Posts about environment

Creating Low-cost Construction Materials Using Recycled Plastic Waste

Nzambi Matee is a materials engineer and head of Gjenge Makers (in Kenya), which produces sustainable low-cost construction materials made of recycled plastic waste and sand. For her work, Nzambi Matee was recently named a Young Champions of the Earth by the United Nations Environment Programme.

Building blocks for a greener Nairobi

Through trial and error, she and her team learned that some plastics bind together better than others. Her project was given a boost when Matee won a scholarship to attend a social entrepreneurship training programme in the United States of America. With her paver samples packed in her luggage, she used the material labs in the University of Colorado Boulder to further test and refine the ratios of sand to plastic.

It is wonderful to see young people using an understanding of engineering to find ways to improve the world. Taking waste plastic and creating usable products will help reduce pollution and create a better world. We need quite a bit of effort to deal with plastic waste, so I look forward to learning about many more ideas turned into practical solutions in the real world.

Related: Cleaning Up the Plastic Pollution in Our OceansPedal Powered Washing MachineProtecting Cows with Lion LightsDrone Deliveries to Hospitals in Rwanda

Growing Citrus in the Snow

The system uses the constant ground temperature 2.5 meters (8 feet) below ground to heat a greenhouse. The underground-temperature on his farm is 11 degrees (52 degrees Fahrenheit). Other nearby areas range from 9 to 17 degrees (17 is near a hot spring).

Just circulating air through 64 meters (210 feet) of tubing buried 2.5 meters underground is enough to allow citrus and other plants to thrive. Selling at local farmer’s markets brings in a very high profit for farmers that can grow and sell locally.

Using the power of the sun to grow and the constant ground temperature to keep the air warm enough creates an opportunity to grow all year round. The same principles can be used to cool down indoor temperatures in very hot locations near the equator.

Due to the controlled environment growing organically is easy so that further increases the payoff for this type of farming.

The cost of the system can be as low as $25,000 if you have access to a backhoe to dig the trenches for the air pipes and can do much of the labor yourself. That is the cost of just the heating systems for a conventional greenhouse.

I really like this type of intersection of engineering and business (as well as environment and health benefits – providing healthy local food) that creates value to society by using our knowledge effectively.

Learn more at Citrus in the Snow. The Nebraska farmer (seen in the video) has been growing Citrus in Nebraska this way since 1992.

Related: Sustainable Ocean FarmingBeehive Fence Protects Farms from ElephantsFor Many Crops Ants Can Provide Pest Protection Superior or Equal to Chemicals at a Much Lower CostSmall Farm Robots

In Many Crops Ants Can Provide Pest Protection Superior or Equal to Chemicals at a Much Lower Cost

Ants are as Effective as pesticides

The review [of over 70 studies] was conducted by Aarhus University’s Dr Joachim Offenberg, an ecologist who has studied ants for almost 20 years. It includes studies of more than 50 pest species on nine crops across eight countries in Africa, South-East Asia and Australia.

Most of the studies in Offenberg’s review are on weaver ants (Oecophylla), a tropical species which lives in trees and weaves ball-shaped nests from leaves. Because weaver ants live in their host trees’ canopy, near the flowers and fruit that need protection from pests, they are good pest controllers in tropical orchards.

All farmers need to do is collect ant nests from the wild, hang them in plastic bags among their tree crops and feed them a sugar solution while they build their new nests. Once a colony is established, farmers then connect the trees that are part of the colony with aerial ‘ant walkways’ made from string or lianas.

After that, the ants need little, except for some water in the dry season (which can be provided by hanging old plastic bottles among the trees), pruning trees that belong to different colonies so that the ants do not fight, and avoiding insecticide sprays.

The review shows that crops such as cashew and mango can be exceptionally well protected from pests by weaver ants.

One three-year study in Australia recorded cashew yields 49% higher in plots patrolled by ants compared with those protected by chemicals. Nut quality was higher too, so net income was 71% higher with ants than with chemicals.

Similar studies in Australian mango crops found that ants could produce the same yield as chemical control, but because the ants were cheaper, and fruit quality better, net income from mangoes produced with ant protection was 73% higher.

Those crops are special cases in which the ants are vastly superior. But in many other cases ants are as effective and much cheaper than chemical options. Different species of ants are suited to protecting different types of drops. Weaver ants require a canopy, other ants can protect crops without a canopy.

