The threat of the oceans, between pollution and …

The the oceans, which have played a central role in the evolution and survival of millions of species, become a global threat generated, above all, by the interference of the human being. If CO2 pollution is not reduced the UN revealed in the draft report that will be debated in Monaco in the coming weeks, The oceans will not only be a huge threat to small island nations and coastal communities, but will also have a significant impact on the world's largest economies..

The the oceans absorb a quarter of CO2 emissions, as well as over 90% of the additional heat generated by greenhouse gas emissions since 1970. Without this marine sponge, the heat on Earth would be unbearable for the species.

But the excess of CO2 caused by the man, the Intergovernmental Panel on Climate Change (IPCC) warned in the special report on oceans and icy zones (cryosphere), It has a cost: acidification, which changes the food chain of the ocean, and offshore heat waves, which create large dead zones.

Experts said that pollution generated by the major economic powers could in the future marked decline in fish stocks, multiplied by thousand the damage caused by cyclones and left hundreds of millions homeless due to sea level rise.

This rise in sea level, melting glaciers, could exceed more than a hundred times the current levels towards the end of the 21st century. In addition, experts warned that the permafrost surface of the northern hemisphere could melt between 30% and 99% and record an explosion of CO2 and methane emissions, further accelerating global warming.

These changes in the oceans, caused by pollution, leave humans extremely protected. According to the IPCC, even if the most optimistic emission reduction scenarios were given, 2050 many low-lying mega-cities and small island nations will experience "extreme events" related to sea level each year. 2100in the meantime, the annual damage caused by the floods will multiply on a scale from 100 to 1,000.

Since the end of the 19th century, global average temperature has increased by 1 ° C. At this rate, the IPCC explained, by the end of the 21st century, it is expected to increase by another 2-3 degrees. This is why the Paris agreement recommends limiting the rise to less than 2 ° C. However, although its magnitude can be halted, much of the damage is already caused: even if the world manages to limit warming to 2 ° C, the level of the oceans will increase enough to move 280 million people in 2100.

Although this is a problem that affects all countries of the world, the proposals of the largest emitters of CO2 – China, United States, India and those of the European Union- they might not live in the climatic emergency. On 23 September, they will meet in New York at a summit convened by UN Secretary General Antonio Guterres to secure greater national commitments to combat global warming.

China

"Beijing has less and less focus on environmental issuesLi Shuo, badyst of Chinese climate policy in Greenpeace, said Li. Shuo. The resurgence of nationwide coal plants and the relaxation of air pollution standards suggest that China's main concerns are the economic slowdown and the trade war with the United States.

According to the emissions database for global atmospheric research, China emitted 10.8 gigabytes of carbon dioxide in 2017, about 29 percent of the global total. If emissions continue to rise at the current rate, Shanghai could face an annual rise in sea level of 2.6 millimeters during this century. In addition, one study found that of the 20 cities in the world with the highest risk, nine are Chinese.

United States

United States, historically the most emitting countryit has large coastal cities and is particularly vulnerable to rising sea levels. However, the President Donald Trump wants to get his country out of the Paris deal and broke the climate policies of his predecessor, Barack Obama.

According to the IPCC report, sea ​​level rise of 1.2 meters in a century could quintuple the areas affected by the floods on the east coast. Another study warned that New York could experience flooding of 2.25 meters once every five years between 2030-2045. Meanwhile, the east coast has already been hit by several devastating cyclones between 2005 and 2012.

European Union

EU aims for zero net emissions target but several Member States hesitate. In 2017, the EU produced 3.5 gigatonnes of CO2.

In general, Europe is less exposed to the risks of rising sea levels, although the IPCC report mentions a risk of flooding in the Rhine Delta, a major commercial artery. An increase in temperature, due to emissions, could also slow down the meteorological phenomenon called South Atlantic return circulation, resulting in more powerful winter storms on the mainland.

India

About 260 million people, that is to say a fifth of the Indian population lives in coastal areas which, in recent years, have suffered an increase in storms due to climate change. As the country develops solar energy, it continues to build coal plants.

Harjeet Singh of NGO ActionAid said that India was the most vulnerable country to sea level rise and stressed that millions of people would be displaced in the coming decades. "The question is where they will go," he reflected. "We are talking about one of the most populous countries in the world, which means that conflicts will eventually break out between resident and displaced populations. We are on a time bomb, "he warned.