Rain Water Harvesting (Part 2)

Domestic Uses

Helmreich and Horn Recommendations
The collection area's Helmreich and Horn recommended for domestic rainwater harvesting (RWH) include roofs, courtyards, and roads. GIS was predicted to be a useful tool in locating appropriate collection zones.

The most important aspect of the storage container is a tight lid that prevents contamination, algae growth, and mosquito breeding. They didn't have a definite recommendation for the location of the tank, above or below ground, nor the size of the container. Larger tanks were not inherently preferable as it took longer to cycle through water, so it's less fresh.

If drinking water is the aim of the harvesting, then open containers were not recommended. And collection sites in urban areas would need to filter out the air pollutants and roof contaminants.

Implementation Example
Bangladesh is looking toward rainwater harvesting as a potential solution to reduce urban flooding during the monsoon seasons and alleviate water shortages in the dry season. A study was conducted by Akter and Ahmed to access the potential for rooftop RWH in South Agrabad (southwest part of Chittagong city). They were able to demonstrate the value of GIS in analysing sites' suitability  for  RWH, as Helmreich and Horn predicted.  Factors considered in their model include the area of the roofs, the slope of the land, how easily runoff could flow, and the amount of drainage. (Elevation changes in the land was a factor that Hornreich and Horn emphasis for agriculture but not domestic collection.) South Agrabad was divided into 16 watersheds. Watershed one is lauded with rooftops being able to absorb .44 meters out of the 1.71 meters of total rainfall. Therefore Akter and Ahmed say that roof top rain harvesting can alleviate up to 26% percent of the flooding depth.

The possible amount of rainwater that could be collected in
each watershed compared to the current amount of runoff
in South Agrabad. Source: Akter and Ahmed

The 31% collection of total runoff in Watershed 10 was not considered a satisfactory reduction of water because the amount of stagnant water would still be above rickshaw height. The cause of additional flooding may be due to Watershed 10 being the lowest slope in the region. Excess runoff from other areas may accumulate there.

The amount of water each person could receive from roof water harvesting was calculated for 2006 (a dry year), 2011 (an average year), and 2014 (a wet year). They found that the daily amount provided by these collections was 20 liters per person.

Rain Water Harvesting Takeaways

The theme for both Africa and Bangladesh was using RWH to alleviate drought while reducing flooding. The principle applied to both agricultural and domestic water use. Helmreich and Horn briefly mention intense rainstorms, but they never delve into the benefits that water collection could have on reducing flooding risks.

It is interesting that Maswa, Tanzania used roads as a collection point, when Helmreich and Horn recommended it for domestic purposes. While the urban environment has more roads, they are a prominent feature of rural landscapes. It makes sense to take advantage of a surface material that causes runoff, which Helmrich and Horn see as a fundamental first step in RWH. Another reversal of recommendation occurred with South Agrabad, Bangladesh's use of land slope in their consideration of RWH sites. This might not have been considered a factor for Akter and Ahmed as they didn't consider any benefits inlvoving flood reduction.

Rain Water Havesting (Part 1)

The benefits of Rain Water Harvesting are not just in preventing runoff, as was mentioned in my World Soil Day post. It is also an important tool for softening the effects of drought.
Helmreich and Horn examined the potential for rain water harvesting (RWH) for both agricultural and domestic uses. This post will examine their findings with respect to agriculture and see an example of agricultural RWH. Next post will examine domestic RHW and compare it to the methods used in agriculture.

Agricultural Uses

Helmreich and Horn Recommendations
The two types of agricultural RWH mentioned by Helmreich and Horn were (1) water stored in the soil where it fell and (2) water collected away from the farm and stored away from the crops.
The initial requirement for a good collection site is a surface material that allows runoff. Additionally the slope of the land must be great enough to cause the runoff to flow.
The collection point could be above, below, or within the ground. Underground was recommend over above-ground structures as it prevents evaporation. If the water was to be stored within the ground itself, then the soil must retain water well.
It was recommended that local labour and materials were used to assess areas to adapt and build the necessary infrastructure.

