The Arctic is a habitat for specialists. Species living in the High North have successfully adapted to the local challenges by using the most amazing tricks. Yet the future of all these survivors is uncertain; over the past few decades, the living conditions in the Arctic have changed more rapidly than in virtually any other ecosystem on the planet.

Broad expanses of the Arctic Ocean and the Southern Ocean in the Antarctic are covered in sea ice. The ice plays a vital role in our climate system and is an important component of Arctic and Antarctic habitats.

Around the world, sea level is rising. This poses a risk for the nearly 600 million people living in coastal regions, while it represents an existential threat to small island nations.

Even in the most remote parts of the ocean, like the polar regions or the bottom of the deep sea, we can find large amounts of plastic debris that have accumulated over the past few decades. Tiny microplastic particles have been found in seawater and drinking water alike, and a recent study has revealed that nearly all species of marine flora and fauna come into contact with plastic debris in their natural habitats – often with harmful consequences. …

Hardly any other sea in the world is used as intensively as the North Sea. And it remains a treasure trove of biodiversity. But, especially due to climate change, the sea at our doorstep is now undergoing unprecedented changes.

The Wadden Sea is currently changing faster than it has in millennia. The biotic community in and on the sand and mud has been massively transformed – and will continue to do so, since there are on average one or two newly introduced species every year. These new rivals change native diversity and species interactions – though a few of native species are actually benefiting from the developments.

Our planet’s oceans absorb tremendous amounts of carbon dioxide. Instead of causing atmospheric temperatures to rise further, the greenhouse gas dissolves in the water. But this service provided by the oceans comes at a price. The more greenhouse gas the oceans remove from the atmosphere, the more acidic their waters become.

The Weddell Sea is one of the few remaining marine regions in the world that are largely untouched and one of the most biologically significant regions of the Antarctic. Consequently, for several years now there have been plans to protect a large section of the Weddell Sea in order to preserve its unique diversity for future generations.

The deep sea is the largest ecosystem on our planet: roughly 65 percent of the Earth’s surface is covered by this underwater world. Yet it still holds many mysteries.

Thanks to natural climate archives like seafloor sediments and ice cores, as well as measurement data from past decades, researchers can accurately reconstruct climate developments in the past. When a model accurately simulates the past, it can also project the future, paving the way for forecasts on e.g. future sea-level rise or global warming.