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Climate change seriously damages the world's oceans, new major report warns



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Coral reefs are threatened by acidification of the oceans

Climate change is devastating our seas and frozen regions as never before, a major new report from the United Nations warns.

According to a group of UN scientists, the waters are increasing, the ice is melting and the species are moving because of the habitat of human activities.

And the loss of permanently frozen lands threatens to release even more carbon, accelerating the decline.

There is some protection that the worst impacts with deep and immediate carbon reductions can be avoided.

This is the third of a series of special reports produced by the Intergovernmental Panel on Climate Change (IPCC) in the last 1

2 months.

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Once due mainly to the thermal expansion of the oceans, sea level rise is now mainly due to the melting of Greenland and Antarctica

Scientists have previously considered how the world would handle if temperatures rose by 1.5C by the end of this century. They also report how Earth's land will be affected by climate change.

However, this new study examining the effects of rising temperatures on our oceans and frozen regions is perhaps the most worrying and depressing of the three.

So what did they find and how bad it was?

In two words, the waters are warming, the ice in the world is melting fast, and this has an impact on almost every living being on the planet.

"The Blue Planet is in grave danger right now, it is suffering a lot of insults from many different directions and it is our fault," said Dr. Jean-Pierre Gatuso, lead coordinator of the report.

Scientists are "almost certain" that the global ocean has now warmed without a break since 1970.

Water has soaked more than 90% of the extra heat generated by humans in recent decades, and the rate at which it has absorbed this heat has doubled since 1993.

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Qaleraliq glacier, southern Greenland

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  Satellite image of Qaleraliq glacier, Greenland in 2018

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  Satellite image of Qaleraliq glacier, Greenland in 1993

Where the seas are rising After rising mainly due to thermal expansion, IP CC says this is mainly due to the melting of Greenland and Antarctica.

Thanks to the warming, the loss of mass from the Antarctic Glacier in the years 2007 to 2016 tripled compared to 10 years earlier.

Greenland noted a doubling of mass losses over the same period, the report expects to continue throughout the 21st century and beyond.

For glaciers in regions such as the tropical Andes, Central Europe and North Asia, projections are that they will lose. 80% of its ice by 2100 under a high carbon scenario. This will have huge consequences for millions of people.

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Glaciers around the world are rapidly losing their ice

What are the consequences of all this melting ice?

All this extra water gushing out to the seas leads to average levels of ocean water around the world. This will continue for decades to come.

This new report states that the global average sea level could rise to 1.1 million by 2100 under the worst case scenario. This is a 10 cm increase from previous IPCC forecasts due to the greater ice loss that is now occurring in Antarctica.

"What surprised me the most was the fact that the highest planned sea level rise was revised upwards and is now 1.1 meters," says CNRS's Dr. Jean-Pierre Gatuso, National Agency for research in France.

"This will have widespread implications for the low-lying coastline, where nearly 700 million people live, and this is disturbing."

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countries will be greatly affected by rising sea levels

The report makes it clear that some island states are likely to become uninhabited after 2100.

Scientists also say that moving people away from endangered communities is worth considering "if there are safe alternative places."

What will these changes mean to you?

One of the key messages is that the warming of the oceans and cryosphere (ice shards on land) is part of a chain of bad results that will affect millions of people well into the future,

in higher emissions scenarios even affluent metropolitan areas such as New York or Shanghai and large tropical agricultural deltas such as the Mekong will face a high or very high risk of rising sea levels.

The report states that a world with severely increased levels of warm water, in turn, will cause large increases in nasty and dangerous weather events, such as tropical cyclone jumps.

"Historically rare marine events (once a century in the recent past) are predicted to occur frequently (at least once a year) in many places by 2050," the study said, even if future carbon emissions "19659007]" What we see now is lasting and unprecedented, "said Prof. Debra Roberts, co-chair of the IICC Working Group.

" Even if you live in the interior of the world, the changes in the climate system caused by the very big changes in the ocean and the cryosphere will affect the way you live your lives and opportunities for sustainable development. "

The ways you can be hit are huge – flood damage can increase by two or three orders of magnitude. The acidification of the oceans by increasing CO2 is a threat to corals to such an extent that even at 1.5C warming, about 90% will disappear.

Fish species will move as ocean temperatures rise. Seafood safety may even be compromised as humans may be exposed to elevated levels of mercury and persistent organic pollutants in marine plants and animals pollutants are separated from the combustion of the same fossil fuels that emit climate warming CO2.

Even our ability to generate electricity will be impaired as warming melts glaciers, altering the availability of water for hydroelectricity.


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Melting permafrost can add billions of tonnes of CO2 to the atmosphere

Eternal freezing is not so constant

Huge amounts of carbon are stored in the permanently frozen regions of the world, such as in Siberia and northern Canada.

They are likely to change dramatically, with about 70% of the near surface eternal freezing set to thaw if emissions continue to increase.

The great concern is that this can release "tens to hundreds of billions of tons" of CO2 and methane into the atmosphere by 2100. This would be a significant limitation on our ability to curb global warming in the coming centuries.

So what happens in the long run?

This is a key question and it depends a lot on what we are doing in the near future to limit our emissions.

However, there are some warnings in the report that certain changes may not be easily reversed. Antarctica data suggest the emergence of "irreversible ice sheet instability", which can see sea levels rise by several meters over centuries.

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Climate change can force species to move their range

"We provide this information for sea level rise to 2300 and the reason for this is that there are many changes, closed, to ice sheets and the contribution that will need to be raised to sea level," said Dr. Nerilie Abram, who is the lead author of the report.

"So even in a scenario where we can reduce greenhouse gases, there is still a future rise in sea level that people will have to plan for."

There can also be significant and irreversible loss of cultural knowledge. due to the fact that the fish species that the indigenous communities rely on can be relocated to escape from warming.

Does the report offer any hope?

Yes. Definitely. The report makes a strong play on the fact that the future of our oceans is still in our hands.

The formula is well-worn at this stage – deep, rapid carbon reductions in line with last year's IPCC report, which required a 45% reduction by 2030.

"If we dramatically reduce emissions, the impact on people and their livelihoods will still be difficult, but possibly easier for those who are most vulnerable, ”said Hoesung Lee, chairman of the IPCC.

In fact, some of the scientists involved in the report believe that public pressure on politicians is a crucial part of growing ambition.

"After the demonstrations of young people last week, I think they are the best chance for us," said Dr. Jean-Pierre Gatuso.

"They are dynamic, they are active. I hope they will continue and they will make society change."

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