Implementation Example

Maswa, Tanzania is a semi-arid region where a lack of rain can prevent crop growth and trap farmers in poverty. The crops may miss out on the benefits of up to 80% of rain, because they can't absorb it fast enough. RWH allows farmers to replace low-profit, drought resistant crops, such as Sorghum (a cereal), with high-profit, thirsty crops, like rice and vegetables. A study by Hatibu et al. looks at the economic benefits of different times of RWH systems. The examined Microcatments, Macrocatchments, Macro catchments paired with road drainage, and Macro and Microcatchments paired with pond storage. These RWH were mainly made local labor and materials (lots of earth ditches) as recommended by Helmreich and Horn. While the roads are not locally funded, the RWH systems branching off from them are locally constructed.

Really quick term definitions:

Typical microcatchment set-up. Source: Ali et al.

Microcatchments- small enhancements in the topography (eg. trenches) to increase the amount of water going to plants; Type 1 of Helmreich and Horn, which they highlight as cheap and local

 

Due to the lack of other jobs, economic benefit
(in US$) is best measured with respect to land
area. Source: Hatibu et al.

Macrocatchments- similar principles as microcatchment but for diverting large pools of water that accumulate during storms; Type 2 collection with Type 1 storage of Helmreich and Horn

Marcocatchments paired with road drainage- this diverts the pre-existing large catchment of water (used to prevent flash floods on roads) to crops; Type 2 collection with Type 1 storage of Helmreich and Horn

Macro and Microcatchments paired with pond storage- allows farmer to store water away from the crops and water them when needed; Type 2 of Helmreich and Horn


Hatibu et al. found that that Marcocatchments paired with road drainage was the most profitable in terms of US$ per hectare (land area).  This finding exemplifies the dual benefit of flood and drought alleviation that RWH can provide. The pond storage might be improved by the underwater storage recommend by Helmreich and Horn. The pond's higher potential for evaporation may be way it is so much less efficient than the road drainage.

Adaptation in COP

An agreement was reached at the end of the two-week negotiation. Source: Reuters

COP21 has drawn to a close. The broad impacts have been well reported, so I will examine how the COP agreement will affect adaptation.


The proposed actions to be taken before the agreement is enacted in 2020 include:

• Developed countries will create a solid plan to raise USD 100 billion for mitigation and adaptation that will begin in 2020, including an increased budget for adaptation (Paragraph 115)
• 2016-2020 will be a test period for adaptation technologies that increase resiliency, decrease vulnerability, and help enact adaptation (P125, 126,128)
• This will be a cooperative action that will examine what has worked in the past and offer specific solutions for the future (P128,129,130)
• A user-friendly online report will be summited annually (P130)

I think the test period for 2016-2020 is incredibly exciting. I'm glad that they will be reporting their result online in such a way that local government can support their adaptation.


The actual agreement included Article 7 that was all about adaptation. The highlights of this section include:

• Increasing resiliency, decreasing vulnerabilities while still developing in a sustainable manner (Paragraph 1)
• Focusing addition on those who are most vulnerable (P2)
• Decreasing emissions as a way to minimize future adaptations (P4)
• Recognizing that adaptation needs to be implemented in a 'gender-responsive' manner (P5)
• Using both scientific and traditional knowledge to create the best local strategies (P5)
• Sharing information on what has worked in the past, increasing scientific knowledge, and offering specific solutions for the future (P7)

I thought this was a very comprehensive plan for adaptation. I love that it is so closely tied to development, which is exemplified by their nod to adaptation that does not perpetuate forms of gender discrimination. I also appreciate the balance of scientific and traditional knowledge as locals will know the subtleties of their local environment.

Com'on Congress

Reactions from the COP21 climate conference are already popping up in the news. All eyes are on China and the US, the two top contributors of CO₂. The BBC recently praised China on their increase in renewable energy. As for the US.... The house has decided to pass legislation that would block the EPA's cap on coal emissions. It should be noted that 63% of the US population supports cutting emissions at coal powerplants.

House Speaker Paul Ryan sending a message
of dissent to Paris. Source: Yahoo!News

The Republicans held the vote on the SAME day as Obama's speech at COP21. They wanted to demonstrate their opposition, to any pro-climate remarks he made. The House Speaker Paul Ryan claims the benefits from any legally blinding agreement will not offset the high costs. It's beyond me why anyone would deliberately undermine their country's chance to demonstrate global leadership. Why should any other country, especially the developing ones, commit to cutting their emissions if we are unwill to cut ours?

Happy World Soil Day!

Today, December 5th, is World Soil Day!  Who knew?

One way to celebrate is to reduce runoff around your home. Run off and flooding can wreck havoc on topsoil. Limiting impermeable ground, making rain gardens, and harvesting rain with rain barrels are possible solutions to reduce runoff.

