Atlantic Ocean Currents Appear To Be Changing; So May Hurricane Season

Tropical Storm Alberto on May 18, 2018, in the Gulf of Mexico    Photo: NOAA/NASA

In a little-noticed report that could have major implications for both the Eastern U.S. and Europe, scientists announced last week that Atlantic Ocean currents are thought to be 15% weaker than in 1950The Washington Post explained, saying that the “system of currents that includes the Florida Current and the Gulf Stream, is now ‘in its weakest state in over a millennium,'” and this could make Europe colder in the winter and raise the rate of sea-level rise in the U.S. Atlantic seaboard. Similarly, a group of government scientists is looking at whether to change the official start of the Atlantic Hurricane season from June 1 to May 15 due to an increase in “early” tropical storms recently.

Why This Matters: We need to understand both these phenomena better to predict climate events.  They are quite a coincidence.  The warming of the Atlantic seems to be having profound and potentially permanent impacts on the Earth’s circulation system and on fisheries.  While the early storms may not be full-fledged hurricanes, they can cause damage–like  Tropical Storm Alberto in late May 2018, which caused nearly a foot of rainfall in central Florida.  And Friend of the Planet, Michael Mann, believes the slowdown in Atlantic currents is real even if the evidence is based on a mosaic of evidence.

The Current Slow Down

Scientists had long suspected the slowdown of the three major currents in the Atlantic, but it is hard to have definitive observations of these currents given that they have only had definitive measurements since 2004.  The new study published in Nature Geoscience found 11 sources of “proxy” evidence of the circulation’s strength, including clues hidden in seafloor mud as well as patterns of ocean temperatures. These currents are important because they transfer heat northward toward Europe and that moderates their climate. They redistribute heat worldwide, in fact, also bringing cool air and water to the south.  Parts of the Atlantic are getting markedly warmer — like the Gulf of Maine off the Northeastern U.S., which is warming faster than any other part of the Atlantic.  One of the most striking pieces of evidence, according to Michael Mann, is a recurrent “cold blob” that is not going away in the ocean to the south of Greenland —  and it is going against the overall global warming trend overall.

Longer Hurricane Season

The last six years have all had a named storm – though none were hurricanes – in May, and there have been 11 named storms in May since 2000. The National Hurricane Center told the Washington Post in an email, “Many of the May systems are short-lived, hybrid (subtropical) systems that are now being identified because of better monitoring and policy changes that now name subtropical storms.”  In fact, the average first storm of the season is now more than a month earlier than it was in 1970, but some of that change may be attributable to better storm detection thanks to modern weather satellites.  The hurricane season start date is really just a formality — it helps to get the public focused on storm preparation.  And it’s only about a hundred days away now.  Forecasters fear that this season could once again be active like last year, given the observed La Niña weather pattern and a number of other atmospheric factors.

Up Next

US Green Diplomat Previews Glasgow

US Green Diplomat Previews Glasgow

By WW0 Staff For the United States, the post-Trump, pre-COP26 road to Glasgow has been paved with ambition and humility. In a major speech, the President’s Envoy, John Kerry, previewed the results of his climate diplomacy before heading into two weeks of intense deliberations of world leaders. Speaking at the London School of Economics — […]

Continue Reading 421 words
One Cool Thing: COP26 Coverage Kickoff

One Cool Thing: COP26 Coverage Kickoff

Next week, the COP26 climate conference in Glasgow will draw hundreds of world leaders to Glasgow to determine the path forward five years after the Paris Climate Agreement (for a primer, read this) as new science underscores the urgency. The conference aims to squeeze countries to strengthen the commitments they’ve made towards securing global net-zero […]

Continue Reading 194 words
DOD Says Climate Change Increases National Security Risks

DOD Says Climate Change Increases National Security Risks

By Amy Lupica, ODP Daily Editor In a report released last week, the Department of Defense (DOD) confirmed that existing risks and security challenges in the US are being made worse due to “increasing temperatures; changing precipitation patterns; and more frequent, intense, and unpredictable extreme weather conditions caused by climate change. Now, the Pentagon is […]

Continue Reading 440 words

Want the planet in your inbox?

Subscribe to the email that top lawmakers, renowned scientists, and thousands of concerned citizens turn to each morning for the latest environmental news and analysis.