Clearly, sea level rise is one of the most alarming signs of climate change. Due to various factors, earth’s oceans have expanded to such an extent that they have started disrupting lives on land. Here are some anecdotes on sea level rise.
Why they’re expanding:
Increased ocean temperatures is one of the key factors behind the seawater rising. The increased heat due to regional phenomena, such as El Niño, which is a periodic warming of the eastern tropical Pacific is making the water expand. Changes in the precipitation and evaporation that feeds the glaciers and ice sheets of Greenland, Antarctica, which fluctuate over the decades is added with extra meltwater from melting ice sheets and glaciers. All these factors combined are causing the sea levels to rise faster and with more velocity than it normally would.
How do we know:
One of the earliest attempts of keeping long-term records of sea-level rise can be found in ancient Venice. Marks cut into building walls gave way to tide gauges in the 19th and 20th centuries and, by the dawn of the 21st, satellite altimetry, with gravimetry soon to follow. Nature, on the other hand, has been keeping proxy records. How? Sedimentary deposits kept over thousands of years by ocean organisms and the action of waves against rock and salt marshes all laid in front of us by mother nature for scientists to analyze. Archeological sites, such as the Roman columns of the Phlagrean Field also stored data that revealed that they were submerged and uplifted by the sea over the years. Then there were the Greeks. Scientists of ancient Greece made connections between climate, the planet’s spherical shape and its angle to the sun. By the 19th century, the role of greenhouse gases and their impact on the climate became clear and were taken seriously. By the beginning of the 20th century, this was being modelled with fluid-filled globes for science students and scientists to study. And by the mid 1950’s, the first low-speed computer simulations appeared. Now there are super computers working day and night keeping records of the ocean with modelling ensembles such as the Coupled Model Intercomparison Project (CMIP). Although these measuring technologies are increasing in accuracy day by day, challenges remain in accurately tracking clouds, precipitation and extreme events.
What do we do now:
It is by no doubt clear that climate change is the main cause and effect of sea-level rise. Now the question remains is how to deal with it. Global policymakers have come up with two primary responses to the situation. One is mitigation, or direct intervention such as cutting back greenhouse gas emissions, and the other is adaption to whatever change may come. The mitigation process is already running in full swing, with world economies agreeing to reduce or stop using coal-powered fuel to produce electricity. Now if all that doesn’t work, the only way to cope with the changes would be to adapt. And there are some challenges we’ll be facing if we want to adapt. Rising temperatures and sea level, increased coastal flooding and perturbation of weather patterns are among the changes likely to require an adaptive response.
A recent projection has shown that if we don’t learn to adapt, 0.2 to 4.6 of Earth’s population, which makes some 10 million people are likely to see annual flooding by the year 2100, and a 25 to 123 centimeter (0.8 to 4 foot) rise in global mean sea level. That translates to yearly losses in gross domestic product of 0.3 to 9.3 percent. Precautions such as construction of dikes for coastal protection, would bring yearly investment and maintenance costs to $12 to $71 billion by 2100–likely a far smaller figure than the cost of the damages that would otherwise be unavoidable.
But there is no other way. Old fables tell tales of Noah building an ark to save the earth’s living things from a massive flood. But if this kind of change in climate becomes permanent then we’re gonna need a lot more than an ark.