hello there geographers and welcome back to the Mr sin Channel today we are going to review challenges of urban sustainability now this is our last topic review video but it's not the end of unit 6. don't forget when you are done with this video head on over to my ultimate review packet and check out the unit 6 summary video which summarizes all of the important Concepts that you need to know for this unit if you haven't checked out my ultimate review packet yet you need to take a look at it in it you'll find exclusive videos study guides practice tests and quizzes important vocab extra practice problems and scenarios for each unit documents that not only break down each answer for the quizzes but also explain why the answers are what they are and much more I know I talk about the packet all the time but it is a great resource and is one of the best ways to study not only for your AP human geography class but the national exam as well so the last time we focused on sustainability was in our unit 6 topic 8 video remember there are a variety of different definitions for what it means for a society to be sustainable but pretty much comes down to can a society meet the wants and needs of today's people without preventing future Generations from being able to meet their wants and needs as well as urban areas continue to grow and expand they tend to expand outwards leading to urban sprawl which destroys the surrounding Countryside increases the amount of money being spent on infrastructure and public services and increases the fact of de facto segregation a suburban sprawl occurs it decreases the sustainability of an urban area as urban areas expand the amount of Roads Public Services utilities and other infrastructure needs increase all of which are expensive to build and maintain forcing governments to take on more debt raise taxes and put more burdens on businesses and residents in the area environmentally speaking we can see urban sprawl destroy arable land and the surrounding Countryside as land is transformed and rezoned for urban and Suburban life sprawl also increases the amount of air pollution as individuals now rely more on automobiles to move between different places and are less likely to walk between different locations another impact that sprawl has on an urban area is it increases its ecological footprint a city's ecological footprint is the amount of land and resources that are used to support the population of a city this includes both the land where the city is located and the resources used to support the city and its residents the larger the ecological footprint the more likely it is that the city will start to put strain on the natural resources cities with more urban sprawl and a larger ecological footprint are more likely to contribute more to greenhouse gas emissions since these cities will have longer commute times with more personal vehicles and consume more resources As Cities expand they often end up decreasing the amount of biodiversity in the area this is due to the destruction of local habitats as the urban environment expands into land that was previously uninhabited speaking of the environment we can also see Urban sustainability be impacted by changes in the climate climate change has created new challenges for urban areas such as impacting local electrical grid As Cities face more intense temperature changes such as heat waves the cities see increased energy demands as residents in the area turn on their air conditioning this can lead to Rolling blackouts and high energy costs we saw this happen in September in 2022 when California saw record highs which strained their electrical grid which caused the state to impose its highest level of energy emergency on the state which just felt shy of forcing mandatory rolling blackouts we can also look at the other side of extreme weather and see the impact that freezing temperatures can have on a city such was the case in Texas in 2021 when a polar vortex caused the power grid to fail due to increased demand resulting in the deaths of over 246 people over time as urban areas grow and change they not only see increased energy demands which create new challenges but also see increased flushes more people means more poop and more poop means increased Demand on local sewage system which if cities are experiencing rapid urbanization can be difficult to build fast enough cities that struggle to provide sewage services for all parts of the city risk health concerns with their populations and risk local water sources becoming contaminated other sanitation concerns can occur in cities that do not have proper trash collection have informal settlements and slums or have high density areas with high poverty rates and little investment in essential infrastructure such as water sewage hospitals and education poor sanitation and inadequate infrastructure can create major challenges for different urban areas as we saw in 2010 when a United Nations base in Haiti caused a cholera outbreak which resulted in the deaths of thousands of people a panel of experts appointed by the United Nations found that the strain of Cholera that popped up in Haiti was a perfect match for a strain found in Nepal Nepalese peacemakers were staying at the U.N camp and poor sanitation sent sewage from the camp into local waterways now we can see cities respond to these challenges in a variety of different ways cities can reduce urban sprawl by using smart growth policies creating green belts and implementing growth boundaries which end up restricting the expansions of City's ecological footprint and prevent urban sprawl Urban growth boundaries often encourage infill development which is when a city seeks to promote the development of vacant or underdeveloped land within an already developed area this can take the form of developing new buildings on vacant lot converting older buildings for New Uses or redeveloping Brownfield sites which is when land that was contaminated by previous industrial or commercial use such as land that was being used as a former landfill or gas station is cleaned up and repurposed for new use typically the contaminated land remains empty and vacant until the city can work to redevelop the area and use it in new ways we can look at Hunter Point Shipyard in San Francisco as an example of a city trying to redevelop a Brownfield this Shipyard was originally used as a navy base and was contaminated with Industrial Waste and radioactive material in 2000 proposition P was passed which had the Navy start cleaning up the shipyard and as of 2022 parts of the shipyard are still being cleaned up however the area has been zoned for mixed-use development and in the future the goal is to have a Vibrant Community in the area and I also mentioned Urban growth boundaries and if we're looking for an example of an urban growth boundary we can look no further than Portland Oregon Portland's growth boundary has had a variety of different impacts on the city we've seen an increase in population density air quality the use of bicycles public transportation and a reduction in urban sprawl but by implementing a growth boundary the city has also now experienced issues with the price of housing which has caused some people to struggle to afford living in the city cities that are looking to protect the countryside in Farmland around an urban area can also pass Farmland protection policy which focus on preserving agricultural land this can be accomplished by zoning land for agricultural use only or by government or conservation organizations purchasing the rights to certain land to make sure that they cannot be developed so we can see that cities around the world face a variety of challenges when it comes to Urban sustainability but when cities work together with other Regional governments organizations and other stakeholders they can minimize the impact of these challenges and create more vibrant thriving communities all right geographers now comes the time to practice what we have learned when you are done don't forget to head on over to my ultimate review packet to watch the summary video which goes over everything you need to know about unit 6. plus you can take the practice quiz and the other review materials to help you out not only with your class but that National exam as well as always I'm Mr sin thank you so much for watching and I'll see you next time online