10.1 Climate change and environmental risks

Climate change poses significant risks to human societies and ecosystems. Rising temperatures, changing precipitation patterns, and extreme weather events can have far-reaching consequences. Assessing and managing these risks is crucial for effective risk management.

This topic explores key climate change risks like sea level rise, extreme weather, and impacts on agriculture and health. It also examines greenhouse gas emissions, environmental risks, impact assessment methods, and strategies for mitigation and adaptation.

Climate change risks

• Climate change poses significant risks to human societies and natural ecosystems
• Rising temperatures, changing precipitation patterns, and more frequent extreme weather events can have far-reaching consequences
• Assessing and managing climate change risks is a critical component of risk assessment and management

Rising sea levels

Top images from around the web for Rising sea levels

• 

  Frontiers | Coastal Flooding in the Maldives Induced by Mean Sea-Level Rise and Wind-Waves: From ... View original

  Is this image relevant?

• 

  Frontiers | Coastal Flooding in the Maldives Induced by Mean Sea-Level Rise and Wind-Waves: From ... View original

  Is this image relevant?

• 

  Frontiers | Coastal Flooding in the Maldives Induced by Mean Sea-Level Rise and Wind-Waves: From ... View original

  Is this image relevant?

• 

  Frontiers | Coastal Flooding in the Maldives Induced by Mean Sea-Level Rise and Wind-Waves: From ... View original

  Is this image relevant?

1 of 2

Top images from around the web for Rising sea levels

• 

  Frontiers | Coastal Flooding in the Maldives Induced by Mean Sea-Level Rise and Wind-Waves: From ... View original

  Is this image relevant?

• 

  Frontiers | Coastal Flooding in the Maldives Induced by Mean Sea-Level Rise and Wind-Waves: From ... View original

  Is this image relevant?

• 

  Frontiers | Coastal Flooding in the Maldives Induced by Mean Sea-Level Rise and Wind-Waves: From ... View original

  Is this image relevant?

• 

  Frontiers | Coastal Flooding in the Maldives Induced by Mean Sea-Level Rise and Wind-Waves: From ... View original

  Is this image relevant?

1 of 2

• Melting glaciers and ice sheets, combined with thermal expansion of ocean water, contribute to rising sea levels
• Coastal communities and low-lying islands are particularly vulnerable to flooding, erosion, and saltwater intrusion
• Examples of at-risk areas include the Maldives, Bangladesh, and the Netherlands

Increased frequency of extreme weather

• Climate change is expected to increase the frequency and intensity of extreme weather events such as hurricanes, heatwaves, and droughts
• These events can cause significant damage to infrastructure, disrupt economic activities, and threaten human lives
• Examples include Hurricane Katrina (2005), the European heatwave (2003), and the Australian bushfires (2019-2020)

Impacts on agriculture and food security

• Changes in temperature and precipitation patterns can affect crop yields and the availability of water for irrigation
• Droughts, floods, and pest outbreaks can lead to crop failures and food shortages
• Examples of vulnerable regions include sub-Saharan Africa, South Asia, and Central America

Risks to human health

• Climate change can exacerbate health risks such as heat stress, respiratory diseases, and the spread of infectious diseases
• Vulnerable populations, such as the elderly and those with pre-existing health conditions, are particularly at risk
• Examples include the increased incidence of malaria in highland areas of Africa and the health impacts of air pollution in urban centers

Economic costs of climate change

• The economic costs of climate change can be substantial, including damages to infrastructure, reduced agricultural productivity, and disruptions to global trade
• Adaptation and mitigation measures also require significant investments
• Examples include the estimated $160 billion in damages caused by Hurricane Harvey (2017) and the costs of building sea walls to protect coastal cities

Greenhouse gas emissions

• Greenhouse gases, such as carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O), trap heat in the Earth's atmosphere, leading to global warming
• Understanding the sources and dynamics of greenhouse gas emissions is crucial for developing effective mitigation strategies
• Reducing greenhouse gas emissions is a key goal of international climate agreements and national policies

Sources of greenhouse gases

• Burning fossil fuels (coal, oil, and natural gas) for energy production and transportation is the primary source of anthropogenic CO2 emissions
• Agriculture, particularly livestock farming and rice cultivation, is a major source of CH4 emissions
• Deforestation and land-use changes release stored carbon and reduce the capacity of ecosystems to absorb CO2

