Cities are sinking: how will the face of the Earth change?

2024 Author: Seth Attwood | [email protected]. Last modified: 2023-12-16 15:55

Global warming seems to be something distant and unreal: it is still cold in winter, and last year's snow collapse paralyzed half of Europe. But climatologists insist: if the situation is not reversed, 2040 will be the point of no return. How will the face of the Earth change by that time?

The UN Intergovernmental Panel on Climate Change (IPCC) in October 2018 presented a report on possible climate changes in the coming decades that await the planet while maintaining today's level of greenhouse gas emissions.

According to scientists, in 22 years the average temperature on the planet may rise by 1.5 ° C, which will lead to forest fires, droughts, crop failures, extreme natural disasters.

However, today global warming is steadily changing the face of the Earth: some megacities from the Sinking Cities project, which is released from December 1 on Saturdays at 10:00 on the Discovery Channel, may soon go under water, and there will be no trace of entire ecosystems. Here's how global warming is changing our planet right now.

Frozen agony in Patagonia

Patagonia is a unique region stretching from Argentina to Chile. There is a very small population density here, about two inhabitants per square kilometer, but there are much more tourists: they come for a walk in the Chilean Torres del Paine National Park and Los Glaciares National Park in the Argentinean part. Los Glaciares is listed as a UNESCO Natural Heritage Site.

Visitors are attracted mainly by the spectacular split of the Perito Moreno glacier. In total, there are about 50 glaciers in Patagonia, which is why the region is considered the third largest reservoir of fresh water on the planet. But it seems that someone has made a breach in these reservoirs: lately, almost all glaciers of the Patagonian Andes are melting, and at a record speed.

The northern and southern petals of the Patagonian icefield are what remains of a much larger ice sheet that peaked about 18,000 years ago. Although present-day ice fields account for only a small fraction of their former size, they remain the largest ice sheet in the Southern Hemisphere outside Antarctica.

However, their rate of melting is one of the highest on the planet, according to glaciologists at NASA's Earth Laboratory and the University of California, Irvine.

The problem is so acute that the European Space Committee (ESA) has also undertaken to study these processes. Observation from the orbiter showed that there was significant depletion of ice between 2011 and 2017, especially in the northernmost ice fields of Patagonia.

In six years, the Patagonian glaciers retreated at a rate of 21 gigatons, or 21 billion tons per year. Melting water from the Patagonian ice field is driving sea level rise, a process that scientists put in third place after the threatening contribution of the melting glaciers of Greenland and Antarctica.

Going under water: sinking cities

When people talk about cities that will soon be under water, usually the first thing they talk about is Venice. But Venice is a special case: it is more of a frozen history, a conserved luxurious past, to which thousands of travelers from all over the world come to touch. There is almost no real life in Venice: everything here is tailored for the tourism industry, and those who do not want to be a guide, gondolier, museum worker or waiter in a cafe are forced to leave the city.

In Venice, clinics and post offices, banks and company offices are closed - the city is inexorably sinking, and it is quite difficult to keep it afloat, since this is not only due to global warming, but also the very construction of the city and the system of canals (118 islands of the Venetian lagoon are separated by 150 canals and ducts).

Even ancient settlers faced the fact that Venice is sinking under water, and modern inhabitants are born and grow with this knowledge - which cannot be said, for example, about the population of Tokyo or New York.

At the same time, large megalopolises, the largest business, political and industrial centers, where life is in full swing and does not stop even at night, are also on the brink of disaster. According to experts from the project "Sinking Cities" on the Discovery Channel, in Tokyo over the past half century, rainfall has increased by 30%, and in London - by 20% in the last decade alone.

The situation is even worse in Miami, which is only two meters above sea level. Today, the city faces the greatest threat of storms and floods on Earth: groundwater has risen by a record 400% (!) Over the past two years, and each hurricane season (from June to October) increasingly causes colossal damage to the city.

Not only expensive real estate in Miami Beach is at risk, but all structures on the coast, including a nuclear power plant. One of the strongest hurricanes in Miami - "Andrew" - in 1992 killed 65 people, and the destruction is estimated at 45 billion dollars.

At the same time, even after a quarter of a century, the city is not yet ready to give a full-fledged rebuff to the elements: for example, before the prospect of hurricane Irma in September 2017, the Miami authorities did the only thing in their power - they announced the evacuation.