Keep fertile soil where it belongs. Source: GoSmith

Let it sink in: The inner workings of porous concrete

Permeable pavements, including porous concrete, are one of the solutions mentioned in the London Sustainable Drainage Action Plan. They are filled with little openings that allow rainwater to seep through to the soil. This should help reduce flooding. However, intentionally riddling a building material with holes is bound to produce some challenges. Engineers must balance how much water is allowed to flow through (conductivity) with the strength of the material.

How Porosity Affects Conductivity

The non-linear relationship between porosity and conductivity.
Source: Montes and Haselbach

Montes and Haselbach related the amount of holes in concrete (porosity) and conductivity. They used 17 samples of three different concretes to examine different porosities. Porosity was measured by comparing the weight of the concrete when it was dry to when it had been submerged in water for 30 minutes. They used a falling head permeameter to find the conductivity (a video of a similar experiment can be found here). They found a non-linear relationship between conductivity and porosity with a threshold at 15% porosity. Concrete with porosity lower than 15% didn't allow any flow.


Huang et al. used latex, sand, and fibers in concrete mixtures with aggregates (the little rocks in concrete) sizes of 12.5 mm, 9.5 mm, and 4.75 mm. They also used a falling head method to measure conductivity (aka permeability), but they used a vacuum seal to measure porosity.

Mixing concrete with other fillers cuts the permeability. Source: Huang et al.

Montes and Haselbach's curve predicted about a 20-60 mm/s conductivity for the latex, latex and sand, and latex, sand, and fiber mixes. The regular porous concrete should have had a conductivity of 80 mm/s. The actual permeabilities were consistently, considerably lower. The similar conductivities for the 3 add-in mixes shows that porosity should not be the only variable in Montes and Haselbach's relationship (equation on the 1st picture).

Creating Strength Despite The Holes

The fillers added by Huang et al. strengthen the concrete at the expense of a little conductivity. A mixture of latex and sand had both high permeability (compared to other add-ins) and high strength. Although, Huang et al. point out that their fiber wasn't thoroughly mixed.

A latex and sand mixture is both strong and permeable Source: Huang et al.

Yang and Jiang added silica fume (SF) and superplasticizer (SP), organic polymers, to their concrete. They measured a water penetration coefficient, similar to conductivity, to find out how quickly the concrete could absorb 20 mm of water. (They poured 200 mm of water and timed between 160 and 140 mm.) After performing a 28-day compression test, as opposed to Huang et al.'s 7-day test, Yang and Jiang produced an outdoor-cured  SF and SP concrete that had a strength of 58.9 MPa. The water penetration coefficient was only 2.9 mm/s. This demonstrates the potential strength of porous concrete, but the cost of the polymer may make SF and SP an unrealistic add-in. I foresee Huang et al.'s use of cheaper materials will make theirs more applicable, despite its weakness.

Porous concrete can help prevent pavement from becoming a river. Artist: Edgar Müller

Practising What I Preach: November Update

In 'Practising What I Preach' I revealed that my yearly carbon emissions are 9.04 tonnes. I decided to be more mindful of my footprint. I cut back on riding the bus 7-8 times a week to only twice a weeks. I way mindful of where my food was grown and tried to buy British goods. After a month of being aware of my contributions to I have reduced my carbon by... *drumroll*...



Source: Carbon Independent

.18 tonnes!

Oh.

That's not as good as I hoped. The quickest way for me to get those number down is to cut my miscellaneous spending (hygiene, books, phone, etc.) to well below average. With the holidays coming up, I'll need to get creative when gift-giving.

Water Woes: Urban Flooding

"Climate change is a story about water. Too much, too little, at the wrong time." - Jesse Scott

In an earlier post, I mentioned how the frequency of extreme heat and extreme precipitation events will likely be the hallmark of climate change. Recently, I've been talking about the benefit of green roofs and shading on the urban heat island. Now I would like to speak to extreme precipitation.



Flooding in Accra, Ghana this past June left over 150 dead. This number comes 
from both those who drowned and the who died in a petrol station fire that
was offering shelter. Source: Africa News Today

One of the most devastating results of extreme precipitation is the flooding that comes with it. In some developing African countries, floodplains are home to the most vulnerable poor due to the affordability the come with dangerous lands. These floods are not just caused by sea-level rise. Floods that are the result of backed up drainage and pave surfaces are becoming more common. As temperatures rise so does the maximum water vapor content in  the area allowing to heavier rains than previously possible.

