Global challenges Study Guide

Health is often defined as a state of complete physical, mental, and social well-being, not merely the absence of disease or infirmity. This definition highlights that being healthy goes beyond just not being sick. It encompasses a holistic view where various aspects of a person's life contribute to their overall well-being. Disease, on the other hand, refers to any condition that impairs the normal functioning of an organism. This can include infections caused by pathogens like bacteria or viruses, genetic disorders, nutritional deficiencies, and even mental health conditions. The relationship between health and disease is complex and dynamic. It's not a simple case of being either perfectly healthy or acutely diseased; rather, there is a spectrum. An individual can have a disease and still maintain a relatively good level of health in other areas, or they might be free from diagnosed disease but not experience optimal health due to factors like stress or poor nutrition. Many factors influence health. These can be broadly categorised into genetic factors (inherited predispositions), lifestyle choices (diet, exercise, smoking, alcohol consumption), environmental factors (exposure to pollution, access to clean water), and socioeconomic factors (income, education, healthcare access). Disease can also result from a combination of these factors. For example, a genetic predisposition to heart disease might be exacerbated by a poor diet and lack of exercise. Similarly, infectious diseases are influenced by both the presence of pathogens and the host's immune system strength, which can be affected by nutrition and stress. Understanding this complex interplay is crucial for promoting health and preventing disease effectively, focusing on a multi-faceted approach that addresses both individual and societal determinants of well-being.

Biodiversity refers to the variety of living organisms in an ecosystem or on Earth. Maintaining both local and global biodiversity is crucial for the health of the planet and human well-being, though it comes with significant challenges. One major benefit is the provision of ecosystem services. These include clean air and water, pollination of crops, decomposition of waste, and regulation of climate. For example, diverse plant communities are more resilient to disease and pests, which can ensure stable food supplies. Loss of biodiversity can lead to the collapse of these services, impacting human health and economies.

From an economic perspective, biodiversity provides raw materials for industries, such as pharmaceuticals (many medicines are derived from plants), agriculture (new resilient crop varieties), and tourism. Aesthetic and recreational values are also significant, as people enjoy natural landscapes and wildlife. Ethical considerations also play a role; many believe that all species have a right to exist, and humans have a responsibility to protect them.

However, maintaining biodiversity faces numerous challenges. Habitat destruction, often due to human activities like deforestation, urbanisation, and agriculture, is a primary driver of species loss. Pollution, including air, water, and soil pollution, contaminates ecosystems and harms organisms. Climate change, leading to altered weather patterns and rising sea levels, forces species to adapt or face extinction. Overexploitation of resources, such as overfishing or excessive logging, depletes populations faster than they can recover. Finally, the introduction of non-native invasive species can outcompete native species, leading to their decline. Addressing these challenges requires coordinated efforts from governments, communities, and individuals, often involving complex trade-offs between economic development and environmental protection.