Cities can choose to be efficient and to have a low carbon emissions per capita as well as other low ecological impacts by choosing the right kind of infrastructure.
Cities also have to plan for the future, a future of rising ecological shocks. Coming from human induced climate change and other trends that are underway. We have to be aware, it’s straightforward, but bears emphasizing that even if humanity does everything it ought to do to head off the worst of climate change. We are still going to be living through decades where average temperatures will be rising and where the number of extreme climate-related events, whether it’s storms, or floods, or droughts, or heatwaves, is going to increase in frequency. This is partly simply a result of inertia of the earth’s climate system. Temperatures have increased on average, worldwide, by about 0.8 of one degree centigrade on the planet since the start of the industrial revolution until today, because of human induced climate change. But even if there were no more increase of the greenhouse gas concentrations in the atmosphere. The planet would continue to warm, just based on what’s happened til now. And that’s because while land has warmed up in response to the greenhouse gas effect, the oceans are still adjusting. The oceans, they’re big bath tubs that take a long time to warm up. So, they have, what the scientists call, thermal inertia. They have not yet caught up with the warming potential coming from the higher greenhouse gas concentrations. As the oceans continue to warm, average temperatures on Earth will continue to rise, even at today’s greenhouse gas concentrations. We could have another 0.6 degrees Centigrade, for example, simply through this catching up effect, as the oceans continue their rise. Of course, we are nowhere near stopping the rise of greenhouse gas concentrations as well, so we’re going to have continuing impacts through more human induced climate change, even as we struggle now to slow down the human impacts and eventually curb them all together. The point is that climate change is with us. It’s going to get worse in the future. And cities have to raise their resiliency in the face of a higher frequency of shocks on the way. What are some of those shocks? Well, heat waves, of course, will be among them. We know that the frequency of intense heat waves is on the rise, and it’s going to get worse.
This is life threatening, especially for elderly people. It needs to be planned for. Water supplies will be under threat in many places in the world. As climate change means changing patterns of precipitation, lower river flow, receding and eventually disappearing glaciers, meaning that what are now a city’s water supply sources could come under serious threat. The rise of ocean levels is another concern of profound significance since the world’s major urban agglomerations are at the coast and as the sea level rises, the kind of devastation that New York City experienced in Hurricane Sandy will become more commons. Major storm surges, major flooding will hit urban areas. Droughts will become more frequent in certain parts of the world, such as the Mediterranean Basin. We know that human induced climate change will cause some places to dry, other places to become wetter. The general principle is, dry places will tend to become drier, wetter places today will tend to become wetter. There are a lot of exceptions to that. More instability and unpredictability ahead, but there certainly are some relatively dry regions, such as southern Europe and north Africa, that are going to become drier and the major cities along the Mediterranean Basin. Some of the world’s great, most historic cities will be under threat of more prolonged droughts. This will contribute, as well, to food insecurity in many cities. And we know that political upheaval often follows food insecurity. Whether it was the high food prices that were one of the triggers of the French Revolution, or whether it was the rising food prices in 2008 and 2009 that were one of the instigators of the massive unrest across North Africa and the Middle East. Food insecurity is part of the scene that cities have to plan for. The reliability of infrastructure is crucial, because infrastructure will come under greater stress. When New Orleans levees broke in 2005, flooding parts of new Orleans and causing massive loss of life and horrendous damage. This was a failure of infrastructure. The engineers, by the way, had warned for years and years that New Orleans’ levees were under threat. They needed to be reinforced. But because of budget constraints, because of putting off for the future what should be done today, one of humanity’s most consistent traits, this wasn’t done. The flev, the levees burst, New Orleans flooded, disaster ensued. Many cities around the world face this kind of risk. They’re being warned of it. They’re not yet taking the risks seriously or adequately seriously. Pollution is likely to worsen as well through combinations of changing weather patterns and in many places, higher proportions of automobiles per household, and other smog-related sources. And so, there are many areas where we know that climate change and other trends that are underway, interacting with rising populations, a more, crowded cities, larger agglomerations, are likely to create, tremendous, tremendous risks. It’s important, of course, for every city to assess those risks in a detailed way. There is no one blueprint, this is for sure. And each city, because of its distinctive topography, location, these would be the ocean location, these would be cyclonic activity, whether it’s the so-called typhoons as the name is given in uhh, in Asia or the hurricanes in the Caribbean and the Southern and East coasts of the United States. Cities need to know, in particular, what the challenges are for them. The United Nations Population Division has done an important classification of the major hazards faced by major cities, identifying cyclones, droughts, earthquakes, floods, landslides, and volcanoes as major hazards that need to be modeled, understood, and to the extent possible, anticipated by the major cities. Many cities along the coast are threatened by cyclones, some of the larger agglomerations threatened by massive cyclones include Tokyo, Shanghai, Manila, Osaka, Guangzhou, China, Shenzhen, near Hong Kong, Seoul and so forth. So many of Asia’s largest cities, many cities are in dry land areas threatened by extreme droughts. Calcutta, Karachi, Pakistan, Los Angeles with its water supply problems, even crisis, one could say. Chennai or Madras in Tamil Nadu state on the east, southeast coast of, of India.Lahore, Pakistan, Ahmad, Ahmadabad, India. Santiago de Chile.
