Oceans are our main allies in the fight against global warming, but they are also the first ones to pay its price. In the next decades, we will have to deal with both rising seas and freshwater resources in scarcity: a challenge that can turn into an opportunity for technological innovation. Climate change: impacts and adaptation scenarios is the theme of the conference that will take place on Friday, May 19, at Slow Fish.
Even if we don’t realize it, global warming is especially destructive where we can’t see it: in sea waters. Ninety-four percent of anthropogenic greenhouse gas effect is stored in the seas, not in the atmosphere. To understand how waters absorb carbon dioxide like a sponge, just think that only four square meters of depth can contain all of the Earth’s heat.
“The ability of the oceans to absorb heat is about 4,000 times greater,” says physicist and climatologist Vincenzo Ferrara, former manager of ENEA (Italian National Agency for New Technologies, Energy, and Sustainable Economic Development) and national representative of the IPCC (Intergovernmental Panel on Climate Change). Waters are at the forefront of the environmental struggle and are therefore more exposed to the effects of global warming. Increasing temperatures, melting icebergs, currents and geological movements all take part in the rising of our oceans.
“The level of the oceans,” explains Ferrara, “is increasing at a faster pace than what was estimated by the most pessimistic forecasts: we are at an average of more than three millimeters per year – although it is not everywhere that the phenomenon is observed to this level.” A primary factor to take into consideration is the fact that –like for anything that is subject to the laws of physics– warming of waters causes their expansion.
We must also add the effects of melting ice and another variable that often is overlooked, the centrifugal force of the planet which is much higher in Ecuador, where seas could rise by a meter over the course of this century. In the Mediterranean, rising should be about 20 centimeters, but it is expected to be greater in the Levantine Sea and less in the Mediterranean.
Ferrara also warns us not to forget about what happens in the crust and explains the problem through the example of Italy: “The soil is exposed to geological phenomena that, for example, mean Italy is subject to a movement tending to collapse in the North, especially in the upper Adriatic, and to a lifting in its southern regions.”
As a consequence, in this case, numbers may vary to be either over or under the general estimates. If you think of a rising of 50 to 60 centimeters in the Adriatic, the Calabrian and Sicilian coasts will be much less affected. Already these days, drought has been reducing and jeopardizing many cultivations in the northeast. River Adige is dry and the sea rises to the fields, resulting in sandy soils and depositing of mullet and cuttlefish in the middle of the countryside.
Water scarcity remains the real drama, expected to cover the entire peninsula in the next decades if the situation isn’t solved: “In many coastal zones, sea waters seep into freshwater aquifers. This is particularly obvious in the Po delta, where sea water intrusion has arrived as far as twenty kilometers off the sea, and indeed in the Northeast marked by severe wastes of crops such as corn.” Agriculture – the sector that uses 70% of the drinking water – is the main cause for this waste, but it can also be the agent of change if it manages to adopt more efficient and clean systems.
“The measures to be taken,” says Ferrara, “are already available.” It involves first, to avoid spray irrigation, promoting the use of drip systems and rationalizing the management of drainage and irrigation associations, and drinking and industrial water services. In short, a more integrated and balanced management of the entire water cycle, in which we as consumers can do our part as well: for instance, by remembering that one pound of meat costs the environment fifteen to twenty thousand liters of water, and wasting food means a thirsty planet.
In the next decades, environmental issues will not just concern sustainable development, but our own social and economic model. “Becoming more energy efficient means a step forward in economic development,” says Ferrara and reminds that “the fight against climate change should not necessarily be a burden but it can turn into an opportunity for technological innovation. Those who are able to innovate will also be able to take a global leadership role in the future.”
by Andrea Cascioli