What is ozone depletion?
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What is ozone depletion?
Ozone depletion is the thinning of the layer of ozone (O3) in the upper atmosphere that protects the earth from the sun's shortwave ultraviolet radiation.
Define ultraviolet radiation (UVR).
Ultraviolet radiation is a type of solar radiation that can be harmful to human health in high doses.
What are the main health risks associated with increased UVR exposure?
The main health risks associated with increased UVR exposure are skin cancer and cataracts.
True or False?
The ozone layer has fully recovered since the Montreal Protocol.
False.
The ozone layer is recovering but will take another 50 years to fully thicken to its original levels.
Define cataracts.
Cataracts are caused by the lens of the eye becoming cloudy, leading to blurred vision .
What factors increase the risk of skin cancer and cataracts?
Factors that increase the risk of skin cancer and cataracts include geographic location, time of day, and altitude.
True or False?
Climate change is predicted to have only negative impacts on human health.
False.
While climate change has many negative health impacts, there are some positive impacts such as increased food supply in some parts of the world.
What are the three main ways climate change impacts human health?
Climate change impacts human health through:
Direct impacts of extreme weather.
Indirect impacts of reduced environmental quality.
Indirect impacts of reduced mental health.
Define vector-borne diseases.
Vector-borne diseases are illnesses due to parasites, viruses, and bacteria that are transmitted by vectors like mosquitoes, ticks and flies.
True or False?
Higher altitudes have lower levels of UVR exposure.
False.
At higher altitudes, UVR levels increase as there is less atmosphere to absorb the radiation.
What is the UN's prediction for global population in 2050?
The UN predicts global population will reach 9.7 billion in 2050.
Define the fertility replacement rate.
The fertility replacement rate is the average number of children each woman needs to have to maintain current population levels, typically 2.1 children per woman.
What is a pro-natalist policy?
A pro-natalist policy is a government strategy aimed at encouraging higher birth rates.
True or False?
Global population growth rates are increasing.
False.
Global population growth rates are in decline, although total population is still increasing.
Define the dependency ratio.
The dependency ratio is the ratio of the dependent population (young and elderly) to the working-age population, expressed as a percentage.
What percentage of the global population is predicted to be over 60 by 2050?
Approximately, 25% of the global population (excluding Africa) is predicted to be over 60 by 2050.
True or False?
All countries are expected to follow the same population growth trends in the future.
False.
Population growth rates will continue to vary spatially, with some countries growing while others decline.
What is one strategy used to manage declining populations in developed countries?
One strategy used to manage declining populations in developed countries is encouraging immigration of working age population.
What impact does educating women have on fertility rates?
Educating women tends to reduce fertility rates, as it gives women more career opportunities and less time for childbearing.
True or False?
The fertility rate in Niger has remained constant over the past 30 years.
False.
The fertility rate in Niger has fallen from 7.8 to 6.5 in the last 30 years, although this decrease is less than expected.