🌡️Intro to Climate Science Unit 14 – Climate Change: Impacts on Human Systems

Key Climate Change Concepts

• Greenhouse gases trap heat in the atmosphere leading to global warming (carbon dioxide, methane, nitrous oxide)
• Anthropogenic activities are the primary driver of current climate change through fossil fuel combustion, deforestation, and industrial processes
  • Burning of coal, oil, and natural gas releases CO2 into the atmosphere
  • Deforestation reduces carbon sinks and contributes to increased atmospheric CO2 levels
• Climate change manifests as rising global temperatures, sea level rise, changes in precipitation patterns, and increased frequency and intensity of extreme weather events
• Positive feedback loops amplify the effects of climate change (melting of Arctic sea ice reduces albedo and increases heat absorption)
• Tipping points in the climate system can lead to irreversible changes (collapse of the West Antarctic Ice Sheet)
• Climate models project future climate scenarios based on different greenhouse gas emission pathways (Representative Concentration Pathways)
• The Paris Agreement aims to limit global temperature rise to well below 2°C above pre-industrial levels and pursue efforts to limit the increase to 1.5°C

Human Systems Affected

• Agriculture and food security are impacted by changes in temperature, precipitation, and extreme weather events affecting crop yields and livestock productivity
• Water resources are strained by altered precipitation patterns, melting glaciers, and increased evaporation leading to water scarcity and competition
• Energy systems face challenges such as reduced hydropower generation due to drought, increased energy demand for cooling, and infrastructure damage from extreme weather
• Transportation networks are disrupted by sea level rise, flooding, and heat waves affecting roads, railways, and airports
• Urban areas are vulnerable to heat stress, flooding, and sea level rise impacting infrastructure, housing, and public health
• Coastal communities are at risk from sea level rise, storm surges, and coastal erosion threatening homes, businesses, and infrastructure
• Tourism is affected by changes in weather patterns, sea level rise, and ecosystem degradation impacting popular destinations and local economies

Environmental Impacts on Society

• Biodiversity loss and ecosystem degradation reduce the provision of essential services such as pollination, water filtration, and carbon sequestration
  • Coral reef bleaching due to ocean warming and acidification affects marine biodiversity and coastal protection
  • Deforestation and habitat fragmentation disrupt wildlife populations and ecological processes
• Changing climate patterns alter the distribution and abundance of species leading to shifts in ecological communities and potential invasive species spread
• Drought and water scarcity impact agricultural productivity, food security, and rural livelihoods
  • Reduced crop yields and livestock productivity due to water stress and heat waves
  • Increased competition for water resources among agriculture, industry, and human consumption
• Extreme weather events cause damage to infrastructure, homes, and businesses disrupting daily life and economic activities
  • Flooding can lead to property damage, displacement, and increased risk of waterborne diseases
  • Wildfires destroy homes, ecosystems, and air quality affecting public health and safety
• Sea level rise and coastal erosion threaten low-lying areas and coastal communities leading to displacement and loss of land and resources
• Ocean acidification affects marine ecosystems and the livelihoods of communities dependent on fisheries and aquaculture

Economic Consequences

• Climate change impacts various economic sectors such as agriculture, tourism, energy, and infrastructure leading to financial losses and increased adaptation costs
• Reduced agricultural productivity due to droughts, floods, and changing weather patterns affects food prices and rural incomes
  • Crop failures and reduced yields can lead to economic losses for farmers and food insecurity for communities
  • Adaptation measures such as irrigation systems and drought-resistant crops require investments
• Damage to infrastructure from extreme weather events results in repair and reconstruction costs burdening governments and businesses
• Increased energy demand for cooling during heat waves strains energy systems and raises costs for households and businesses
• Shifts in tourist destinations due to changing climate conditions affect local economies dependent on tourism revenue
• Insurance costs rise as the frequency and severity of climate-related disasters increase leading to higher premiums and potential uninsurability
• Adaptation and mitigation efforts require significant investments in renewable energy, infrastructure upgrades, and resilience measures

