Environmental Science

Unit 5 Overview

Our liquid planet glows like a soft blue sapphire in the hard-edged darkness of space. There is nothing else like it in the solar system. It is because of water.

Will we have enough usuable water?

We are using available freshwater unsustainably by extracting it faster than nature can replace it and by wasting, polluting and underpricing this irreplaceable natural resource.
Freshwater supplies are not evenly distributed, and one of every ten people on the planet does not have adequate access to clean water.

We are managing freshwater poorly.

Freshwater: Water that contains very low levels of dissolved salts. Freshwater is one of our poorly managed resources. It is available at too low a cost to billions of consumers, and this encourages waste and pollution of this resource.

Most of the earth's water is not available
Only 0.024% of the planet's enormous water supply is readily available to people as liquid freshwater.
The rest is in the saly oceans, in frozen polar ice caps and glaciers and in deep underground aquifers.

Principle of sustainability: A serious violation of the full-cost pricing. Global basis, there is plenty of freshwater but it is not distributed evenly Canada has 20% of its liquid freshwater, while China has only 6.5% of the supply.

Freshwater shortages will grow

Freshwater scarcity stress: Comparison of the amount of freshwater available with the amount used by humans. Area are dry climate, drought too many people using a water supply and wasteful of water. Currently about 30% of the earth's land an area roughly five times the size of the United States experiences severe drought.

Reducing water losses

How can we reduce water pollution?

Reducing water pollution requires that we prevent it, work with nature to treat sewage, cut resource use and waste reduce poverty and slow population growth.

Water pollution: Is any change in water quality that can harm living organisms or make the water unfit for human uses such as drinking, irrigation and recreation.

Point sources: Discharge pollutants into bodies of surface water at specific locations through drain pipes, ditches or sewer lines.

Nonpoint sources: Are broad diffuse areas where rainfall or snowmelt washes pollutants off the land into bodies of surface water.

Agricultural activities: Are by far the leading cause of water pollution. The most common pollutants in sediments eroded from croplands.

Mining: Third largest sources. Surface mining distrubs the land, which in turn leads to major erosion of sediments and runoff of toxic chemicals.

Qhat can you do?

Reducing water pollution

Solid and Hazardous waste

The life cycle of a product begins when it is manufactured (its cradle) and ends when it is discarded as solid waste, typically in a landfill or as litter (its grave).

Designer William McDonough wants us to abandon this cradle-to-grave view of the life cycle of products. he argues for a cradle-to-cradle approach, in which we think of products as parts of a continuing cycle instead of as materials that become solid waste that is burned or buried in landfills or that ends up as littler.

He envisions an economy where all products on their parts will be reused repeatedly in other products. Parts that are no longer useful would be degradable so that nutirent cycles could recycle their materials and chemicals.

Cradle-to-cradle design is a form of biomimicry because it helps implement the earth's chemical cycling principle of sustainability.

What enviornmental problems are related to solid and hazardous wastes?

Solid waste contributes to pollution and includes valuable resources that could be used or recycled.

Hazardous waste contributes to pollution, as well as to natural capital degradation, health problems and premature deaths.

Solid waste is piling up

In the natural world, there is essentially no waste because the wastes of one organism become nutrients or raw materials for others in food chains and food webs. This natural cycling of nutrients is the basis of the chemical cycling principle of sustainability.
one major category of waste is.

Solid waste: Any unwanted or discarded material that is not a liquid or a gas.

Two major types of solid waste.

Industrial solid waste: Produce by mines, farms and industries that supply people with goods and services. It also includes construction and demolition waste.

Municpal solid waste(MSW): Often wastes produced by homes and workplace other than facotries.
In more-developed countries, msot MSW is collected and buried in landfills or burned in incinerators.

Ocean garbage patches: There is no away

About 80% of this wate is washed or blown off beaches, pour out of storm drains, and floats down streams and rivers that empty into the sea.

The north pacific garbage patch - viewed as the planet's largest human trash dump - occupies an area estimated to be at least the size of Texas. Such estimates are estimated to be at least the size of Texas.

