I will talk about Iceland, a land almost on the extreme of the world that is affected more than others, in shorter times, by the actions conducted by mankind since the “distant” industrial revolution. I ventured into this land because of my love for Nature. As a result of the passion that drives you, what comes out is always something that involves you, contorts you and somehow leaves you with a bitter-sweet feeling. Before my arrival in Iceland, I expected to find a harsh winter and a more northern landscape. Iceland is an island located in the North-Eastern Atlantic that has just over 338000 inhabitants, of which about half live in the capital, Reykjavik. It is a particular land characterized by:
- the nearby formation of the North Atlantic Deep Water (NADW, the deepest water for most of the Atlantic ocean) in the North Sea and the Labrador Sea due to deep convection processes. With this mechanism, the water affected by cold polar winds acquires a greater density and sinks;
- and by the presence of the Gulf Stream that moves back to the North American coasts, reaching the island and having a natural mitigation effect on the climate, especially on the South.
Here, therefore, two masses of water that seem to be at the antipodes essentially interact, yet coexist, linked by a subtle balance.
When we move towards North, what does not stand out in everyday perception becomes clearly visible. I hate conspiracy theorists and honestly I don’t like to think that science always says the truth. From a standpoint of almost a scientist, I understand and I know that science has made mistakes many times, it has corrected them, and it failed again. However, one thing that science is right about, is that global climate change is happening, really. Unfortunately, there are evidences and data collection that prove it. What is most unsettling is not the fact that temperature is changing, because this can be determined equally by natural processes of heating and cooling of the Earth, that for centuries and millennia have characterized the climate. So, what leaves science without words is the speed with which this change is happening. We have been able to accelerate natural processes that normally take place on much longer timescales, all for one purpose: the economy.
In the future projections, it is expected that the temperature will continue to increase everywhere, with a greater force at high latitudes (at the poles), and with a raise that might even go up to 15°C . This is the so-called global warming phenomenon throughout which the planet will warm up, especially in the colder regions. Global change is determined by several factors, such as the increase of temperature (the most tangible), the increase in atmospheric CO2 and the reduction of stratospheric ozone layer (with an increase in incident UV radiation).
An augment in salinity and temperature has therefore been observed in Icelandic and adjacent waters over the last two decades. This has generated changes in the abundance and distribution of many species, thus modifying the entire trophic chain. Some of these changes seem to be related to the inflow of the Atlantic waters in those of the North of the Iceland, leading to the expansion of some species with effects (negative or not) on the purely endemic species. Recent and continuous changes in the Icelndic marine environment also affect multiple organisms that are an important prey for cetaceans. Considering the ecological flexibility of the different species, these changes can regulate the presence of cetaceans in this area. Taking into consideration the blue whale (Balaenoptera musculus), in the last years, it has been affected by the lack of krill, showing a continuous decrease in sightings off the Western Icelandic coast. It is clear that early thawing leads to a decrease in krill abundance, which happens because the krill feeds on phytoplankton adherent to the icy substrate and in the water column. In the years in which thawing occurs early, the availability of phytoplankton adherent to the substrate is limited. The distribution rate of krill, therefore, decreases drastically, having an effect on the blue whale population.
Climate change has also been studied in common eider (Somateria mollissima, a sea duck) in a colony of the South-West of Iceland. The climatic fluctuations affect the life of these animals in the phase of reproduction and subsequent survival of the born. In general, these birds have responded positively to global warming. They have generated a higher number of nests from year to year during the breeding season and an anticipated spawning has occurred. This advance in the deposition is typical of the eiders of the South-West of Iceland. They are residents of this area, and so are more easily influenced by local climate compared to other species that migrate. However, a series of multiple factors seem to influence the population growth synergistically: the presence of a mild climate, low predation rate and food availability. According to the habitat, the tolerance and the type of destabilization that occur at the level of the trophic chain, some species can survive better or even grow demographically, following the climate change, compared to others. Let us remember, however, that a positive effect in itself does not prove to be natural but a consequence of artificially generated climatic and environmental factors that disrupt the entire ecosystem of a target species.
The Intergovernmental Panel of Climate Change (IPCC) of 2007 shows an increase in atmospheric temperature in the last century of 0,74°C , as well as in the sea surface temperature of the ocean with an avrage of 0,67°C . All this, leads to the thawing of the ice, the retreat of the glaciers, and the progressive fusion of the permafrost, with a rise of the sea level of about 25 cm in the last century. Speaking of Iceland, from 1975 to 2008, the overheating rate is 0,35°C per decade, which is substantially greater than the trend of the average global overheating of about 0,2°C per decade. But we actually expect this as a direct consequence of global warming. However, the long-term warming rate in Iceland is similar to the global one, suggesting that recent heating is a combination of local variability and large-scale warming.
Today, what can still be done to remedy and restore the natural condition of the oceans is practically minimal, if not zero. Even if at this moment we were to interrupt the emissions of greenhouse gasses (which is improbable), the effects would last for several years. The stabilization of CO2 levels would occur only after a time interval of 100 – 300 years, while the temperature would take a few centuries to recover. The sea level, instead, will be very difficult to control and could require millennia to stabilize. Furthermore, the models for the forecast of atmospheric CO2 rates show an increase of the same up to 1000 ppm by 2100 (against 400 ppm today and above all, against the 280 ppm of the pre-industrial era). This increase will generate an acidification of the oceans, with direct effect also on the calcification processes (which may or may not change, depending on the organisms). We must consider that global warming will lead to a greater water stratification (with the retention of nutrients at the bottom), which will push the entire trophic chain towards the more superficial waters. This shift will also take the organisms to a greater UV exposure and a higher sensitivity to UV stress – damage of DNA, production of reactive oxygen species (ROS) – all exacerbated by nutritional deficiency.
Nature is fragile and it is regulated by a labile equilibrium which has already been compromised. In my opinion, the thing that we can do today, is change our lifestyle. We need to become conscious about the fact that every our action can have negative effects on the global scale, on land and in the oceans. We are the ones making the market – without a request, there is no offer generated. We are the ones pushing the world toward the chasm because nothing is ever enough. We are the ones incapable of understanding what really matters for our body and mind because we are blinded by the yearning to possess. We are unable to support sustainable agriculture, farms and fishing. We need to understand that we cannot ask Nature more than she is able to give us. There is lack of amazement of everything that Nature continues to offer despite our conduct. Something can change, and we CAN do it. And we MUST to do it.