Ozone Depletion
- O3 gas mainly found in upper atmosphere. Forms a layer that absorbs UV radiation.
- CFCs are substances found in aerosols and fridges in the past which have contributed to the thinning of the ozone layer, a distinct hole forming over Antarctica.
- Less ozone concentration means more UV radiation reaches Earth’s surface.
- UV exposure increases risk of skin cancer where rays cause genetic mutation in skin. Responsible for over 55,000 deaths worldwide in 2012. Australia has highest due to mainly light-skinned population and latitude positioning.
- Also causes cloudy cataracts to form in the lens of the eye, causing blurred vision. Caused blindness in over 20 million worldwide.
Rising Temperatures
- Due to global warming is making heatwaves more common and more intense – results in thermal stress such as dehydration, heat exhaustion and heatstroke.
- Disease vectors may spread to new regions e.g. mosquitoes carrying malaria are currently confined to tropical and subtropical regions but warming climates in milder regions may increase range of incidence.
Agricultural Productivity
- Rising evaporation rates causes salinization of soils – decreasing yields.
- Dry areas expected to get drier making it harder to grow crops.
- Seasonal precipitation patterns changing, in Indonesia that rainy season is becoming shorter and more intense reducing length of growing season.
- Extreme weather events becoming more intense, disrupting agriculture.
- Rising sea levels means saltwater intrusion onto farmland land. – decreasing yields.
- Warmer temps in UK is extending growing season for crops like melons and peaches.
Food Production and Nutritional Standards
- Places where climate change is decreasing crop yields are experiencing local food shortages. Indonesia’s shortened rainy season has created a ‘hunger season’.
- If climate change continues occur rapidly, availability of some food commodities will be reduced in HICs like the UK. Changes to diet can be detrimental to public health.
- Food prices will increase as production decreases. Food becomes less affordable in both LICs and HICs, leading to malnutrition.
- In HICs however, obesity may increase further as unhealthy foods continue to be more affordable than healthier diets.
Prospects for Global Population
- World population reached 7.4 billion in 2016. United Nations predicts that by 2100 it will reach around 11.2 billion.
- Rate of growth is slowing down. In 2005, it was 1.24% per year but by 2015 it had slowed to 1.18%. Expected to continue this trend.
- Projections based on how fertility rates may change in the future.
-
- High Fertility rates = 2.35 children per woman.
- HICs will see population triple. LICs will see an increase of more than five-fold between 2000 and 2300.
- Population will reach 10.63 billion by 2050.
- Medium
- Fertility rates = 1.85 children per woman.
- HICs will see population increase of 7% versus LICs 50% between 2000 and 2300.
- Population will reach 11.2 billion by 2100.
- Low
- Fertility rates = 1.85 children per woman.
- HICs and LICs have relatively similar decrease of about 64% between 2000 and 2300.
Change in Distribution
- Over ½ of population growth by 2050 will have been in Africa = 2.6% per year.
- 3 billion of the 2.4 billion added to global population will be born in Africa.
- Highest population growth in top 48 LICs (27 of which are in Africa).
- 1 in 5 of all people born between now and 2100 will be Nigerian.
- Africa is expected to have almost quadrupled 2100 whereas Asia and Europe projected to have increased and then decreased.
Conflicting Views
- International Institute for Applied Systems Analysis claims population will peak at 9.4 billion in 2075 and then fall below 9 billion by 2100.
- Also claims Nigerian population will not quintuple, it will only triple due to better education.
- They incorporate the projected level of education in a population e.g. education of girls found to be most successful methods at reducing fertility in long term.
Consensus Views
- Global population rate will continue to slow.
- Most rapid growth will be in sub-Saharan Africa.
- Population decline will continue in parts Europe and Japan.
- China, other parts of Asia and the Americas likely to experience decline in future.
- Countries with declining population face new challenges due to an ageing population; life expectancy will continue to rise.
- China will be overtaken by India around 2028 s having largest population.
Future Population-Environment Relationship
- Per capita resource consumption is increasing. As countries become wealthier – the amount of land, energy, food water and materials consumed per person increases as people can afford higher standards of living.
Climate Change
- As population increases so does need to burn fossil fuels and increase greenhouse gases in the atmosphere causing changing climates, sea levels and weather patterns. Sea level rise threatening low-lying regions like Bangladesh.
Destruction of Natural Habitats
- Within next 50 years, a quarter of the world’s forests will have been lost to deforestation to provide land and resources for growing population.
Water Supplies
- Over one billion in LICs lack access to safe drinking water. Predicted future world conflicts will be driven by population growth and demand for water security. Underground aquifers are being depleted more rapidly than they are being replenished.
Soil Erosion
- 40% of arable soil is being used for farming purposes worldwide and this is being seriously degraded. Increased population density in Uganda will result in major degradation of the very soil they rely on for livelihoods.
Meat Production
- As LICs grow and become more developed, demand for protein diets like in HICs increases and so does production of meat and clearance of forest for cattle farms. Cattle release methane, a prominent greenhouse gas contributing to climate change.
- However, fertility rates dropping, and population increase is slowing meaning less of a long-term impact on environment.
- Also, resource use is becoming more efficient due to technological advances and regulations reducing consumption such as Paris Agreement limiting greenhouse gas emissions and waste disposal.
- Although consumption may exceed attempts to regulate and be more efficient, resulting in exhaustion.
Population Change/Migration Case Study – Poland/UK
- In 2004, 8 Eastern European countries including Poland joined the EU as the A8. Enabled free movement of people and labour between member states – UK government estimated over 15,000 migrants from A8 countries to move here.
- UK was one of the few that didn’t restrict migration from the A8 countries.
- By 2006, 447,000 applied to work here from the A8, rather than predicted 15,000.
- At the time unemployment was high in Poland (18.2% and in some rural areas it was 40%). In the UK it was 5.1%.
- Poland’s GDP was considerably lower at $12,700 compared to UK’s $30,900.
- Poland also experiencing housing shortages with 300 dwellings for every 1000 people.
Impacts on Poland
- ‘Brain drain’ as more educated and skilled moved abroad leaving a shortage of these workers. 40% of first wave migrants were university educated.
- 2011 – £600 million worth of remittances sent home from UK to Poland, stimulating Polish economy.
- Unemployment fell from 19% to 9.5% in four years due to new job vacancies.
Impacts of UK
- £2.54 billion contributed to UK’s economy by Eastern European migrants.
- 80% of migrants were 18-35, off-setting the trend for ageing population structure.
- Social tensions and hate crimes increased tenfold against migrant minorities.
- Poland is now the most common non-UK country of birth, overtaking India (2016).