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1- Major changes in high mountains affecting downstream communities
2- Melting ice, rising seas
3- More frequent extreme sea level events
4- Changing ocean ecosystems
5- Declining arctic sea ice, thawing permafrost
6- Knowledge for urgent action

    However, this is not the only problem, as the retreat of glaciers is also generating changes in the availability and quantity of water in the mountains. There are also repercussions on many sectors such as agriculture, hydroelectricity, tourism, recreational activities...

    In order for these regions to adapt as well as possible, warming should be limited, which would slow down the melting of glaciers, otherwise, by 2100, small glaciers will lose 80% of their mass and the risks in the mountains will be more and more important. But it would also allow a better adaptation to changes in water supply even if solutions are already in place such as the integrated water management and transboundary cooperation.

Emissions of greenhouse gases have significant impact on the present and future of human societies. These gases increase the temperature at the Earth's surface, indirectly melt glaciers, icebergs.

As a consequence, the level of the oceans increases dramatically and the oceans continue to warm. So, to avoid an excessive increase in ocean levels from 60 to 100 cm, it would be necessary, by 2100, to drastically reduce greenhouse gas emissions so that this change in ocean level remains between 30 and 60 cm. However, a study shows that this impact should be revised upwards because the ice caps could have a much greater effect than what was expected.  This remains difficult to determine. So, the rise in sea and ocean levels is linked to how the ice caps will react.

3- MORE FREQUENT EXTREME SEA LEVEL EVENTS

By 2050, the middle of the 21st century, reports indicate that some island nations, coastal cities will disappear under water. Indeed, the rise in sea level will cause this phenomenon, in addition to the extreme and rare events that used to occur only once a century and will occur at least once a year, regardless of the degree of global warming. Moreover, the dangers already present will be further aggravated by an increase in the magnitude of storm surges, etc., and what is more, if greenhouse gases remain as high. All in all, it is difficult to predict whether an area will be habitable or not at the present time, because the thresholds of habitability remain extremely difficult to assess. But various adaptation approaches are already being implemented, to put in place elaborate responses to the future rise in sea levels.

The report is saying that 90% of the excessive heat of the climate system, the global warming that the oceans are facing today might increase the heat taken by the ocean from 2 to 4 times the actual heat. The warming of the oceans is a danger to ocean lifeforms because it could reduce the supply of oxygen and nutrients for some species.
The marine heat waves did increase in intensity and in frequency since 1982 because of global warming and are likely to go on if it continues to warm up.
The oceans of the globe are acidifying because of the absorption of human-created carbon dioxide, according to the report, by 2100 the acidification of the ocean could reach levels that would put in danger fauna and flora of our oceans.

The extend of Arctic sea ice is decreasing and the ice is getting thinner. As a result, the indigenous people have already adjusted to these changes as well as to the climate change related emergency. Arctic and boreal permafrost are known to contain large amounts of carbon. If the carbon is released, it will speed up the production of greenhouse gases. If the emission of greenhouse gases is not significantly reduced, we could quickly lose 70% of Arctic sea ice surface. Scientists predict a total thaw of permafrost by 2100.