted back to today’s size for at least that long. Global measurements indicate that the planet as a whole has not been as warm as it is today for about 115,000 years, back then again a result of the orientation of the Earth.

Well, the Earth hasn’t wobbled recently. The Arctic is melting because we are dumping massive amounts of greenhouse gases into the atmosphere.

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These Arctic glaciers are smaller than ever before in human history

Photo, posted September 1, 2010, courtesy of Doryce S. via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

The End Of British Coal

November 3, 2017 By EarthWise Leave a Comment

In the 19th century, Britain produced 80% of the world’s coal. Britain was the dominant global power in the industrial revolution with its giant blast furnaces, steam locomotives and steam ships. And with advent of the electric age, coal once again was the power source of choice. Even as late as the 1970s, Britain got 80% of its electricity from burning coal.

Arguing Against Climate Change

April 3, 2017 By EarthWise

Most of the world has accepted the analysis of the overwhelming majority of climate scientists that shows that our planet is warming and that our actions are the primary cause. However, some people – notably a number holding high office – reject this analysis. What exactly does it imply to say that climate change is not happening or is not caused by us?

Carbon Dioxide Continues To Rise

November 7, 2016 By WAMC WEB

Back in December of 2013, a little less than three years ago, Earth Wise reported that the observatory on Mauna Loa in Hawaii had briefly measured carbon dioxide levels greater than 400 parts per million for the first time ever. During the following year, readings above the 400 level started to pop up occasionally elsewhere as well.

The Missing Sink

November 18, 2015 By WAMC WEB

One of the puzzles of atmospheric chemistry is why carbon dioxide concentrations in our atmosphere aren’t rising even faster. Our activities emit some 37 billion metric tons of carbon dioxide each year. About 45% stays in the atmosphere, 25% is taken up by the oceans. The rest is a bit of a mystery.

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