Carbon dioxide vs methane

• CO2 is the most abundant greenhouse gas and has a long atmospheric lifetime (hundreds to thousands of years)
• CH4 has a shorter atmospheric lifetime (around 12 years) but a much higher global warming potential than CO2 over a 100-year period
• Reducing CH4 emissions can have a more immediate impact on slowing the rate of global warming

Role of human activities

• Human activities, such as fossil fuel combustion, deforestation, and industrial processes, have significantly increased the concentration of greenhouse gases in the atmosphere since the Industrial Revolution
• The Intergovernmental Panel on Climate Change (IPCC) has concluded that human influence is the dominant cause of observed global warming since the mid-20th century

Importance of reducing emissions

• Reducing greenhouse gas emissions is essential for limiting the extent of future climate change and its associated risks
• The Paris Agreement aims to keep the global average temperature increase well below 2°C above pre-industrial levels and to pursue efforts to limit it to 1.5°C
• Achieving these targets requires rapid and substantial reductions in emissions across all sectors of the economy

Environmental risks

• In addition to climate change, human activities pose various other environmental risks that can have significant impacts on ecosystems and human well-being
• Assessing and managing these risks is an important aspect of environmental risk assessment and management
• Many environmental risks are interconnected and can exacerbate the impacts of climate change

Deforestation and habitat loss

• Deforestation, primarily driven by agricultural expansion, urbanization, and logging, leads to the loss of biodiversity and ecosystem services
• Forests play a crucial role in regulating the Earth's climate by absorbing CO2 and maintaining the water cycle
• Examples of deforestation hotspots include the Amazon rainforest, the Congo Basin, and Southeast Asia

Biodiversity loss and extinction

• Human activities, such as habitat destruction, overexploitation, and pollution, are driving a rapid loss of biodiversity and increasing the risk of species extinctions
• The loss of biodiversity can disrupt ecosystem functions and services, such as pollination, pest control, and nutrient cycling
• Examples of threatened species include the Sumatran tiger, the mountain gorilla, and the Hawaiian honeycreeper

Air and water pollution

• Air pollution, caused by emissions from industries, transportation, and households, can have severe impacts on human health and the environment
• Water pollution, resulting from agricultural runoff, industrial discharges, and inadequate waste management, can degrade aquatic ecosystems and compromise water security
• Examples include the air pollution crisis in New Delhi, India, and the contamination of the Ganges River

Soil degradation and desertification

• Unsustainable land management practices, such as overgrazing, intensive farming, and deforestation, can lead to soil erosion, nutrient depletion, and desertification
• Soil degradation reduces agricultural productivity and can exacerbate food insecurity and poverty in affected regions
• Examples include the Dust Bowl in the United States during the 1930s and the desertification of the Sahel region in Africa

Plastic pollution and marine debris

• The widespread use and improper disposal of plastic products have led to a global crisis of plastic pollution, particularly in marine environments
• Plastic debris can entangle or be ingested by marine life, leading to injury, starvation, and death
• Examples include the Great Pacific Garbage Patch and the impact of microplastics on marine food webs

Assessing climate change impacts

• Assessing the potential impacts of climate change is essential for informing adaptation and mitigation strategies
• Various tools and approaches are used to understand the risks and vulnerabilities associated with climate change
• Assessing climate change impacts involves considering both the physical changes in the climate system and the socio-economic consequences for human societies and ecosystems

Climate modeling and projections

• Climate models, based on mathematical representations of the Earth's climate system, are used to simulate future changes in temperature, precipitation, and other variables
• Models are run under different scenarios of greenhouse gas emissions and land-use changes to project a range of possible future climate conditions
• Examples of climate models include the Coupled Model Intercomparison Project (CMIP) and the Regional Climate Model (RCM)

Vulnerability assessments

• Vulnerability assessments evaluate the potential impacts of climate change on specific regions, sectors, or communities, considering their exposure, sensitivity, and adaptive capacity
• These assessments help identify the most vulnerable areas and populations, as well as the key drivers of vulnerability
• Examples include the vulnerability of coastal cities to sea-level rise and the vulnerability of smallholder farmers to changes in rainfall patterns

Regional and sector-specific risks

• Climate change impacts vary across different regions and sectors, depending on their specific characteristics and vulnerabilities
• Regional assessments focus on the unique risks and adaptation needs of specific geographic areas, such as coastal zones, mountain regions, or urban centers
• Sector-specific assessments examine the potential impacts on key economic sectors, such as agriculture, energy, transportation, and tourism