Current adaptation strategies in these areas include weighing down possessions with bricks and sitting on the highest dresser with your family until flood levels recede. This is unacceptable in the 21st century. Communities need, at the bare minimum, (improved) drainage systems and waste disposal services, to prevent the drainage from getting backed up. I will not be covering the logistics of hooking these areas up to local disposal services. Instead, I will focus on sustainable drainage systems proposed for London that may help worldwide.

Defforestation vs Afforestation: Conflicting Solutions

A clear difference in albedo between forests and croplands. Source: usagi-hikari9

Difference in surface temperature (^oC) in
 2150 with deforestation at a A)Global,
B)Linear sum of the regional, C)Boreal,
D)Temperate, E)Tropical scale compared
to current projection. Source: Bala et al.

Trees play an important role in the carbon cycle by removing CO₂ from the atmosphere. They have a regional passive cooling effect through evapotranspiration. But their albedo is lower than most other surfaces when it snows causing them to absorb more heat. This is seen an 'effective emission' of radiation because it adds to the Earth's warming. Because these qualities are at odds, both deforestation and afforestation have been proposed options in reducing climate change.

Bala et al. predict a global cooling resulting from deforestation. The used 3D climate and carbon model to simulate large-scale deforestation. The model gives more weight to CO₂ removal than similar models, so Bala et al. expect an even greater cooling than reported. The simulations were latitude based, and forest were allowed to expand in areas not currently deforested. Boreal deforestation (Map C) has the largest cooling effect with minimal increase in CO₂ levels. Tropical deforestation (Map D) causes warming, and temperate deforestation (Map E) causes minimal warming. Both show a substantial increase in CO₂ levels. The global level of net cooling seems to be linearly related to the individual regions (very similar maps for A & B).

Bala et al. do not insist on immediate total deforestation, they recognize the vital role that forests fill outside of climate control. They recommend focusing afforestation projects to the tropics. Temperate and boreal afforestation projects should be met with skepticism.

Montenegro et al.'s assessment showed cooling when there was afforestation at any latitudes. They used satellite data to create a model with 5-25 km resolution. They only looked at converting current cropland, and their albedo difference between forest and cropland was much smaller than other estimates. This showed that benefits from afforestation were not rigidly marked along latitudinal lines. Two graphs, showing the maximum and the minimum cooling as a result of afforestation so highly localized patterns. Russia, surprisingly, shows very high benefits no matter the conditions. Montenegro et al.'s model allows precise evaluation of individual projects.

Difference in net drawdown (kg/m2) for afforestation compared to current
 draw down. Minimum net drawdown conditions maximize albedo difference
between crops and forest and minimize the carbon storage of trees.
Maximum net drawdown conditions minimize albedo difference and
maximize storage. Source: Montenegro et al.

By creating a latitude based analysis Bala et al. fall into the 'wide-brush' trap described by Montenegro et al. There is the possibility that they ended up overestimating the albedo of forests because they accounted for afforestation in unsuitable areas. Montenegro et al.'s minimal conditions align best with Bala et al.'s findings, with the exception of Russia. If Bala et al. were correct concerning linear global scaling, afforestation in Russia should cool the earth despite being in the Boreal zone.



Trees in the Concrete Jungle

Urban trees are providing shade. Source: Abby Yao

I wasn't sure about talking about trees effect on the urban heat island. While planting a tree is easy enough is suburban or rural areas, in a city even a small space hard to find. And depending on your latitude trees might add to the problem because they reflect less light than snow. The planting of trees will be an important piece to the puzzle, and here's why...

Regarding CO2 emissions, trees offer a dual benefit. They take up carbon from the atmosphere by storing carbon in their wood (à la photosynthesis). Even more importantly, they prevent carbon dioxide from entering the atmosphere by keeping buildings cool. In fact, over 3 times more carbon is offset by trees' ability to limit carbon dioxide due to air conditioning than their capacity to store carbon. Much of the cooling comes from shade, but there is also ambient cooling of the atmosphere in an urban forest

Planting trees for shade not the easiest in cities where space is tight. I found one interesting solution by Shubhedu Sharma, tiny forests. I would expect most cooling to come from ambient cooling and not shade. They can help with urban cooling in at latitudes where snow albedo isn't important. However, if you are constrained by space, this project takes up more room than a tree.