A no less dangerous situation is emerging in other cities of the Sinking Cities project - in New York, London and Tokyo, each of which has to face its own challenges. The British capital is trying to tame the wayward Thames to prevent a recurrence of the 1953 floods caused by the North Sea storm, for which a unique project of a barrier along the river is being implemented: a protective dam reaches 520 meters in length and withstands seven-meter waves.

New York, with its 860-kilometer coastline, is constantly living with the question of whether the city will be able to withstand a new blow of the elements, the number of which is also increasing from year to year.

Each time, experts and government officials say that this hurricane was the worst in the history of the city - and so on until the next storm. Particularly vulnerable is the Manhattan subway (PATH - Port Authority Trans-Hudson - high-speed underground railway of the metro type, connecting Manhattan with the cities of Hoboken, Jersey City, Harrison and Newark).

The centenary system is already in critical condition, and the rising sea level makes it the Achilles heel of the entire city. Tunnels, bridges and commuter rail lines are all of this infrastructure of great concern to engineers and architects. What measures is taken by the mayor's office and what ambitious projects are being thrown to protect the city - see the project "Sinking Cities" on the Discovery Channel.

Great Barrier myth

The world's largest coral reef is the largest natural object on our planet, formed by living organisms. Seen from space, it is listed as a UNESCO World Heritage Site and has been named one of the Seven Natural Wonders of the World by CNN.

The Great Barrier Reef, stretching 2,500 kilometers from the northeastern coast of Australia, surpasses the entire UK in area - and such a unique, huge and complex organism is in danger of becoming a myth soon.

Several factors work against it at once and, in fairness, not all of them are anthropogenic: for example, the crown of thorns starfish that eat coral polyps cause serious damage to the ecosystem - to combat them, scientists have even invented underwater robots that inject poison into the bodies of starfish, reducing their population.

At the same time, global warming poses another threat to the existence of reefs - discoloration, which occurs due to the death of algae when the water temperature rises by at least one degree.

This leads to the formation of "bald spots" on the colonies - colorless areas. Terry Hughes, head of the Center for Coral Reef Research at James Cook University, said that a one-degree rise in temperature has already caused four waves of coral fading in the past 19 years, with color loss reported in 1998, 2002, 2016 and 2017.

These observations correlate with the report of scientists at the Woods Hole Oceanographic Institute: they found that in June 2015, the corals of the South China Sea lost not only color, but also 40% of microorganisms at once in just a week, and this was due to an increase in water temperature by six degrees on an atoll near Dunsha Island. In general, scientists predict that the next rise in temperatures may lead to the complete disappearance of coral reefs, and today the waters of the oceans are warmer than normal by two degrees.

Forests erased from the face

The Amazon rainforest is another unique ecosystem that is endangered, including due to global warming, which is superimposed on the massive deforestation for agricultural purposes.

This vast region of humid tropical evergreen broadleaf forests is the world's largest rainforest, encompassing nearly the entire Amazon basin. The forests themselves stretch over 5.5 million square kilometers, which is half of the total area of the planet's tropical forests.

Increased temperatures and decreased rainfall in some areas can reduce suitable habitat for a wide variety of organisms and potentially lead to an increase in invasive exotic species that will then compete with native species.

Reduced rainfall during the dry months can seriously affect the Amazon forests - as well as other freshwater systems, and the people who rely on these resources. One of the possible detrimental effects of reduced precipitation will be changes in nutrient inputs to rivers, which can severely affect aquatic organisms.

A more volatile climate and extreme weather events could also threaten Amazon fish populations, which will find themselves in unsuitable living conditions.

The Intergovernmental Panel on Climate Change (IPCC) anticipates that sea level rise floods will have a significant impact on low-lying areas such as the Amazon Delta.

In fact, the increase in the level of the World Okan over the past 100 years amounted to 1.0-2.5 millimeters per year, and this figure may increase to five millimeters per year. Rise in sea level and temperature, changes in precipitation and runoff can lead, apparently, and significant changes in mangrove ecosystems.

Development models suggest that temperatures in the Amazon will increase by 2-3 ° C by 2050. At the same time, decreased rainfall during dry months will lead to widespread drought, which will turn 30 to 60% of the Amazon rainforest into savannah …