Health and Well-being Effects

• Extreme heat events increase the risk of heat stress, heat stroke, and cardiovascular diseases particularly affecting vulnerable populations (elderly, children, outdoor workers)
• Air pollution from wildfires and increased ground-level ozone formation exacerbates respiratory illnesses such as asthma and allergies
• Changes in temperature and precipitation patterns alter the distribution and transmission of vector-borne diseases (malaria, dengue fever)
  • Warmer temperatures and changes in rainfall extend the geographic range of disease-carrying mosquitoes
  • Flooding can create breeding grounds for mosquitoes and increase the risk of outbreaks
• Water scarcity and contamination due to droughts and floods impact access to clean drinking water and sanitation increasing the risk of waterborne diseases
• Mental health is affected by the stress and trauma associated with climate-related disasters, displacement, and loss of livelihoods
• Food insecurity resulting from reduced agricultural productivity and rising food prices affects nutrition and overall health, particularly in developing countries
• Vulnerable populations such as low-income communities, indigenous peoples, and those with pre-existing health conditions are disproportionately affected by climate change health impacts

Social and Cultural Shifts

• Climate change impacts traditional livelihoods and cultural practices tied to natural resources and weather patterns (farming, fishing, hunting)
  • Indigenous communities relying on subsistence agriculture and traditional ecological knowledge are particularly vulnerable
  • Loss of cultural heritage sites and landscapes due to sea level rise, coastal erosion, and extreme weather events
• Displacement and migration due to sea level rise, coastal erosion, and extreme weather events disrupt social networks and cultural ties
  • Climate refugees face challenges in resettlement, integration, and access to resources and services
  • Receiving communities may experience increased pressure on infrastructure, services, and social cohesion
• Inequalities and social vulnerabilities are exacerbated by climate change as disadvantaged communities have fewer resources for adaptation and recovery
• Shifts in agricultural practices and food availability affect cultural dietary habits and traditional cuisines
• Climate change impacts on natural landscapes and biodiversity alter the aesthetic and recreational value of places holding cultural significance
• Adaptation and mitigation efforts require changes in lifestyles, consumption patterns, and social norms challenging cultural values and practices

Adaptation Strategies

• Developing early warning systems and emergency response plans to minimize the impacts of extreme weather events and natural disasters
• Implementing sustainable land management practices (agroforestry, conservation agriculture) to improve soil health, water retention, and crop resilience
• Investing in climate-resilient infrastructure (flood defenses, drought-resistant water systems) to protect communities and assets from climate impacts
  • Upgrading drainage systems and building seawalls to cope with sea level rise and coastal flooding
  • Retrofitting buildings to withstand extreme weather events and improve energy efficiency
• Promoting water conservation and efficiency measures (drip irrigation, rainwater harvesting) to address water scarcity and reduce pressure on water resources
• Diversifying agricultural crops and livestock to spread risks and adapt to changing climate conditions
  • Introducing drought-resistant and heat-tolerant crop varieties
  • Shifting planting dates and cropping patterns based on changing weather patterns
• Enhancing natural carbon sinks through reforestation, afforestation, and ecosystem restoration to mitigate greenhouse gas emissions
• Developing climate change adaptation plans at national, regional, and local levels to identify vulnerabilities and prioritize adaptation actions

Future Projections and Challenges

• Climate models project continued warming, sea level rise, and changes in precipitation patterns throughout the 21st century depending on greenhouse gas emission scenarios
  • Global average temperature is expected to rise by 1.5°C to 4°C by 2100 compared to pre-industrial levels
  • Sea level is projected to rise by 0.3 to 1.1 meters by 2100 threatening coastal communities and low-lying islands
• Extreme weather events such as heatwaves, droughts, floods, and tropical cyclones are projected to become more frequent and intense
• Tipping points in the climate system (melting of the Greenland and West Antarctic ice sheets, thawing of permafrost) could lead to irreversible and catastrophic changes
• Adaptation challenges include financing, technology transfer, and capacity building particularly in developing countries with limited resources
• Mitigation efforts require significant reductions in greenhouse gas emissions from energy, transportation, industry, and land use sectors
  • Transitioning to renewable energy sources and improving energy efficiency
  • Adopting sustainable transportation systems and reducing fossil fuel dependence
• Balancing adaptation and mitigation efforts with sustainable development goals, poverty alleviation, and social equity is a complex challenge
• International cooperation and coordination are crucial for effective global responses to climate change, but political, economic, and social barriers persist