At all latitude trees also offer the added benefits of reduced smog, less run-off, increased property values and improved quality of life. Tiny forests also increase biodiversity and may produce food. Reducing run-off will be especially important moving forward because more frequent extreme precipitation is expected.

Shubhendu Sharma's talk on creating tiny forests for the price of an iPod Source: TED.com

Science behind the Potwine Passive House

Source: Alexi Arango

Why does it matter?

A study in 2008 found that around 40% of the energy consumed in the US and the UK was used in our buildings. (If you look worldwide the percentage dropped to 24%, but developing countries are expected to double their contribution in the next 20 years.) Energy consumption currently accounts for 80% of humans' CO₂ contribution.
According to the same 2008 study, US and UK homes use respectively 53% and 62% of their energy on heating and cooling. Respective office buildings put 48% and 55% of their energy towards climate control.



What is passive heating?

Potwine Passive House's shining concrete floor.

Source: Alexi Arango

The concrete floor in Potwine Passive House is its 'thermal mass', a material that takes a long time to heat up and cool down. Heat moves in between the concrete and air so that it's going to the cooler of the two. In other words, when the house gets hot in the afternoon the heat is stored in the cool floor. Voilà, passive air conditioning! And at night when the house cools down, the heat stored in the concrete during the afternoon is released into the air. Ta-dah, passive heating!

Passive heating is a balancing act of evening out the warm and cold daily temperatures. Unfortunately, this means it is not advised for extreme climate temperature. (Averaging a really cold afternoon with a really, really, really cold night just leaves you really, really cold all the time.)

But why bare concrete?

After all, concrete has a lower heat capacity (how hard it is to heat and cool) than wood. The problem lays with wood's inability to conduct heat. It would cause uneven heating.

Rugs are also out. They act as insulation so that the concrete can't heat up during the day.

Potwine Passive House used blown-in fiberglass for insulation
because it was recycled and didn't need to be fireproofed.

Source: Alexi Arango 

How can insulation help?

In Erzurum, Turkey researchers found that they could get an energy savings of 27%  by optimizing insulation in ceilings, walls, and floors. They noted the inverse exponential relationship between insulation thickness and fuel/emissions reduction (i.e. eventually adding more insulation won't help keep your home comfortable). Three years later in Denizli, Turkey optimizing insulations in ceilings, walls, and floors was found to have an energy savings of  46.6% and an emission reduction of 41.53%. This is partially due to windows (which were not insulated) in Erzurum accounting for 47% of heat loss as opposed to Denizli where they only contributed 34.8%. There was no schematic of the insulation at the Erzurum site, so differences in construction technique cannot be analyzed.

While the exact amount of benefits from insulation varies, it will always help keep your home warm during the winter and cool during the increasingly probabilistic heat waves.

A Sneak Peak at Future Housing

Source: Alexi Arango

My parents went on a house tour and Amherst, Massachusetts. They came back raving about the cool the Potwine Passive House! Although, cool may be the wrong word, because even on a crisp New England morning the house was nice and toasty. This was, in part, due to the feature that stuck out to my parents, the flooring.



Source: Alexi Arango

It was a thick concrete slab, not what you'd expect on a home tour. This slab was vital to the heating and cooling of the house. It stored heat throughout the day and slowly realised it at night. In fact, 75% of the house's heating to comes from body heat and solar light. In the summer, the slab would become a heat sink. The combination of flooring and extraordinary insulation in the house keeps it comfortable year round.

This home reduces carbon emission while fluidly adapting the temperature of its environment. As the world heats up, this may be a sustainable solution for a comfortable home temperature.

 

 

COP21 Seminar Takeaways

Source: COP21

Thursday I attended Jesse Scott's talk 'The UN Climate Conference 2015: what is it trying to do and can it succeed?' hosted by UCL Department of Political Science. The UN Climate Conference 2015 also know as COP21 will take place from November 30th to December 11th in Paris, and the 196 governing bodies in attendance are there to ensure climate-related goals are being met. Scott brought both good news and bad news going into the conference.

Bad News: 

Scott mentioned that the emissions being cut would not be enough to stay below 2^oC. Nations are trying to go green while still growing their economy. Additionally, she pointed out that nations, such as the US, are slow to act because they desire national consensus. However, this may backfire because the challenge will be even larger in the future.

