Sea levels could rise by a meter

These should be prepared for a sea level rise of one meter and more by the end of the century, warns a study published on Tuesday by the umbrella organization of the European science academies EASAC, in which experts assessed the state of the North Atlantic and the consequences of its changes for two years .

According to the study, the direct effects of global climate change can be seen in the rise in the surface temperature of the Atlantic by almost one degree Celsius since the 1890s, in the rise in sea levels in the 20th century by eleven to 16 centimeters and in the fall in the pH value of seawater since the beginning of the industrial revolution by about 0.1 pH units. The latest findings on the melting glaciers and ice sheets in Greenland and Antarctica would show that sea level rise is accelerating.

“The European countries would be well advised to prepare for an increase of one meter or more by 2100,” said Michael Norton, Environment Director of EASAC, to which the Austrian Academy of Sciences (ÖAW) also belongs, in a broadcast. This plus is not only due to a combination of the thermal expansion of the oceans and the additional water from the melting of the ice masses. The loss of the Antarctic ice mass, which will change its attraction to the oceans, will have a major impact. “When Antarctica melts, water masses move towards the northern hemisphere and sea levels rise even faster around Europe,” said Norton.

A critical factor in Europe’s climate is the Atlantic Meridional Overturning Circulation (AMOC), part of the global ocean circulation currents caused by differences in temperature and salt concentration. The AMOC transports large amounts of heat from the subtropics to the Arctic and when it collapsed 12,000 years ago it caused massive cooling in Europe.

Models would suggest that the AMOC is weakening with global warming. However, according to the EASAC study, the latest measurements show that the periodic fluctuations do not yet reveal any clear trends. But because this circulation is so important and changes not only have dramatic consequences for Europe but also for the climate thousands of kilometers away and could affect hundreds of millions of people, the scientists are calling for an early warning system.

The rising levels of carbon dioxide in the atmosphere are also causing the world’s oceans to acidify – a trend that could be exacerbated by changes in water circulation. According to the study, there is a lack of information to assess the risks associated with acidification for marine ecosystems and commercial fisheries, which also indicates that the warming of the oceans is already reducing the yields of fisheries. In order to achieve sustainable fisheries, it is necessary to understand much better how marine ecosystems react to climate change.

Changes in ocean currents and the associated weather could also affect the supply of renewable energy. The study refers to studies in the North Sea, according to which changes in future wind patterns could lead to a three percent decrease in the energy generated in offshore wind farms.

“We have already warmed the planet so that the ice melts – but how quickly that happens is crucial for our future,” said EASAC expert group chairman Tor Eldevik from the University of Bergen (Norway). “Future ocean changes depend on the success or failure of stopping global warming.” According to scientists, there is only one possible remedy: emissions should be reduced and carbon uptake through forests and other carbon sinks increased.