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Green Roof Tops Cool our Cities Down by Paul Rivers for ClimateYou

New York City, like other urban areas worldwide, struggle with the urban heat island effect (UHI). This phenomenon takes advantage of the energy absorption by building materials and results in a warmer environment in city areas compared to surrounding rural districts. This problem fundamentally lies in the physical characteristics of city building materials which are made to hold in heat and makes the outside areas of buildings warmer.  Hotter conditions makes for more  heat related health risks. However, these deleterious health conditions can be avoided by covering rooftops with living plants and vegetation, lessening the effects of UHI significantly. These green roofs, as they are commonly known, have proven to cool down cities while providing significant reduction in air pollution, and offer evaporative cooling, and even economic benefits.

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The US Postal Service has a huge green roof on top of their Morgan mail processing facility in NYC  http://wirednewyork.com/forum/showthread.php?t=6963

First of all, what are green roofs and how are they made?

Hanson & Schmidt, authors affiliated with the Brooklyn Botanical Garden, found that greenroofs were most commonly layered vegetative systems, with clearly outlined designs and types. Two of the basic systems they identified are either extensive or intensive: extensive is a system in which soil reaches a depth of 2-6 inches, weighs 10-45 pounds / square foot, and costs roughly $20-$25 / square foot. Plants grown on extensive systems are generally limited to Sedum varieties, which are drought tolerant, ground covering plants. Extensive roofing systems are shallower than intensive ones and only support small size plant varieties, but provide thermal benefits at the cheapest price. Intensive systems are deeper at up to two feet in depth, heavier at 45-200 pounds / square foot, require high-load bearing roof capacities, and are more expensive at $30> / square foot. While more expensive, these systems can support larger plants, and a wider variety of vegetation. With the specifications these authors provide, it should be easier for residential, commercial, or governmental customers to pick the green roof that best suits their needs.

Green roofs can mitigate air pollution in urban environments directly though their plant layer, and indirectly by reducing the need for electric utilities. According to Vijayaraghavan, a researcher at the Indian Institute of Technology Madras, plants can directly consume gaseous pollutants through their stomata. Green roofs also reduce the underlying issue of power plant emissions. By reducing the need for building cooling systems like A/C, green roofs lower energy needs. Besides lowering electricity bills for consumers, green roofs lessen the power needs from utilities, and corresponding emissions for electricity production plants. This can yield economic benefits in air pollution and health costs. Researchers affiliated with the University of Michigan provide an economic measure of these benefits, specifically looking at pollutants like nitrous oxides. They reference a study by the U.S Environmental Protection Agency (EPA) and Office of Air and Radiation, which used a metric of premature deaths from chronic bronchitis in the Eastern United States to quantify reductions in air pollution. They found that fewer cases of chronic bronchitis translated into an economic benefit between $1680 and $6380 adjusted for 2006 dollars. As well, the researchers calculated that green roofs provide an annual NO­­X (nitrous oxide) uptake benefit of $895 – $3392 for a 2000 square foot vegetated area. Quantifying air pollution benefits in this way allows the interested consumer to easily connect investment information and potential health benefits.

By investigating the environmental, health, and economic benefits of greenroofs citizens concerned about rising temperatures can begin to address the impacts of UHI and request informed changes from local governance.

 
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OUR TAKE: Coming up are deadly heat waves by 2100

Researchers at the University of Hawaii at Kona wanted to study the likely impact of heatwaves as global warming continues. A post by Salon.com reports that researchers discovered that there was no good database, so they made one. They read through 30,000 studies published since 1980. They found 800 deadly heat events in 164 cities in 36 countries. What turns a heat wave into a deadly event? Several things: temperature, humidity, and level of development. While high temperatures can kill by themselves, lower temperatures coupled with high humidity is even more deadly, because the body’s cooling mechanism shuts down when sweat doesn’t evaporate.

The context of a heatwave is important too, in terms of access to plentiful water, air conditioning, and competent medical care. In part because of these contextual factors, less developed countries had more fatalities from heatwaves than did developed countries. Developing countries were also more vulnerable because many, being tropical, had smaller margins of resilience given their normally higher levels of humidity and temperatures.

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2016 United States Heat Wave Map

Based on their findings, the researchers predict that, if the world meets the Paris Agreement target limit of 2°C rise in temperature, fully half of the world’s population will be at risk of death by heatwave by 2100. Should that mark be missed, 3/4 could be at risk. Los Angeles would face 30 days each summer over the heat/humidity threshold; in New York, 50 days per summer; in Houston and Orlando, all summer long. You can clearly see the increase in deadly heat days for various cities at this interactive map.

But that’s way in the future, right, so why worry?  But consider this: just a few days ago Phoenix saw an all-time record high temperature for that city of 119°F; the same is happening throughout the Southwest where weather experts have issued heatwave warnings that are “hazardous and excessive.”

Think about it, then call Washington.

 
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OUR TAKE: Getting Warmer & Why

This important article starts off arcane — reporting on a study of stalagmites in a Russian cave — and ends with an apocalyptic warning — we’re heating the climate 20 to 50 times faster than ever before. The study helps to resolve a disparity — the article calls it a conundrum — between computer models of past climate change and data analyses for the same period. We tend to trust data and distrust simulations but the study showed that with better data, the analysis supported the simulation. Ice ages happen because the earth’s orbit is elliptical. During ice ages, when the earth is relatively far from the sun, winters are colder, summers cooler. As the earth in its orbit gets closer to the sun, summers get warmer, winters less cold, glaciers melt and retreat, and the ice age ends. This last happened over the period 15-10,000 years ago. About 7,000 years ago, that trend stabilized and earth began a long, slow warming trend. Since then, the earth has warmed about 0.5°C. During that time, humans adopted agriculture, created civilizations, multiplied, and prospered. GISS Global surface temperature Data

However, about 200 years ago, we began the Industrial Revolution, burning large quantities of fossil fuels, and emitting greenhouse gases which accelerated the slow warming trend. It took only 170 years to double the temperature rise of the previous 7000. In the last 40 years, thanks to growing population and prosperity, we are increasing the temperature by 20 times. If we miss the Paris Agreement target of limiting the global rise to 2°C, we could experience a heat rise rate 50 times faster than ever before. Catastrophe looms.

 
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Predicting future Hurricanes by City-Tech Blogger Branden Harris

People are still mourning the loss of lives of families and friends that were tragically killed in last year’s East Coast hurricane, Matthew. This occurrence left not only trauma, but $10 billion in damages in the United States alone. Having said that, the coastal areas are once again preparing for another hurricane season. hurricane outlook

Credit: NOAA

Forecasters from the National Oceanic and Atmospheric Administration predicted for 11-17 storms to form of which “five to nine are expected to become hurricanes, and two to four major hurricanes. Unfortunately, there is no telling when, where, and how the storms might hit.

 

 

 

 

 
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Our Take: Making Climate Science Less Boring & More Emotional

This opinion piece out of Australia, is all about communication. The scientists have been hammering their message that climate change is real, it’s a clear and present danger, and, yes, we’ve caused most of it ourselves by burning fossil fuels in our cars, factories, and power plants. However, the scientists’ facts, figures, graphs, and consensus touting have mostly fallen on deaf ears. Climate boredom is rampant. What’s lacking is emotion.

cliscie commun

(Imperial College of London)

The facts need to be tied to human concerns. To project climate trends to 2100 causes MEGO (My Eyes Glaze Over) in most people. Some savvy scientists have added human timelines to the projections — your lifetime, your kids’, your grand-kids’. That connects. A light goes on. Understanding dawns. Now, let’s converse.

 

 

 
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