Tipping points and feedback loops

• Tipping points refer to critical thresholds in the climate system, beyond which abrupt and irreversible changes may occur
• Feedback loops, such as the melting of Arctic sea ice or the release of methane from thawing permafrost, can amplify the effects of climate change
• Examples of potential tipping points include the collapse of the West Antarctic Ice Sheet and the dieback of the Amazon rainforest

Mitigation strategies

• Mitigation strategies aim to reduce greenhouse gas emissions and enhance carbon sinks to limit the extent of future climate change
• These strategies involve a wide range of technological, economic, and policy measures across different sectors
• Implementing effective mitigation strategies requires both individual actions and collective efforts at the local, national, and international levels

Renewable energy technologies

• Renewable energy sources, such as solar, wind, hydro, and geothermal power, offer low-carbon alternatives to fossil fuels
• Deploying renewable energy technologies can help reduce greenhouse gas emissions from the energy sector, which is the largest contributor to global emissions
• Examples of successful renewable energy projects include the Tengger Desert Solar Park in China and the Geysers Geothermal Field in the United States

Energy efficiency and conservation

• Improving energy efficiency in buildings, industries, and transportation can significantly reduce energy consumption and associated emissions
• Energy conservation measures, such as using energy-efficient appliances and adopting sustainable transportation modes, can also contribute to emissions reductions
• Examples include the use of LED lighting, high-efficiency heating and cooling systems, and public transit networks

Carbon pricing and emissions trading

• Carbon pricing mechanisms, such as carbon taxes and emissions trading schemes, aim to put a price on greenhouse gas emissions to incentivize emissions reductions
• These market-based approaches can help internalize the external costs of climate change and drive investments in low-carbon technologies and practices
• Examples include the European Union Emissions Trading System (EU ETS) and the carbon tax in British Columbia, Canada

Afforestation and reforestation

• Afforestation (planting trees on previously unforested land) and reforestation (replanting trees in deforested areas) can help remove CO2 from the atmosphere and store it in biomass and soils
• These nature-based solutions also provide co-benefits, such as biodiversity conservation, soil protection, and water regulation
• Examples include the Bonn Challenge, a global initiative to restore 350 million hectares of deforested and degraded land by 2030

Geoengineering and carbon capture

• Geoengineering refers to large-scale interventions in the Earth's climate system to counteract the effects of global warming, such as solar radiation management or ocean iron fertilization
• Carbon capture and storage (CCS) technologies aim to capture CO2 emissions from point sources, such as power plants or industrial facilities, and store them underground or in other long-term sinks
• Examples include the Sleipner CCS project in Norway and the Climeworks direct air capture plant in Switzerland

Adaptation measures

• Adaptation measures aim to reduce the vulnerability and increase the resilience of human societies and ecosystems to the impacts of climate change
• These measures involve a range of strategies and actions to prepare for and adjust to the changing climate conditions
• Effective adaptation requires a context-specific approach that considers the unique risks, capacities, and priorities of different regions and communities

Infrastructure resilience

• Enhancing the resilience of critical infrastructure, such as buildings, roads, bridges, and power grids, can help reduce the risks of damage and disruption from extreme weather events
• Resilient infrastructure design and construction practices, such as elevating structures, using flood-resistant materials, and incorporating green infrastructure, can improve the ability to withstand and recover from climate impacts
• Examples include the Thames Barrier flood defense system in London and the climate-resilient housing project in Bangladesh

Disaster risk management

• Strengthening disaster risk management capacities, including early warning systems, emergency response plans, and post-disaster recovery and reconstruction, can help minimize the impacts of climate-related disasters
• Integrating climate change considerations into disaster risk reduction strategies can help anticipate and prepare for future risks
• Examples include the cyclone early warning system in Bangladesh and the community-based flood management program in the Philippines

Agricultural adaptation strategies

• Adapting agricultural practices to changing climate conditions can help ensure food security and support rural livelihoods
• Strategies include adopting drought-resistant crop varieties, improving irrigation efficiency, diversifying crops and livestock, and implementing agroforestry systems
• Examples include the drought-tolerant maize varieties developed by the International Maize and Wheat Improvement Center (CIMMYT) and the climate-smart villages program in India

Ecosystem-based adaptation

• Ecosystem-based adaptation (EbA) involves using biodiversity and ecosystem services to help people adapt to the impacts of climate change
• EbA measures, such as restoring wetlands, protecting coastal ecosystems, and managing forests sustainably, can provide multiple benefits for adaptation, mitigation, and biodiversity conservation
• Examples include the mangrove restoration project in Vietnam and the ecosystem-based adaptation program in the Andean region

