🌦️Atmospheric Science Unit 17 – Climate Change: Mitigation & Adaptation

Climate Change Basics

• Climate change refers to long-term shifts in global or regional climate patterns, primarily caused by human activities that increase greenhouse gas emissions
• The Earth's climate has naturally varied over geological timescales, but the current rapid warming is unprecedented and primarily driven by anthropogenic factors
• Greenhouse gases, such as carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O), trap heat in the Earth's atmosphere, leading to global warming
• The primary source of human-induced greenhouse gas emissions is the burning of fossil fuels (coal, oil, and natural gas) for energy production, transportation, and industrial processes
• Deforestation and land-use changes also contribute to climate change by reducing the Earth's capacity to absorb CO2 and altering the surface albedo
• Climate change manifests in various ways, including rising sea levels, more frequent and intense heatwaves, droughts, and extreme weather events (hurricanes, floods)
• The impacts of climate change are not evenly distributed, with vulnerable communities and developing nations often facing disproportionate risks and challenges

Greenhouse Gas Emissions

• Greenhouse gas emissions have increased significantly since the Industrial Revolution, primarily due to human activities
• Carbon dioxide (CO2) is the most abundant anthropogenic greenhouse gas, accounting for about 76% of total greenhouse gas emissions
  • CO2 emissions primarily come from burning fossil fuels, deforestation, and cement production
• Methane (CH4) is the second most significant anthropogenic greenhouse gas, contributing to about 16% of total emissions
  • CH4 emissions come from sources such as livestock, landfills, and oil and gas production
• Nitrous oxide (N2O) accounts for about 6% of total greenhouse gas emissions
  • N2O emissions are primarily associated with agricultural practices (fertilizer use) and industrial processes
• Other greenhouse gases include water vapor, ozone (O3), and chlorofluorocarbons (CFCs)
• The concentration of atmospheric CO2 has increased from pre-industrial levels of about 280 parts per million (ppm) to over 410 ppm today
• To limit global warming to 1.5°C above pre-industrial levels, as outlined in the Paris Agreement, global greenhouse gas emissions need to be reduced by 45% by 2030 and reach net-zero by 2050

Climate Change Impacts

• Rising global temperatures lead to the melting of glaciers and polar ice caps, causing sea levels to rise and threatening coastal communities and infrastructure
• More frequent and intense heatwaves can cause health problems, particularly for vulnerable populations (elderly, children, and those with pre-existing medical conditions)
• Changes in precipitation patterns can lead to more frequent and severe droughts in some regions, affecting agriculture, water availability, and increasing the risk of wildfires
• Intense rainfall events and flooding can damage infrastructure, displace communities, and lead to loss of life and property
• Ocean acidification, caused by increased absorption of atmospheric CO2, threatens marine ecosystems and the livelihoods of communities dependent on fishing and aquaculture
• Climate change can alter the distribution and abundance of species, leading to biodiversity loss and ecosystem disruption
  • Some species may shift their ranges to higher latitudes or elevations in response to changing conditions
• Climate change can exacerbate existing social and economic inequalities, as vulnerable communities often have fewer resources to adapt to and recover from climate-related disasters

Mitigation Strategies

• Mitigation strategies aim to reduce greenhouse gas emissions and limit the extent of future climate change
• Transitioning to renewable energy sources, such as solar, wind, and hydropower, can significantly reduce emissions from the energy sector
  • Increasing the share of renewables in the global energy mix and phasing out fossil fuels is crucial for achieving emission reduction targets
• Improving energy efficiency in buildings, transportation, and industry can help reduce energy demand and associated emissions
  • Implementing energy-efficient technologies (LED lighting, insulation) and promoting sustainable building design can contribute to emission reductions
• Sustainable land management practices, such as reforestation, afforestation, and reducing deforestation, can enhance carbon sequestration and mitigate climate change
• Promoting sustainable transportation, such as electric vehicles, public transit, and active transportation (cycling, walking), can reduce emissions from the transportation sector
• Implementing carbon pricing mechanisms, such as carbon taxes or emissions trading schemes, can create economic incentives for reducing emissions
• Encouraging sustainable consumption and production patterns, such as reducing food waste and promoting circular economy principles, can help mitigate climate change
• Investing in research and development of low-carbon technologies, such as carbon capture and storage (CCS), can help reduce emissions from hard-to-abate sectors