I hope more farmers adopt ants to help protect their crop yields.

Related: Pigs Instead of PesticidesWhy Don’t All Ant Species Replace Queens in the Colony, Since Some DoHow To Make Your Own Pesticide with Ingredients from Your KitchenAnother Bee Study Finds CCD is Likely Due to Combination of Factors Including Pesticides (2013)

How Wolves Changed the Yellowstone Ecosystem

A great short video explaining the dramatic changes to the Yellowstone ecosystem with the re-introduction of wolves. Even the rivers changed.

Related: Light-harvesting Bacterium Discovered in YellowstoneFishless FutureThe Sea Otter storyYellowstone Youth Conservation Corps Polar Bears Playing with HuskiesCurious Cat travel photos of Yellowstone National Park

Hacking the Standard Bike Wheel

The Copenhagen Wheel stores energy (from braking…) and provides it when you need it (going up hill…). It is good to see innovation that helps transportation and can encourage people to be more active. Order now for $799.

Related: Engineering a Better World: Bike Corn-ShellerSeparated Bike Lanes Reduced Injuries by 45% and Increased Retail Sales 49% (for nearby stores)Bike Folds To Footprint of 1 WheelSports Engineering at MIT

Outdoor Air Pollution Resulted in 223,000 Cancer Deaths in 2010

The specialized cancer agency of the World Health Organization, the International Agency for Research on Cancer (IARC), announced today that it has classified outdoor air pollution as carcinogenic to humans.

After thoroughly reviewing the latest available scientific literature, the world’s leading experts convened by the IARC Monographs Programme concluded that there is sufficient evidence that exposure to outdoor air pollution causes lung cancer. They also noted a positive association with an increased risk of bladder cancer.

Particulate matter, a major component of outdoor air pollution, was evaluated separately and was also classified as carcinogenic to humans.

The IARC evaluation showed an increasing risk of lung cancer with increasing levels of exposure to particulate matter and air pollution. Although the composition of air pollution and levels of exposure can vary dramatically between locations, the conclusions of the Working Group apply to all regions of the world.

Air pollution is already known to increase risks for a wide range of diseases, such as respiratory and heart diseases. Studies indicate that in recent years exposure levels have increased significantly in some parts of the world, particularly in rapidly industrializing countries with large populations. The most recent data indicate that in 2010, 223,000 deaths from lung cancer worldwide resulted from air pollution.

“The air we breathe has become polluted with a mixture of cancer-causing substances,” says Dr Kurt Straif.

The stories of amazingly high (and persistent) air pollution levels in China have been continuing for years. But, while China, likely represents several of the worst existing air pollution conditions hundreds of thousands have died outside China due to air pollution just in the last 5 years.

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Deadly Trio of Acidification, Warming and Deoxygenation Threaten Our Oceans

An international panel of marine scientists is demanding urgent remedies to halt ocean degradation based on findings that the rate, speed and impacts of change in the global ocean are greater, faster and more imminent
than previously thought.

Professor Dan Laffoley, International Union for Conservation of Nature, said: “What these latest reports make absolutely clear is that deferring action will increase costs in the future and lead to even greater, perhaps irreversible, losses. The UN climate report confirmed that the ocean is bearing the brunt of human-induced changes to our planet. These findings give us more cause for alarm – but also a roadmap for action. We must use it.“

Results from the latest International Programme on the State of the Ocean (IPSO)/IUCN review of science on anthropogenic stressors on the ocean go beyond the conclusion reached last week by the UN climate change panel the IPCC that the ocean is absorbing much of the warming and unprecedented levels of carbon dioxide and warn that the cumulative impact of this with other ocean stressors is far graver than previous estimates.

Decreasing oxygen levels in the ocean caused by climate change and nitrogen runoff, combined with other chemical pollution and rampant overfishing are undermining the ability of the ocean to withstand these so-called ‘carbon perturbations’, meaning its role as Earth’s ‘buffer’ is seriously compromised.

Professor Alex Rogers of Somerville College, Oxford, and Scientific Director of IPSO said: “The health of the ocean is spiraling downwards far more rapidly than we had thought. We are seeing greater change, happening faster, and the effects are more imminent than previously anticipated. The situation should be of the gravest concern to everyone since everyone will be affected by changes in the ability of the ocean to support life on Earth.”

Among the latest assessments of factors affecting ocean health, the panel identified the following areas as of greatest cause for concern:
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