American Planning in the Next Essay
- Length: 11 pages
- Sources: 5
- Subject: Weather
- Type: Essay
- Paper: #88334151
Excerpt from Essay :
The state has really took out half of the $300 million cost that it took to build the Hudson River Park (150 acres land/400 acres open water) with yearly assumptions that are around $20 million to $25 million. 20 years from now it might be a hard challenge keeping this up with the anticipated climate change.
Climate Change: Precipitation
The third reason why climate change will be affecting America in the next 20 years is because of the local precipitation. In addition to impacts on temperature and wind, the urban heat island affects local precipitation patterns. Both comparatively warmer air and higher attentions of particulates over the cities that can cause little more frequent rain events (Ahrens 2006).
About 20 years from now, this will become an issue because the Human-made modifications of the natural environment are affecting the thermal stratification of the atmosphere that is located above a city and also as the local heat stability and hydrologic series (Spronken-Smith). This will be a big issue 20 years from now because the urban heat island effect is going to cause the warmer air (counting its higher attentions of pollutants and moisture) to start increasing more freely than cooler air over the areas that are non-urban (Oke 1987). Consequently, moisture and contaminants are taken into levels that are much higher of the urban air. Therefore, the urban heat island is creating air that is warmer and damper over the city. Once this is lifted, the air will normally cool and, if there is enough moisture available, precipitation and clouds may start to form. The improved amount of cloud concentration nuclei (CCN) and ice starting nuclei (in) from urban contamination further improves urban rain.
Qing Lu Lin and Robert Bornstein, meteorologists from San Jose State University, have been using data from meteorological stations that were being set up all through the 1996 Summer Olympics and discovered that the urban heat island that was in Atlanta shaped up some frequent thunderstorms (Ahrens). By means of the National Weather Service's ground-based meter to gather statistics (the same tool that is being utilized to predict weather for Olympic athletic events), Lin and Bornstein discovered that five of nine days of rain over Atlanta were produced by the urban heat island effect (Lin and Bornstein 2000).
Increased thunderstorm incidence over cities has mixed blessings. On the other hand, precipitation does to a job of cleaning the atmosphere of contaminants and cools the air over a city. Nevertheless, the enlarged precipitation over an area of typically impervious protection can then cause a much greater probability of urban flooding. A lot more rain that is over urban districts can strain previously taxed urban storm water management systems.
Roughly, 2o years from now, urban parks will possibly be reducing the precipitation irregularities of the urban heat island by keeping the air cool above cities and eliminating particulates that could possibly become concentration nuclei. Urban parks are also providing the cooling influence of additional precipitation that is without the detrimental impact of storm water flooding. Around 20 years from now and by providing a lot more parks, cities could possibly better managed by precipitation pattern changes.
About 20 years from now cities will become key contributors to both low-level atmospheric pollution and bigger climate change because of greenhouse gases for instance carbon dioxide. Both consequences could possibly have an opposing influence that is on urban populations. When it is 20 years from now, urban air pollution from vehicles will be more particularly harmful, which will result in more respiratory difficulties, acid rain, and decrease in the quantity of solar radiation that will be able to reach the earth's surface. Happily, research is showing vegetation can actually act as a pollutant sink.
With the climate changing 20 years from now, high levels of carbon dioxide (CO2) and other gases will trap heat from the Earth in the atmosphere and forbid it from discharging heat into space, a marvel that is known as the "greenhouse effect." Trees get rid of (sequester) CO2 from the air during photosynthesis and bring back oxygen to the atmosphere as a result. Trees for that reason normally act as a carbon sink and oxygen source (Spronken-Smith).
Project Evergreen will something hopeful to use 20 years from now because it is supported by studies showing that inside one year an acre of trees can absorb enough carbon dioxide to equal the amount produced by driving a car 11,000 miles (Virginia Cooperative Extension, www.ext.vt.edu). At the same time, trees and turf in a park also return significant amounts of oxygen to the atmosphere. A turf area of only 50 square feet produces enough oxygen to meet the needs of a family of four (www.projectevergreen.com).
In addition to carbon, studies have also shown how effectively trees remove other pollutants. A 212,000-acre urban park tree cover removed 48 pounds of particulates, 9 pounds of nitrogen dioxide, 6 pounds of sulfur dioxide, 2 pounds carbon monoxide, and 100 pounds of carbon daily (Coder 1996).The U.S. Forest Service calculates that over a 50-year lifetime one tree generates $31,250 worth of oxygen and provides $62,000 worth of air pollution control (www.coloradotrees.org/). Yet another study found trees in New York City removed an estimated 1,821 metric tons of air pollution in 1994 (Nowak 1995).
Increasing the amount and size of well-vegetated parks can help reduce the amount of pollutants in the atmosphere. In addition to the obvious health benefits for humans, the pollutant-reducing capabilities of vegetation also bode well for climate change management, particularly with respect to the greenhouse effect.
Climate Issue: The Death of Trees
Trees in western North America are dying at a very faster and faster rate, and climate change 20 years from now is even more likely to blame as time goes on. The rising deaths could basically alter Western forests for the reason that tree reproduction has not really increased to offset fatalities, according to a new studies that are being published daily Science. New seedlings are not rising rapidly enough to fill the holes.
"If present trends endure, forests will become sparser 20-year from now," co-author Philip van Mantgem, an ecologist that is with the U.S. Geological Survey, mentioned in a press conference call. If this happens, this would be a future setback in the fight that is going against global warming because forests that are thinner with small, young trees store less carbon, so more heat-trapping carbon dioxide would cycle into the atmosphere.
A large-scale transition to such threadbare woods would have other negative effects as well, van Mantgem said. Species that depend on big stands of old growth, such as marbled murrelets and spotted owls would have much less room to roam. And the risk of catastrophic fires would go up with more dead, dry wood lying around to fuel them.
The evidence is mounting that warming and drought are changing ecosystems across western North America. Other studies have documented major tree die-offs and surging wildfires. Plant species have climbed uphill, and bark beetles are laying waste to ever-increasing tracts of woodland. The new study "ads to the list," said Michael Goulden, an ecologist at the University of California, Irvine who was not involved in the research. "Something large and important is happening to Western ecosystems, in correlation with climatic shifts."
The research revealed that tree mortality rates in old-growth forests from southern British Columbia to Arizona have doubled every few decades over the past 50 years. This is likely because the region has warmed considerably during this period too, the scientists say. Since the 1970s, temperatures across the West have risen by 0.5-0.9 degrees Fahrenheit every ten years. Such warming has led to reduced snowfall, a smaller winter snowpack, and earlier spring melts.
"Trees are under more drought stress," said USGS ecologist Nathan Stephenson, a co-author on the study.
Higher temperatures could also be killing trees by jump-starting their enemies, he said. The warmer the weather, the faster the insects (such as bark beetles) and pathogens that feed on trees can grow and reproduce. And the two factors could be acting in concert, as drought-stressed trees are less able to fight off disease and predators.
The scientists looked at 76 forest plots across western North America. All were old-growth stands, undisturbed for at least 200 years and censured multiple times from 1955 to 2007. The researchers found that tree death rates increased in 87% of plots during this time. This strong pattern held no matter how they parsed the data -- across all regions, elevations, tree sizes, and tree species.
Altered burning regimes aren't the answer, they argue, because tree deaths have gone up even in forests where fire has never played a major role. Pollution or forest fragmentation cannot be responsible, either, because the mortality rate has risen even in pristine habitats. That leaves climate change as the most likely culprit.
"Even in the most resilient old-growth stands,…