Transcript Document
7.2 How can these challenges be managed? 7.2b Different strategies can be used to manage SOCIAL and ENVIRONMENTAL CHALLENGES in DEVELOPING world cities. Lesson 8- Today we will EVALUATE the advantages and disadvantages of attempts to develop less POLLUTED cities in the DEVELOPING WORLD. What are the advantages and disadvantages of improving Mexico City’ environment? Has a population of 21 million people – is one of the world’s largest cities. It is also a city with three serious environmental challenges, which it is vigorously addressing: air pollution, waste disposal and water pollution. In 1998 UN voted it the most dangerous city for children- who were dying at much younger ages than other children. 1000 deaths and 35,000 hospital admissions were attributed to air pollution Due to its location in a depression, and being surrounded by mountains, pollutants get trapped over the city. 5 million car journeys in and out of the city each day. The waste disposal problem Mexico City produces 13,000 tonnes of rubbish every day – but the waste collection system can only remove 9,000 tonnes In 2012 the biggest dump in the city, Bordo Poniente was closed, but no alternative was suggested. This resulted in a build up of rubbish The closed site had been used since 1985 and was receiving 12,000 tonnes per day. In 2012 Mexico City was sending 3,600 tonnes of rubbish per day to landfill, 3,000 tonnes were going to make compost and 800 tonnes was used to make plastic bottles. The rest had no designated destination. The rest is dumped on open ground, and in waterways, streets and drains, where it clogs the system. Worse still, 70 million tonnes of waste had been buried underground at Bordo and this was causing serious water and air pollution. The water pollution problem Water supply and pollution are major challenges for Mexico City. As the city has grown, the problem has arisen as a result of population growth and the over-exploitation of underground water supplies. This has been made worse by a failure to recycle and a failure to build sewage-treatment plants. For many years the only solution to the lack of water was to pump water up from the 514 underground aquifers. This has now gone so far that the land surface of the city is sinking at the rate of 9 cm per year. This is causing water and gas pipes to fracture and roads to crack, as the aquifers start to dry up. Worse still, each person in Mexico City uses 320 litres of water each day and this excessive consumption is causing problems for sewage plants which cannot cope with the volume. Changing the legal formula for petrol and diesel so that they now contain fewer pollutants. Building a new $2 billion underground train line which will reduce the number of cars and reduce average commuting times from 150 minutes to 78 minutes. Moving – or closing down – the worst polluting factories. Aim of schemeto reduce the number of vehicles that go through the city everyday (over 5 million), recovering public space, reducing pollution, and improving life quality Introduced in 2009. 275 stations + 4,000 bicycles across city 50,000 trips have been taken throughout the city thus far The bikes have small racks to hold bags or groceries, adjustable seats, and automatic lights. One person switching from driving to cycling, for a 12 mile roundtrip (6 miles each way), saves 1.3 metric tons of CO2 emissions per year! http://www.youtube.com/watch?v =HhS5Dl14_mI Every Sunday the main finance area of the city is closed to all traffic, except bikes, so that residents can bike around an area that they deem to dangerous on other days of the week. Only a small area of the city is closed to vehicles. Residents are not permitted to drive their car into the city one day a week, but richer residents get around it by having 2 cars. Some of the cities oldest and narrowest streets have been pedestrianised to make room for free flow of buses, bikes and pedestrians, and marketplaces have been established for street vendors to help unclog the corridors. "If you want to walk to the Zócalo now, you can walk directly on the pedestrian promenade," Hook said. "It used to be that that street was just choked with traffic." EcoParq A new parking system, called ecoParq, introduced meters to thousands of parking spots on Mexico city streets where parking previously had been free—officially free, anyway. In reality, much on-street parking was controlled by unregulated valets or attendants known as franeleros, who would stake out territories and charge drivers small fees to park and receive protection in their spaces. When the city hired a contractor to take over parking management, starting in the upscale Polanco district, franeleros protested. They reportedly marched through the neighborhood carrying signs bearing messages such as, "The streets are not for sale," and "A parking meter doesn't take care of your car." Providing funds for the spare parts needed by buses in the city. Many buses were unreliable and badly maintained which adds to air pollution. 5% of Mexico city’s residents have swapped from using private vehicles to using public transport. Introducing bigger, more efficient articulated buses along four routes to speed commuting and reduce pollution The metro • http://www.bbc.co.uk/news/10302626 Reduces car use in the city Is quick, cheap and clean Doesn’t add to the size of the city as the stations are undergound- more space for green above ground In summer, the extreme heat is debilitating and dangerous for people using the underground. Expensive to extend Machinery is expensive to fix and upgrade Trying to solve the waste disposal problem Mexico City has introduced various measures to tackle the waste disposal problem, including: 1. Encouraging more recycling 2. Building a new plant to burn some waste to generate electricity 3. Encouraging more composting 4. Burying it in new landfill sites. improvement scheme Reducing private vehicles Improving public transport- buses and metro Increasing bike use Solving the waste problem Solving the water pollution problem advantages disadvantages Curitiba, Brazil– a role model for a greener urban future???? https://www.youtube.com/watch?v=eeAZsmpt7a8 Watch the video, as you do jot down notes about what makes the city SUSTAINABLE Now read the information sheet and answer the following questions about Curitiba 1) What makes Curitiba's transport system so SUSTAINABLE? 2) How does this mean a good quality of life for Curitiba’s residents? 3) Why do you think some people call Curitiba a model city?