Monday, July 15, 2019

The Ocean / Climate Nexus

Our oceans provide two-thirds of the planet's atmospheric oxygen, absorb more than 90 percent of the Earth's excess heat energy and more than a quarter of the globe's anthropogenic carbon emissions. Warmer and more acidic oceans are decimating marine ecosystems, killing coral, kelp, shellfish starfish and plankton. Warmer oceans also have adverse implications for global weather including more intense storms.

Balmy sea-surface temperatures expedite terrestrial warming and reduce the time we have to reign in climate change causing greenhouse gas emissions. If we do not stop spewing carbon and other greenhouse gases into the atmosphere we are on track to see anywhere from five to seven degrees of warming in the coming decades.

Warmer seas mean less ice and this can further contribute to the warming trend. According to National Snow and Ice Data Center (NSIDC), the monthly June ice extent over the last 20 years shows a decline of 4.08 percent per decade. The average extent for June 2019 was the second lowest in the satellite record. One of the implications of melting sea ice is a weakened jet stream which wreaks havoc with the weather in much of the world.

One of the most troubling corrolaries of warmer seas involves the breakdown of the ocean food chain.  Plankton, the basis of the oceans food chain, is dying and this is causing low oxygen dead zones where nothing can survive.

According to research published in the journal Bulletin of Mathematical Biology from the University of Leicester in the UK, rising ocean temperatures is causing massive reductions in plankton populations. Since plankton is responsible for two-thirds of atmospheric oxygen, this could cause the Earth’s oxygen levels to fall dramatically, and this in turn could kill massive numbers of people and animals.

The policy implications are clear, governments need to take unprecedented action to keep ocean temperatures as low as possible.

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