Adaptation Approaches

• Adaptation approaches aim to reduce the vulnerability of human and natural systems to the impacts of climate change
• Developing early warning systems and emergency response plans can help communities better prepare for and respond to extreme weather events
• Improving infrastructure resilience, such as building flood defenses and upgrading drainage systems, can help protect against the impacts of sea-level rise and intense rainfall
• Implementing water management strategies, such as rainwater harvesting and efficient irrigation techniques, can help address water scarcity and improve agricultural resilience
• Promoting climate-resilient agriculture practices, such as crop diversification and agroforestry, can help farmers adapt to changing conditions and ensure food security
• Protecting and restoring ecosystems, such as wetlands and mangroves, can provide natural buffers against climate impacts and support biodiversity conservation
• Enhancing public health systems and developing heat action plans can help reduce the health risks associated with heatwaves and other climate-related hazards
• Fostering community-based adaptation initiatives and empowering local communities to develop context-specific solutions can improve resilience and adaptive capacity

Policy and Governance

• International agreements, such as the United Nations Framework Convention on Climate Change (UNFCCC) and the Paris Agreement, provide a global framework for addressing climate change
  • The Paris Agreement aims to limit global warming to well below 2°C above pre-industrial levels and pursue efforts to limit it to 1.5°C
• National governments play a crucial role in setting emission reduction targets, implementing climate policies, and allocating resources for mitigation and adaptation efforts
• Subnational governments, such as cities and regions, can also take action to address climate change through local policies and initiatives (building codes, transportation planning)
• Mainstreaming climate considerations into sectoral policies, such as energy, transportation, and agriculture, can help ensure a coordinated and effective response to climate change
• Engaging stakeholders, including businesses, civil society organizations, and indigenous communities, in climate policy development and implementation can foster collaboration and support
• Strengthening institutional capacity and governance mechanisms can help ensure the effective implementation and monitoring of climate policies and actions
• Providing climate finance and support for developing countries can help address the uneven distribution of climate change impacts and enable a global transition to a low-carbon, climate-resilient future

Technology and Innovation

• Technological advancements and innovation play a critical role in addressing climate change by enabling the development and deployment of low-carbon solutions
• Renewable energy technologies, such as solar photovoltaics, wind turbines, and energy storage systems, are becoming increasingly cost-competitive and are crucial for decarbonizing the energy sector
• Energy-efficient technologies, such as LED lighting, high-performance insulation, and smart grid systems, can help reduce energy demand and associated emissions
• Electric vehicles and low-carbon transportation technologies, such as hydrogen fuel cells, can help decarbonize the transportation sector
• Carbon capture, utilization, and storage (CCUS) technologies can help reduce emissions from hard-to-abate sectors, such as heavy industry and power generation
• Digital technologies, such as artificial intelligence, big data analytics, and the Internet of Things (IoT), can support climate change mitigation and adaptation efforts by enabling better monitoring, optimization, and decision-making
• Nature-based solutions, such as ecosystem restoration and green infrastructure, can provide cost-effective and sustainable approaches to climate change adaptation and mitigation
• Fostering research, development, and deployment of climate-friendly technologies through targeted policies, investments, and international collaboration is crucial for accelerating the transition to a low-carbon future

Individual and Community Action

• Individual actions, such as reducing energy consumption, adopting sustainable transportation habits, and making environmentally conscious consumer choices, can collectively contribute to climate change mitigation
  • Simple actions like turning off lights, unplugging appliances, and using public transportation can make a difference when adopted by many individuals
• Community-led initiatives, such as local renewable energy projects, urban gardening, and waste reduction campaigns, can help build resilience and promote sustainable practices
• Raising awareness and educating the public about climate change, its impacts, and the importance of individual and collective action is crucial for fostering a sense of shared responsibility
• Engaging in climate activism and advocacy, such as participating in climate strikes, signing petitions, and supporting environmental organizations, can help build political will for ambitious climate action
• Supporting businesses and organizations that prioritize sustainability and low-carbon practices can create market incentives for climate-friendly products and services
• Adapting lifestyles to minimize carbon footprints, such as reducing meat consumption, minimizing food waste, and choosing energy-efficient appliances, can contribute to emission reductions
• Building social capital and fostering community resilience through local networks, knowledge sharing, and mutual support can help communities better prepare for and respond to climate-related challenges