White roofs for cooler homes

In developing countries an unpainted tin roof keeps the rain and sun off of hundreds of millions of people. But as it turns out, simply painting the roof white could vastly improve the ability of the roof to reduce heat in the home. In many places like India, Africa, and Latin America temperatures soar into the 110s but many people do not have air conditioning, so this is a serious health issue.

Choosing roofing materials to reduce heat involves both albedo and emissivity.

Albedo = reflectivity of a surface. Measured on a scale from 1 to 100%
High albedo = a mirror or white surface
Low albedo = a dark asphalt street

Emissivity = ability of material to release/emit stored heat back into the atmosphere thus cooling the building down. Measured on a scale from 0 to 1 with higher number meaning heat released faster. Emissivity really comes into play more in sunny, warmer climates.

So of the total incoming solar energy
a. on one hand albedo prevents some heat from ever being absorbed into the material in the first place while
b. of the heat that is absorbed, emissivity is how fast that heat is then released.

So for a good roofing material ideally both albedo and emissivity would be high.
This site also mentions that white metal roofing is the best material for warmer climates. It has a fairly high albedo of 66% due to the color but also a super high emissivity of .83.
http://home.howstuffworks.com/home-improvement/construction/green/10-best-roofing-materials.htm#page=10

By stark contrast, an unpainted tin roofs like the ones found all over the developing world drops down to an emissivity of .08.
http://www.coolmetalroofing.org/content/faq/faqs.cfm?FAQCatId=1

So just painting a tin roof white both completely reverses the emissivity and also increases the albedo, cooling houses down.

There is even an organization called the White Roof Project.
http://www.whiteroofproject.org/faq
http://enduse.lbl.gov/Projects/ESRoof-Tab4.pdf

What if these were all painted white? Tin roofs in San Jose, Costa Rica.



In New York City the CoolRoofs initiative has painted 6,000,400 square feet already at the time of writing.
http://www.nyc.gov/html/coolroofs/html/home/home.shtml


Green roofs in big cities bring relief from above - NY times
http://opinionator.blogs.nytimes.com/2012/05/23/in-urban-jungles-green-roofs-bring-relief-from-above/?_r=0

Rio urban environment: Olympics ready?

Metro issues
I was recently riding the metro system in Rio de Janeiro. During rush hour, there were so many people packed into the cars that I had to let two trains come and go before I finally got on. Trains were showing up already packed, only a few new passengers could fit--and I definitely tried. Then when I got off, in the trample of bodies a lady got hurt, looked like she sprained an ankle. She was carried off by two people. In Rio people don't wait until passengers get off first before boarding, each stop is a melee.

I guess they can just add more subway cars before the Olympics? If not it could be a real problem--or a jackpot for Rio taxi drivers.

Add to that the fact that the new subway line designed to go to the Olympic Park is at "high risk" of not being built in time.

Key Rio Olympics Subway Line at ‘High Risk’ of Being Late
http://www.bloomberg.com/news/articles/2015-07-07/key-rio-olympics-subway-line-at-high-risk-of-being-late

These are only a few of the problems I noticed in Rio.

Rio smells, big time. At first I thought it was the stench from urine of thousands of drunk and homeless people but apparently there are literally tons of dead fish showing up in Rio's waterways.

-50 tons of dead fish in the lagoon that lies at the heart of Rio, Lagoa Rodrigo de Freitas (see map). They plan to hold canoeing rowing events in this lagoon!

-56 tons of dead fish in Guanabara Bay, the main water body that flanks Rio. On a taxi ride to the airport along the coast of this bay, it absolutely reeked the whole way.

Sad And Smelly: Massive Fish Die-Off At Rio's 2016 Olympic Site
http://www.npr.org/2015/04/21/401167059/sad-and-smelly-massive-fish-die-off-at-rio-s-2016-olympic-site

Rio also has crime issues, big time. Case in point: Last Friday, my last night in Rio, around 10 pm I went two blocks outside my airbnb apartment near the Sambadrome and Central Station to get an ice cream from a little hole-in-the-wall store. Lots of people are on the street drinking at the bars, kids even kicking a soccer ball at 10 pm. As I'm just reaching the store in the middle of the block, I hear a huge bang like a shot fired just around the corner where I had just walked from the apartment. First I think it's a gunshot, then I think, "well maybe somebody's tire just popped." Nope. The residents knew better, they all ran inside and I followed. Within seconds a police car pulls up 50 meters away at the end of the block, the door swings open and an officer's arm comes out "bang bang!" two shots fired. The car revs and turns left, heading away from me and continues the chase, where it stopped at the far end and looked like they apprehended someone.

On the airplane coming home from Rio, I sat next to a young guy who works for Ronald McDonald House in Rio headed to the Ronald McDonald Foundation Convention in Chicago. He said he used to live in an apartment where a gunshot went through his window and the cops, after measuring, said it came from a gunfight in a a favela (slum) nearly a kilometer away. He said he had to move to another area.

Much of Rio is simply not safe.

In addition, Rio has a huge number of homeless people, over 5500, which is unmistakably clear to anyone visiting the city.
http://vivario.org.br/en/more-than-5-thousand-homeless-people-in-rio-de-janeiro/

And add that a few weeks ago on Sunday, August 16, 2015 hundreds of thousands protested jointly against corruption in the Rousseff government in 200 major cities in every one of Brazil's 26 states.
http://www.theguardian.com/world/2015/aug/16/brazilians-protest-pressure-builds-on-dilma-rousseff

These are serious challenges, it should be an interesting Olympics.

8500 refugees living in Brazil

Heard on a TV news report in Brazil that there are now 8500 refugees in Brazil, the largest groups from Syria, Colombia, and Angola (fellow Portuguese-speaking nation).

Brazil was the first South American country to take in Syrian refugees and now Argentina has followed suit.

Syrians now the largest refugee group in Brazil
http://www.pbs.org/newshour/rundown/syrians-now-largest-refugee-group-brazil/

The refugees will continue to arrive because Syria is will remain FUBAR for a long while to come. As has been said by Fareed Zakaria, the US strategy of "supporting moderate rebels" in Syria simply won't work because in this war there are no moderates. You have terrorist rebels like Al Quaeda and ISIS against the terrorist Assad government which has used chemical weapons against its own people. The Kurds are the group the US should be arming--they are fighting ISIS for the Western world--yet we have left them out to dry.
On this map from Wikipedia you can see no less than five different groups holding territory in Syria.


https://en.wikipedia.org/wiki/List_of_armed_groups_in_the_Syrian_Civil_War#/media/File:Syrian_civil_war.png