Good News:

Scott was "slightly more than cautiously optimistic" that COP21 will turn out better than the Copenhagen "failure". Scott pointed out significant changes in the political landscape over the past 6 years including:

• Cheaper green technology, such as solar panels.
• Investment groups and banks who see potential in renewable energy.
• Companies from all sectors, including oil, who know that climate change will prevent business as normal.
• Health experts worried about how warmer temperature will affect disease.
• Militaries who can no longer balance being combat ready and first responders for extreme weather.
• Support from people such as Pope Francis, movie stars, and You! Public opinion helps drive what politicians are willing to offer.

My Takeaways:

I am pessimistically hopeful (as odd as that sounds) that countries may be able to cut more CO₂ emissions to get closer to the 2^oC goal. However after Scott's talk I am reasonably optimistic that they will be able to sign some meaningful agreement. This is based on the number of parties, representing a whole spectrum of backgrounds, who are pressuring governments during this negotiation.

Solar Tiles: The Future Looks Sleek

The option to go solar is becoming more 
elegant. Source: Alistar King

In my last post, I mentioned my preference to solar roofs over white roofs. Luckily the option of going solar is becoming cuter! Clunky panels are no longer the only option, you can now get solar tiles that blend with your current shingles. However, curb appeal comes with a price tag. You'll need to balance aesthetics and economics.

Price comparison not including installation for solar tiles. The cost of installing solar tiles may not pay off in energy savings, but this chart does not take into account any difference in property value. Source: The Eco Experts

Not Black and White: The Complications of White Roofs

Source: Jaun Carlos PE

After talking about green roofs, I was excited to laud the advantages of white roofs. They increase the albedo of the roofs allowing sunlight to bounce off of them. Which in turn keeps homes and cities cooler, so less energy is spent running the air conditioning. Unlike green roofs, they can be a cheap renovation for any building. (That's US$151 savings during installation for ever square meter!) Pack up shop, we solved the crisis with a few cans of paint!

I should have known that it might be too good to be true. A Stanford study looked at the global effects of a world filled with white roofs and found that the price for a locally cooled city was an increase in total global temperature. Their model predicted a .02^oC decrease in temperature around areas with white roofs but an increase of .07^oC worldwide. Part of the problem is soot and other air pollutants, heated from above and below, causing extra warming.

A study of the economic costs and benefits of environmental roofing found that white roof more economical for global cooling.  However, this was based on CO₂ offset by saving energy and relief of the urban heat island. Since there was no mention of the global heating caused by increased white roof, I tend to be a little skeptical.

Even if the white roof didn't warm the planet on a global scale, there are some areas where they would still not be worthwhile on the local scale. Cities with cooler climates may find that the savings from cooling in the summer are not offset by the additional heating in the winter. 

I wish I could say that a white roof is a great substitution if you can't have a green roof. However based on my reading, I'm afraid that running blindly into adapting white roofs may backfire. So for now, if it's not easy being green consider being solar. Perhaps absorbing light and using it as clean energy is better than reflection.

The Shire of London: The Benefits of Green Roofs

Source: Hobbiton Movie Set Tours

While they may invoke images of Hobbits and the Shire, green roofs could be part of the solution to keeping cool in a warming world. The urban heat island effect (urban areas becoming warmer than surrounds due to more pavement) can raise the temperature in the city by 12^oC at night and currently affects 54% of the world's population.


Source: Marilyn Novy

The reflectivity (albedo) and latent cooling are what draw people to green roofs, but much of their temperature regulation comes from insulation (Del Barrio, 1998). They are most cost effective for old uninsulated buildings, which make up 50% of the UK's homes and businesses. This reduction in energy for heating and cooling will help mitigate CO₂ emissions.

People may argue against this initiative because of the expense (10-14% more for a 60-year roof). However green roofs provide benefits that plain old insulation does not offer. They reduce runoff, cool the outdoor temperature (especially when paired with green walls between close buildings), capture pollutants (notably ozone ), and create easy access to nature. This seems like a lovely way to combine adaptation with an improved lifestyle.

Things Are Going to Get Extreme

When thinking about climate adaptation, it's hard to figure out exactly where to start. The Intergovernmental Panel on Climate Change (IPCC) said we could expect an increase of:

Source: The Washington Sun

• milder cold days
• warmer hot days
• heat waves
• heavy precipitation
• droughts
• intense cyclones
• high sea levels

I've seen a lot of this on the news. And whenever one of these events occurs I am reminded that climate change brings the threat of similar events. But what really scared me during my research, my 'oh wow' moment, was looking at these 4 squiggly graphs.



