Basic Concepts of Climate Change
Objective: To elucidate the fundamental concepts of climate change and health, and to foster a shared understanding of how climatic factors influence population health. This understanding will serve as a scientific basis for preventive measures and evidenceinformed health policy development.
Subtopics:
- Overview
- Climate
- Climate Change
- Global Warming
- National Strategic Plan for Climate Change
Overview
Climate change, driven by the accumulation of greenhouse gases, exerts profound effects on human health through various mechanisms, including rising temperatures, intensified heatwaves, increased flooding and drought, altered patterns of vectorborne diseases, and more frequent natural disasters. Optimal human health is generally maintained around 20°C, though regional adaptations may shift this threshold. Most adverse health outcomes occur when temperatures deviate significantly from regional norms. As greenhouse gas emissions and global temperatures continue to rise, the frequency and severity of heatrelated health impacts are projected to increase, leading to greater disease burden and mortality worldwide. Studies consistently link higher temperatures and heatwaves to elevated cardiovascular, respiratory, renal, neurological, and psychological health risks. Consequently, comprehensive risk assessment and analysis are essential to mitigate, prevent, and prepare for these growing climaterelated health challenges.
Climate
The term "climate" refers to the longterm average of weather conditions in a specific area over an extended period. Describing a climate includes data such as seasonal mean temperature, precipitation, and wind patterns. "Climate change" refers to any systematic shift in the longterm statistics of climatic variables such as temperature, rainfall, pressure, or wind that persists for several decades or longer. The classical period adopted for climate characterization spans 30 years, as defined by the World Meteorological Organization (WMO). Since 1956, the WMO has recommended that each member state recalculate its 30year climate statistics every decade.
Climate Change
Climate change is a major global environmental challenge characterized by rising temperatures, altered precipitation patterns, and an increase in extreme weather events such as heatwaves, floods, and droughts. These climatic shifts affect diverse sectors, including agriculture, water management, environmental protection, human welfare, and health systems, prompting extensive research worldwide. The majority of scientists attribute current climate change primarily to human activities since the Industrial Revolution particularly landuse changes, deforestation, industrialization, and greenhouse gas emissions. According to the UNFCCC, climate change refers to climate alterations resulting from human actions that modify the global atmosphere, leading to outcomes such as global warming, glacial retreat, sealevel rise, frequent coastal floods and landslides, prolonged droughts, desertification, and reduced agricultural productivity, especially in tropical regions.
Global Warming
Global warming refers to the ongoing increase in the Earth’s mean surface temperature, which has had significant and costly consequences for human societies and health. The mechanism of global warming occurs as carbon dioxide and other greenhouse gases accumulate in the atmosphere, trapping solar radiation and emitted terrestrial infrared radiation. Observable impacts include accelerated melting of glaciers and Arctic sea ice. The primary consequences of global warming include:
- Desertification
- Accelerated melting of snow and ice
- Rising sea levels
- Stronger storms and cyclones
Another critical effect of global warming is the rapid melting of snow and ice, causing sealevel rise and subsequent secondary consequences. This process is further amplified by thermal expansion of seawater due to warming and increased water volume from glacial melt. Global warming also heightens cyclone activity.