All cities that have a major challenge of water supply and a major risk of drought. Earthquakes, we know. Our cities that sit along the seismic zones, especially, where the tectonic plates meet. And as you can see in this map of seismicity places, where earthquakes have hit, between 1977 and 1992, shown on this map, the heavy concentrations are along the tectonic plates. And many, many cities sit along these areas, of course, California with Los Angeles and San Francisco. the, East Asia, with the, the cities of Japan, of the Philippines, of Indonesia, vulnerable to earthquakes. The cities in the Andean region. The cities in Turkey in the Anatolian Peninsula. Are all highly vulnerable to earthquake, and in the U.N. population division ranking of major cities at top risks of, of earthquakes in the eighth, ninth and tenth, deciles, the highest risks are Los Angeles, Manila, Istanbul, Lima,Tehran, Santiago de Chile, San Francisco, Kunming, China, Nagoya, Japan and Izmir, Turkey. Floods, of course, affect cities along the coasts, that is, most of our large cities, Tokyo, Delhi along the Jamuna River, Mexico City New York, Shanghai, Sao Paulo, Dhaka, in the delta, that is Bangladesh, Calcutta, Buenos Aires, Rio de Janeiro. All cities because of their topography often mountains and hills around them, risks of flash flooding, coastal proximity in, in most cases are highly vulnerable to massive floods as my own city New York experienced in November 2012. Cities in mountain areas of course, highly vulnerable to landslides. And a few cities are vulnerable to volcano, volcanic action such as Akito, Equador. We know that these hazards are on the rise. The frequency of cities being hit by these hazards, the amount of payouts from insurance are all showing a sharp increase, consistent with the idea that we have entered a new era on the planet. The age of the Anthropocene is an era of hydrometeorological threat. As you see in these images of cities in massive flooding in Szechuan Province. New York City in super storm Sandy. In Beijing inundated by massive floods in the middle of 2012.
In Bangkok, a devastation of flood so severe it closed down the economy for weeks. And, because Bangkok is so essential to the global supply chain in industry, closed down a lot of the electronics and automobile sector or at least limited the production seriously for many months after the Bangkok disasters. Cities are not necessarily very well prepared for that, even very sophisticated cities. Here you’re looking at downtown Manhattan. The base of Manhattan in New York City. One of the richest places on the planet. It prides itself in its complete sophistication.It’s all dark. Why? Of course, because the power went out. The grid was not resilient to the flooding in lower Manhattan, many backup generators, even in the hospitals, were in the wrong place, where were they? Unbelievably, they were in the basements, the first places to be flooded and so, major hospitals had to be evacuated as well, all of this is a sign of the lack of forward thinking. Many scientists and urban engineers had been more or less saying for years, New York will be flooded. Of course, the storm that ensued in November 2012 truly was a mega storm, but the warnings had been there about the risks and very, very little preparation had been made. We’re also seeing, because of the confluence of changing weather patterns, often heatwaves. More automobiles more urban pollution because of the lack of clean energy systems, the advent of mega smog episodes and massively dangerous air. China, unfortunately, is now heading the list. China was shocked in early 2013 when a major smog descended on Beijing. That was so heavy, it exceeded by 20 or 30 times the guidelines for particulate pollution in the urban air. It caused the city to come to a screeching halt. It was a terrible shocking wake up call for China in its need to take on the challenge of its massive air pollution. The good news is, it’s possible to do it. Other cities had been there. Other cities that, like China, rely heavily on coal, or relied heavily on coal, and without the precautions of smokestack scrubbers, and other, alternatives to keep the air clean. New York City had its own smog attack, but it was quite a long time ago, more than 40 years ago and since then pollution regulations and especially a shift from coal and a, a move to much cleaner energy sources has enabled the air to be cleaned. London, it’s, as well, was a coal burning city. Like so many of China’s cities