Rising sea levels are making the days longer, according to The Hindu. The earth is rotating more slowly, and as a result, the time that it takes for that dark shadow (otherwise known as “night”) to move around the globe is getting longer and longer.
Environmentalist activists have seized upon the finding. One headline from the Albany Daily Star declared “Climate Change Decreased Earth’s Spin Speed.” The article quotes Harvard researchers who have studied the relationship between the earth’s rotation speed, melting glaciers, human activity, and the length of a day.
While the degree to which human activity plays a part in causing climate change is disputed (most researchers agree that human activity has at least some impact, probably a significant one), it is agreed that the Earth’s rotational slowdown is set to become more pronounced.
The IPCC says that the world’s glaciers will slump by between 15% and 85% by 2100, depending on how sharply nations reduce deforestation and cut greenhouse gas emissions.
A recent study found that the melting of the world’s glaciers that we are seeing today is “historically unprecedented.” Many are indeed convinced that it is human caused climate change that is responsible for melting the glaciers and slowing the earth’s rotation.
The Sydney Morning Herald notes that the day is indeed getting longer, but the rate at which this change is happening is very slow:
Don’t forget to set your clocks ahead two thousandths of a second before you go to sleep tonight.
In fact, the Earth’s speed has always been changing, and so have the length of its days.
“We naively think there always has been 24 hours per day. But that is not the case.”
Experts say that at the time of the Jurassic dinosaurs the day was about 23 hours long. Two hundred million years from now it will be 25-hours long.
NDTV notes that this is a cumulative effect that adds up over time. Projections allow scientists to confidently predict how far sea levels will have risen by the end of the 21st century. This will allow for preparation by those immediately affected, such as people living in coastal towns.
Researchers warned that making such preparations could be expensive:
“This can help to better prepare coastal towns, for example, to cope with climate change. We’re talking billions of dollars of infrastructure here.”
People on social media have reflected – sometimes humorously, sometimes skeptically, and sometimes with alarm – on the slowing of the Earth as it rotates on its axis.
But what would happen if the Earth stood still? ESRI reports that the continents would all drift together at the equator, forming a single “supercontinent,” and days on that supercontinent would be long indeed — in fact, a day would be the same length as a year.
You might think this sounds all right, and that there could even be some benefits – sunny equatorial weather for everyone on earth, the elimination of any need for perilous seafaring journeys, and being able to drive to literally any other country by car – but experts warn that there will be some disastrous consequences. That is because a stationary Earth would experience gravity in a very different way.
[We could expect] a catastrophic change in climate and disastrous geologic adjustments (expressed as devastating earthquakes) to the transforming equipotential gravitational state.
We would also see dramatic and rapid shifts in the shape of our oceans, probably necessitating a mass human migration away from all coastal areas.
Today, all three world oceans are connected. This creates a global ocean with basically one sea level. As a consequence of rotational slowdown, the outline of the global ocean would continuously undergo dramatic changes.
(Image via DSCOVR/NASA)