Research shows that the tiny plastic particles ultimately degrade into microscopic particles that can contain potentially hazardous chemicals. Some long-lived toxins in these microscopic plastic particles can build up to high concentrations in food chains and webs and can end up in fish sandwiches and other forms of seafood.

Since the great pacific garbage patch was discovered, five other huge swirling garbage patches have been found in gyres in the world's other oceans. In total, these garbage patches cover an area of ocean greater than all of the earth's land area - the massive pollution legacy of a throwaway human culture.

Unfortunately, there is no praactical or affordable way to clean up this gigantic amount of marine litter. The only useful approach is to prevent the garbage patches from growing by reducing the production of solid waste.

What harmful chemicals are in your home?

Cleaning:

Paint Products:

General:

Gardening:

Automotive:

How should we deal with solid waste?

A sustainable approach to solid waste is first to produce less of it, then to reuse or recycle it, and finally to safely dispose of what is left.

Waste management: Which focuses on reducing their enviornmental harm.

Waste reduction: Focused on producing much less solid waste and reusing, recycling or composting what is produced as much as possible.

Intergraded Waste management: A variety of coodinated strategies for waste management and waste reduction.

The four Rs of waste reduction



The first three Rs are preferred because they are waste prevention approaches that tackle the problem of waste production before it occurs.

Six strategies that some industries and communitites use to reduce resource use, waste and pollution and promote the cradle-to-cradle approach to design, manufacturing and marketing.
  1. Change industrial processes to eliminate or reduce the use of harmful chemicals.
  2. Redesign manufacturing processes and products to use less material and energy.
  3. Develop products that are easy to repair, reuse, remanufacture, compost or recycle.
  4. Establish cradle-to-cradle responsibility laws.
  5. Eliminate or reduce unnecessary packaging.
  6. Use fee-per-bag waste collection systems.

What can you do?

Reuse:

Recycling
Recycling down into two categories: upcycling and downcycling.

Upcycling: Recycled into a form that is more useful than the recycles item was.

Downcycling: Recycled products are still useful, but not as useful or long-lived as the original item.

These materials can be reprocessed into new, useful products in two ways.

Primary recycling: Involved using materials again for the same purpose.

Secondary recycling: Involves downcycling or upcycling waste materials to make different products such as downcycling used to make sandals.

Composting: Is another form of recycling that mimics nature's recycling of nutrients.

Trade-Offs

Recycling
Advantages:
Reduces energy and mineral use and air and water pollution.
Reduces greenhouse gas emissions.
Reduces solid waste.

Disadvantages:
Can cost more than burying in areas with ample landfills space.
Reduces profits for landfill and incineration owners.
Inconvenients for some.

Cities that make money by recycling and that have higher recycling rates tend to use a single-pickup system for both recycling and nonrecyclable materials, instead of a more expensive two-truck system.

Citizens can take action

Health risks from incinerators and landfills, when averaged over the entire country, are quite low. However, the risks for people living near such facilities are higher.

Manufacturers and waste industry officials point out that something must be done with the toxic and hazardous wastes created in the production of certain goods and services,

Encouraging reuse and recycling

Why aren't reuse and recycling more common?

  1. These strategies must compete with the use of cheap, disposable products that do not include their hidden harmful enviornmental and health costs in their market prices.
  2. The economic playing field is uneven because in most countries, resource extraction industries receive more government tax breaks and subsidies than do reuse and recycling industries.
  3. The demand and thus the price paid for recycled material fluctuates, mostly because individuals buy goods made of recycled materials.
Governments can increase subsides and tax breaks for reusing and recycling materials and decrease subsidies and tax breaks for making items from virgin resources.
Governments can also pass laws requiring companies to take back and recycle or reuse packing and electronic waste discarded by consumers.
With or without government intervention, some industries are finding ways to save money by reusing and recycling their materials.

Biomimicry involves two major steps

  1. Study how natural systems have responded to changes in enviornmental conditions over many millions of years
  2. Copy or adapt these responses within human systems in order to deal with various enviornmental challenges
Resource exchange webs: The wastes of one manufacturer become the raw materials for another. This approach is similar to food webs in natural ecosystems and is a direct application of the cradle-to-cradle concept.