Residents of low lying regions, such as Florida, have new reasons to worry after new research has revealed that sea level rise will occur much faster than had been previously predicted. The earlier estimates called for a sea level rise of about one meter by the end of this century. However, these calculations did not factor in significant melting and shrinkage of the ice sheets in Antarctica, which climate scientists had thought to be more or less stable. Now it is known that these ice sheets are not stable at all, and are in fact collapsing precipitously. The new information doubles the expected sea level rise; from one meter to two meters by the year 2100.

For Florida, which has many residents and much critical infrastructure close to the shoreline, this news is disheartening to say the least. A rise of two meters will incur great damage to many important municipal areas, including Miami, Fort Lauderdale, Fort Myers, and Tampa. Particularly hard hit would be the Everglades, which would be awash in salt water incursions that could spell the end of this unique ecosystem. The famous (and densely populated) Florida Keys would also be grievously affected, with up to 50% of the current land mass slipping beneath the waves. As of today, almost 80,000 people live in the Keys. If the current projections for sea level rise become a reality, or if these dire predictions are even surpassed by our failure to reduce greenhouse gases, many of these 80,000 people will lose their homes and communities.

The very low topography of southern Florida is evident in this color-coded shaded relief map generated with data from the Shuttle Radar Topography Mission. The image on the left is a standard view, with the green colors indicating low elevations, rising through yellow and tan, to white at the highest elevations. In this exaggerated view even those highest elevations are only about 60 meters (197 feet) above sea level. For the view on the right, elevations below 5 meters (16 feet) above sea level have been colored blue, and lighter blue indicates elevations below 10 meters (33 feet). This is a dramatic demonstration of how Florida’s low topography, especially along the coastline, make it especially vulnerable to flooding associated with storm surges. Planners can use data like these to predict which areas are in the most danger and help develop mitigation plans in the event of particular flood events. Image Courtesy SRTM Team NASA/JPL/NIMA. Source: earthobservatory.nasa.gov

Unfortunately, sea level rise is not the only dreadful consequence of unchecked carbon emissions. It is now known that weather patterns will be altered in such a way as to greatly increase both the frequency and intensity of storms — and this is already happening in the present day. Ferocious storms, in combination with rising sea level, spells flooding disaster for major metropolises around the world: from New York to Jakarta. Even at current the sea level, cities like Boston and Tampa are extremely vulnerable to the major “100-year” storms that seem to hit annually these days. At the turn of the next century, only 84 years from now, some of these huge population centers may no longer be defensible. A worldwide retreat from the coastline will most likely take place … unless carbon emissions are brought under control in time. Scientists have previously predicted these dire consequences for the planet, but now the damage may well be suffered by people alive today, not by our unborn descendants.

While many countries are working to reduce carbon emissions, the new research in Antarctica indicates that significant reductions in greenhouse gases must take place quite soon in order to stave off disastrous sea level rise which will doom coastal regions around the world to incessant floods and inundation by the seas. Incredibly, scientists have discovered that the entire planet is already wobbling on its axis in a new and different way — this is caused by the planet’s shifting weight distribution as ice melts at the poles and in Greenland. The good news is that it is still not too late to alter this future of flooding and storm surge — we need only work cooperatively to bring the emissions to a safe level. New technologies like solar, wind, and biomass energy production, if adequately funded and supported by prudent legislation, can help reduce our dependency on fossil fuels. If nations around the world get serious about abandoning dirty technologies, the ice sheets of Antarctica may still be salvageable … along with the cities of New York and Mumbai.

Source:: FloodBarrierUSA

As floods become more frequent and much more severe, novel ways of fighting them are cropping up all over the world. In some cases, the “new” flood control techniques may be in fact a return to ancient practices that have been lost in recent times. This may be the case with the recent enthusiasm for the introduction (or re-introduction) of farming practices that can help prevent or reduce flooding in the towns and cities located nearby.

Farmers rely heavily on water for their livelihood. Too much water or too little water — both of these scenarios can spell disaster for those who produce our food supply. Some flood control engineers are advocating for a natural approach to water and soil conservation that will, it is claimed, provide reliable water for the farmers and help protect nearby communities from flooding.

Roller/crimper demonstrated on cover crops. Photo: www.nrcs.usda.gov

The new measures call for several methods of flood control. One idea is to encourage farmers to allow some designated part of their land to be given over to flooding in the event of major precipitation rather than blocking the water — which would in many cases mean directing floods toward population centers. In this case, a farmer might permit some flooding of some cropland in order to protect more developed land. A bonus of this practice is that the flooded land becomes more fertile, having the benefit of alluvial deposits. Of course, in allowing some land to be given over to flooding, the farmer loses the productivity of that land for some time, so most localities are arranging for financial compensation for farmers who participate.

Another method of flood reduction is called conservation tillage. This practice entails simply leaving the fields covered with the stalks, roots, and other debris from last year’s crops. Something as simple as this can make a huge difference in the amount of runoff during storms and can greatly reduce the soil erosion that comes with it. There are many other benefits; including increasing rich organic matter in the soil, improving water and air quality, attracting beneficial earthworm colonies, and even providing sustenance and shelter for wildlife.

But the most important reward of conservation tillage is that it helps to hold water on the land. The stalks of the harvested crops, if left in place, provide shade on the land, preventing much of the evaporation that would occur on completely denuded fields. In addition, the stalks act as tiny dams during heavy rains, slowing the water long enough for it to soak into the ground rather than just running off the land. Wind erosion is also greatly decreased in these fields, and much less dust (and topsoil) flies off with the winds.

While all of these other benefits of conservation tillage may be of great value to farmers, food consumers, and earthworms; when it comes to preventing floods in nearby towns, the most important benefit of conservation tillage is the great reduction of “soil sealing”. Soil sealing is the result of raindrops hitting bare soil, a process that compacts the soil and makes it impermeable to water infiltration. Soil that has been compacted and sealed by hard rains will not easily absorb water, and the water will run off in the same way it runs off asphalt. Fields that are covered with stalks and old root systems will not suffer this compaction, and the water will be slowed down enough to sink into the permeable soil.

As climate change, harmful human activity, and rising sea levels all contribute to an increase in floods and major storms, we will need to change our practices on many levels to reduce the resulting destruction and damage. Conservation tillage is likely to become one of the many useful techniques borrowed from the past that will help ensure a better future.

Source:: FloodBarrierUSA