Browse "Environment"

Displaying 61-80 of 96 results
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Ozone Depletion

Ozone depletion is a chemical thinning of the OZONE LAYER in the stratosphere or upper atmosphere. Scientists determined in the 1970s that it is caused by ozone depleting substances (ODSs), particularly by the use of chlorofluorocarbons (CFCs).

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Ozone Layer

The development of the ozone layer is thought to have been a significant factor permitting the evolution of life on Earth. Ozone is the main atmospheric gas that absorbs the biologically damaging part of the sun's ultraviolet radiation (UV radiation), known as UV-B (ultraviolet-biologically active).

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Peat

Peat, living and partially decomposed organic matter, consists principally of decayed brown mosses, Sphagnum plants, sedges and other semiaquatic plant remains.

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Permafrost

Permafrost is ground remaining at or below 0°C continuously for at least two years. About 50 per cent of Canada is underlain by permafrost, mainly in the Arctic Archipelago, Yukon, Northwest Territories and Nunavut.

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Pesticide

Substances used to control pests include insecticides (for control of insects), fungicides (for disease-causing fungi), herbicides (for weeds), rodenticides (for rodents), avicides (for birds), piscicides (for fish) and nematicides (for nematodes).

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Plant Disease

Plant disease can decrease the economic, aesthetic and biological value of all kinds of plants. Plant pathology (phytopathology) is the study of the nature, causes, prevention and socioeconomic aspects of plant diseases.

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Pollution

Pollution can be defined as the release of any material, energy or organism that may cause immediate or long-term harmful effects to the natural ENVIRONMENT. Pollution was viewed initially as the unsightly mess or visible environmental damage resulting from careless disposal of various materials.

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Pollution Probe Foundation

Pollution Probe was formed in 1969 by a group of University of Toronto students in an effort to address some of the environmental issues that were without a champion at the time. The organization became a registered charity in 1971.

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Reforestation

Many people believe a new sapling must be planted to replace every tree that is harvested. In fact, the FOREST regenerates naturally. After logging, young shoots grow and develop quickly because they have more room and good exposure to sunlight.

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Resource Use

Since prehistoric times, the inhabitants of what is now Canada used vegetation and animals for food, clothing and shelter. They fashioned implements and ornaments from MINERALS and, after the arrival of Europeans, used furs for trading.

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Silviculture

Silviculture is the branch of FORESTRY that deals with establishing, caring for and reproducing stands of trees for a variety of forest uses including wildlife habitat, timber production and outdoor recreation.

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Soil Classification

Classification involves arranging individual units with similar characteristics into groups. Soils do not occur as discrete entities; thus the unit of measurement for soil is not obvious.

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Soil Conservation

Soil conservation is a combination of all methods of management and land use that safeguard the soil against depletion or deterioration by natural or human-induced factors.

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Soil Science

Soil science is the science that deals with soils as a natural resource. Studies focus on soil formation, classification and mapping, and the physical, chemical and biological properties and fertility of soils as such and in relation to their management for crop production.

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Solar Energy

The energy contained in sunlight is the source of life on Earth. Humans can harness it to generate power for our activities without producing harmful pollutants. There are many methods of converting solar energy into more readily usable forms of energy such as heat or electricity. The technologies we use to convert solar energy have a relatively small impact on the environment. However, they each have disadvantages that have kept them from being widely adopted.

In Canada, the use of solar energy to generate electricity and heat is growing quickly and is helping reduce pollution related to energy production. Despite Canada’s cold climate and high latitudes (which get less direct sunlight than mid-latitudes), solar power technologies are used in many places, from household rooftops to large power plants. The Canada Energy Regulator (formerly the National Energy Board) expects solar power to make up 3 per cent of Canada’s total electricity generation capacity by 2040.

Macleans

Sperm Scare

During the mid-1970s, a Canadian Wildlife Service researcher discovered that birds in Lake Ontario were behaving in a bizarre way: unable to find mates, pairs of female herring gulls were nesting together and devotedly tending clutches of eggs that usually turned out to be infertile.