Global Population Futures (AQA A-Level Geography): Revision Notes

Global population futures

Introduction to population futures

There is considerable debate about what will happen to the global population during the twenty-first century. Following the rapid population increase in the twentieth century, questions arise about whether the planet can sustain continued growth. With more people comes increased demand for resources, particularly as populations in developing nations become more affluent and desire higher living standards.

Contrasting perspectives on population growth

Two major schools of thought offer different views on how population growth relates to environmental limits and future sustainability.

Neo-Malthusian perspectives

This viewpoint presents a pessimistic outlook on population growth. Neo-Malthusians believe that:

Philosophical foundation:

• The environment sets definite boundaries that determine how large populations can grow
• Physical limits cannot be overcome indefinitely
• This is a deterministic worldview

Resource concerns: The Neo-Malthusian perspective highlights several worrying trends:

• Ecological footprints are expanding as people consume more resources
• Resource consumption is leading to depletion of finite materials
• Output per person is declining whilst prices for goods are rising
• Environmental degradation is increasing
• Pollution levels and biodiversity loss are accelerating

Predicted consequences:

• Population growth will eventually lead to severe food shortages, famines and disease outbreaks
• These crises will cause rapid population crashes (negative feedback)
• Population control measures may need to be introduced to prevent catastrophe

Supporting evidence: Neo-Malthusians point to current problems as proof their concerns are valid:

• Over 800 million people worldwide suffer from undernourishment
• Frequent droughts and famines occur, especially in sub-Saharan Africa
• Wars and conflicts erupt over access to food, water and energy resources
• Global warming and climate change are intensifying environmental pressures

Cornucopian perspectives

This viewpoint presents an optimistic outlook on population growth. Cornucopians argue that:

Philosophical foundation:

• Human ingenuity, creativity and problem-solving abilities can overcome natural constraints
• Technology enables us to expand the limits imposed by the environment
• This is a possibilistic worldview (possibilities exist through human action)

Resource optimism: Cornucopians challenge Neo-Malthusian fears by highlighting positive trends:

• As certain resources become depleted, alternatives are developed
• Society is switching from non-renewable to renewable resources (such as solar and wind energy)
• Increased recycling and more efficient use of materials reduces waste
• Innovation continually finds ways to repair environmental damage
• Growing awareness of environmental issues drives more sustainable practices

Predicted outcomes:

• Humanity adapts successfully to changing conditions through innovation
• Population growth slows down naturally as societies develop economically and socially
• This follows the demographic transition theory - as countries become wealthier, birth rates decline voluntarily without coercive population control

Supporting evidence: Cornucopians cite improvements in human welfare:

• Food production has increased through agricultural intensification and new technologies (e.g. the Green Revolution)
• Adoption of renewable energy technologies is accelerating globally
• New sustainable technologies are being developed to address environmental challenges

Julian Simon: a key cornucopian thinker

Julian Simon was an influential academic who championed the cornucopian perspective. He argued that despite rapid population growth, human material welfare has improved across virtually all parts of the world.

Simon's key arguments:

Simon used factual evidence to support his optimistic view:

• Air quality in wealthy countries has become safer to breathe
• Water cleanliness has improved overall
• Cropland conditions are improving rather than deteriorating
• Food production increases have consistently matched or exceeded population increases

Challenges to Simon's arguments:

Whilst many of Simon's claims are supported by data, more recent trends reveal flaws in his reasoning:

• His premise that resources increase alongside population growth has weaknesses
• As global population has expanded, resource availability has not kept pace in all areas
• Environmental degradation continues despite technological advances

The debate between Neo-Malthusian and cornucopian perspectives remains active. Both viewpoints present evidence and arguments to support their positions. As students of population and environment, it is important to research both sides and develop an informed understanding of this complex issue.

Health impacts of global environmental change

Environmental changes caused by human activity are having direct consequences for human health. Two significant examples are ozone depletion and its associated health impacts.

Ozone depletion

What causes ozone depletion?

Ozone ($O_3$) is a form of oxygen composed of three atoms. The stratospheric ozone layer sits in the extreme cold of the polar stratosphere and acts as Earth's protective shield.

• CFCs were widely used in refrigeration, insulation and spray-can propellants
• These halogenated chemicals react with and destroy ozone molecules
• Destruction occurs mainly during late winter and early spring
• The process is relatively recent in human history, becoming apparent in recent decades

Why is the ozone layer important?

The stratospheric ozone layer serves a critical protective function:

• It filters out much of the Sun's incoming ultraviolet (UV) radiation
• UV radiation, particularly shorter wavelength UVR, is biologically damaging
• When ozone becomes depleted, more UV rays reach Earth's surface
• This increased UV exposure has harmful impacts on humans, flora and fauna

Skin cancer

Skin cancer is one of the most significant health consequences of ozone depletion and increased UV exposure.

Types of skin cancer:

There are two main categories:

1. Non-melanoma skin cancer - The most common type includes basal cell carcinomas
2. Malignant melanoma - Less common but far more dangerous as it can spread (metastasise) to other organs if not treated early

Global patterns:

• Non-melanoma skin cancer is the fifth most commonly occurring cancer globally
• Over one million diagnoses occurred worldwide in 2018
• Malignant melanoma, whilst less common, has become the nineteenth most common cancer
• Over 300,000 cases of malignant melanoma were diagnosed in 2018

Risk factors:

Melanomas are more likely to affect certain groups:

• Fair-skinned populations (less protective melanin pigmentation)
• Elderly people (cumulative lifetime exposure)
• Those living in lower latitudes (stronger solar radiation)
• Males (slightly higher incidence rates, possibly due to more outdoor occupations)

Cataracts

Cataracts develop when UV radiation damages the proteins in the eye's lens, leading to cloudiness and impaired vision. This is another direct health consequence of increased UV exposure resulting from ozone depletion.