are today, that moved away from coal to lower particulate energy sources. Not only does that lower the CO2 emissions, but it cleans the air as well. We know that we have to move also to reduce CO2 emissions, even with clean air We need to move away from fossils fuels to head off the the climate change. But the kind of massive air pollution that is being experienced in China’s cities today is remediable and it’s increasingly urgent, of course, that it is remediated. Cities that are in earthquake zones, we now know, can take preparations. Buildings can be reinforced at very, very low cost. When this is not done, the tragedies that hit Haiti, for example, in January 2010 ensue. In Haiti, hundreds of thousands of people died suddenly in a terrible earthquake. Whose epicenter was just at the city of Port Au Prince. When a similar magnitude earthquake had hit Kobe, Japan a few years earlier, the death toll was high at about 5,000 but nothing like the devastation in Haiti. Haiti is a poor country, had not taken precautions. The buildings were rock or brick buildings without being fortified against earthquake risk. This kind of devastation also can be predicted, can be modeled, and can be avoided through safer zoning, fortified structures, preparation for this kind of, this kind of risk. Finally, with sea levels rising around the world. Cities are finding that they have to think the unthinkable to protect themselves from a sea level that they thought was securely behind ocean walls or fortifications or dykes in the past. But now are surging past these protections and threatening the cities with inundation. The Netherlands is probably the world’s most experienced place in the whole planet of battling the sea level. It is a country that is substantially below sea level, so throughout its history it’s had to create special fortifications, the dykes and other barriers, to protect the Netherlands from sea level flooding. As the seas continue to rise, as Netherlands experienced the horrible episodes of flooding and loss of life in the 1950s. The Netherlands engineers had become world leaders in creative solutions. What to do to protect its great heritage, culture, and major cities from a rising sea level. What you’re looking at here is one of the great acts of foresight and engineering creativity on the planet. What the Netherlands sought to do was to raise the barriers to a rising ocean and to major storms on the ocean that threaten the coasts of the Netherlands and the interior of the country because of its eh, oh, eh, it’s low elevations. And as they thought about this protection, they realized the cost that would attend to a standard engineering design simply to block the ocean from the coastal areas. In estuary areas, where the flow of tides is essential for a healthy ecology. For the shellfish that are among the Dutch pride and joy of their cuisine. And of course, of the more general protection of these ecosystems. The engineers sought solutions that would allow for normal ecosystem functioning, but a preparation in the case of major storms or major storm surges. And what you see here is called the Eastern Shelt Barrier, an ingenious multi-billion dollar creation of Dutch engineering that allows for a protection against sea level through gates that close off during storm surges and during threats of major flooding. But that in normal times remain open to allow for the normal ecology of ocean flow and tidal fluctuations to hold. And this is an example of thinking ahead, of problem solving. Of combining engineering, ecology, and public policy in an absolutely splendid and dazzling way. The Dutch thought ahead. It took more than a decade of planning and thinking to bring this into realization. It has required billions of dollars to do so. But it offers an ecologically smart way for the Netherlands to continue its age old vocation of protecting itself against the sea, but at the same time, loving the coastal ecology and the ecosystems that support the Netherlands and by extension, support all of us around the world. We need that kind of smart engineering, in order to ensure resilience, we need forward looking behavior. We need to combine ecology, engineering, and public policy to keep our cities resilient and desirable places to live. In the 21st Century.
OpenEdition sugere que esta publicação seja citada da seguinte forma:
Pedro Pereira Leite (24 de Abril de 2015). Sustainable Cities IV. Global Heritages. Recuperado em 8 de Outubro de 2024 de https://doi.org/10.58079/p2nl