PR (probability ratio): P1/ P0 where P1 is the probality of an event happening
after a given global mean warming  and P0 is the probability of it happening
before the industrial revolution.

FAR (fraction of attributable risk): 1-PR which yield the amount that humans
contributed to the probability of a set of events occurring

Blue: Daily weather that had a 1 in 100 chance of happening before the industrial revolution

Red:  Daily weather that had a 1 in 1000 chance of happening before the industrial revolution

Source: Fischer, Knutti, 2015

These graphs are the predictions of 25 different models and show the expected trends for heavy precipitation (a & c) and extreme heat (b&d). For both heat and precipitation, the more unusual the event the more its frequency will increase. These same events will probably be, in part, due to human activity. (Fischer, Knutti, 2015) Knowing the resulting death and distruction from extreme events, society needs to take a long hard look in the mirror. The scale of the temperature increase and our respective blame dwarfs the increase for heavy precipitation, which was not what I expected growing up on the East Coast of the US.

Looking at these graphs, knowing that we are currently at .85^oC global increase, the international goal of 2^oC seems recklessly high. And seeing how the current COP21 pledges would result in a 2.7^oC increase, adaptation need to be swift. Therefore, I plan on first looking at preparations for higher temperatures and droughts.

Practicing What I Preach

I decided to figure out my own carbon footprint. After looking through a few online calculators, I opted for Carbon Independent. It was comprehensive and transparent with a simple design. I loved how it broke down each item in terms of CO₂ used. It also took into account the CO₂ that public institutions, such as my university, release on my behalf. After quickly filling in the form based on my time in London since September, I hit 'View/Print Summary' and...




Source: Carbon Independent

 

Yikes! One year in London, living my current lifestyle, would lead to 9.04 tonnes of CO₂ released into the atmosphere.

Unfortunately, I live in university housing, so improving the sustainability of my home will be difficult. Instead I must *gulp* change my lifestyle. I will be updating my progress in a month, and we'll see how I am living up to the new standards.

In the meantime, what's your CO₂ emissions?

Preventing the Worst

TED: Climate change is happening. Here's how we adapt.

Source: ted.com

Upon first watching Alice Bows-Larkin's TED talk I walked away with three primary thoughts.

1. A 4°C change in the atmosphere is scary. With infrastructure not being able to handle the new strain, corn and wheat yields down 40%, rice yields down 30%, and the pure discomfort of effectively adding 10°C to the hottest days, Hollywood has no excuse for poor source material in their disaster films.
2. "Wow, I haven't heard anyone say that we can actually keep temperature change below 2°C globally in long time." Alice Bows-Larkin's cure was for the wealthiest citizens and nations (e.g. anyone able to read this blog) should reduce their CO₂ emission by 10% per year. A task that seems challenging but sustainable.
3. The cynical idea that politicians and businesses will never allow the pause on economic growth for "planned austerity".

The amount each country has contributed to climate change
based on their CO₂, methane, nitrous oxide, and
aerosol emissions per billion people.
Source: Mathews, et al., 2014

Climate-Demographic Vulnerability Index based on predicted
climate variability and population growth. The higher numbers
translate to higher vulnerability. Source: Samson, et al.,2011

The paper Alice Bows-Larkins collaborated on and quoted also mentioned an approach forward which I think is promising, "Mitigate for 2°C but Adapt for 4°C". This would involve policies to attempt to curb CO₂ emissions and keep global temperature change below 2°C while preparing infrastructure for 4°C. I believe that this global goal of 2°C temperature change, historically used when regulating emissions, will prevent delays in political system caused by debating new standards. The preparation aspect will allow vulnerable developing nations, who's contribution climate change is minimal, to get support from wealthier nations. 

The paper mentions that assigning accountability may strain international relations. However, for the sake of human rights, I believe that any legal foothold given to the most vulnerable citizens is worthwhile. Another concern the paper mentioned is the possibility of preparations negating any reduction in emissions. I agree, this cannot be allowed to happen. However, this warning calls for innovation not despair.

I am on the 'aim for 2°C and prepare for 4°C' bandwagon. Therefore, I will attempt to reduce my carbon footprint by 10% while posting the adaptions that will help prepare for the worst.