Migration and displacement

• Climate change is expected to increase the risk of forced migration and displacement, particularly in vulnerable regions such as low-lying islands, coastal areas, and drought-prone regions
• Addressing the challenges of climate-induced migration requires a comprehensive approach that includes reducing vulnerability, facilitating planned relocation, and protecting the rights of displaced persons
• Examples include the planned relocation of communities in the Carteret Islands, Papua New Guinea, and the climate migration pilot program in Kiribati

International cooperation

• Addressing climate change requires international cooperation and coordination, as the causes and impacts of climate change transcend national boundaries
• International agreements, organizations, and initiatives play a crucial role in facilitating global efforts to mitigate and adapt to climate change
• Effective international cooperation involves sharing knowledge, resources, and responsibilities among countries and stakeholders

United Nations Framework Convention on Climate Change

• The United Nations Framework Convention on Climate Change (UNFCCC) is the main international treaty on climate change, adopted in 1992
• The UNFCCC provides a framework for international cooperation to stabilize greenhouse gas concentrations in the atmosphere and prevent dangerous anthropogenic interference with the climate system
• The Conference of the Parties (COP) to the UNFCCC meets annually to assess progress and negotiate further actions

Paris Agreement and national commitments

• The Paris Agreement, adopted in 2015 under the UNFCCC, aims to strengthen the global response to climate change by keeping the global temperature rise well below 2°C above pre-industrial levels and pursuing efforts to limit it to 1.5°C
• Under the Paris Agreement, countries submit their Nationally Determined Contributions (NDCs), which outline their commitments to reduce greenhouse gas emissions and adapt to climate change
• Examples of NDCs include the European Union's target to reduce emissions by at least 55% by 2030 compared to 1990 levels and China's goal to achieve carbon neutrality before 2060

Role of international organizations

• Various international organizations, such as the United Nations Environment Programme (UNEP), the World Meteorological Organization (WMO), and the Intergovernmental Panel on Climate Change (IPCC), contribute to the global efforts to address climate change
• These organizations provide scientific assessments, capacity building, and support for the development and implementation of climate policies and actions
• Examples include the IPCC's Assessment Reports, which synthesize the latest scientific knowledge on climate change, and the UNEP's Emissions Gap Report, which assesses the progress towards meeting the Paris Agreement goals

Climate finance and technology transfer

• Climate finance refers to the provision of financial resources to support developing countries in their efforts to mitigate and adapt to climate change
• Technology transfer involves the sharing of knowledge, expertise, and technologies to enable the adoption of low-carbon and climate-resilient practices
• Examples include the Green Climate Fund, which aims to support developing countries in reducing emissions and adapting to climate change, and the Climate Technology Centre and Network (CTCN), which facilitates the transfer of climate technologies

Climate change policies

• Climate change policies are the strategies and measures adopted by governments and organizations to address the causes and impacts of climate change
• These policies can take various forms, such as regulations, incentives, market mechanisms, and public investments
• Effective climate change policies require a comprehensive and integrated approach that considers the social, economic, and environmental dimensions of sustainable development

National and sub-national policies

• National governments play a key role in developing and implementing climate change policies, such as setting emissions reduction targets, promoting renewable energy, and regulating industrial emissions
• Sub-national governments, such as states, provinces, and cities, can also adopt their own climate policies and actions, often leading the way in innovative and ambitious initiatives
• Examples include the United Kingdom's Climate Change Act, which sets legally binding emissions reduction targets, and California's cap-and-trade program for greenhouse gas emissions

Regulatory vs market-based approaches

• Regulatory approaches to climate change involve the use of laws, standards, and mandates to control emissions and promote low-carbon practices
• Market-based approaches, such as carbon pricing and emissions trading, aim to create economic incentives for reducing emissions and investing in clean technologies
• Examples of regulatory approaches include energy efficiency standards for appliances and vehicles, while examples of market-based approaches include the Regional Greenhouse Gas Initiative (RGGI) in the northeastern United States

Integration with sustainable development goals

• Climate change policies should be integrated with broader sustainable development goals, such as poverty reduction, food security, and access to clean energy
• The United Nations Sustainable Development Goals (SDGs) provide a framework for aligning climate action with other social, economic, and environmental objectives
• Examples of integrated policies include the promotion of clean cookstoves in developing countries, which can reduce emissions, improve health, and support gender equality

Challenges and barriers to implementation

• Implementing effective climate change policies faces various challenges and barriers, such as political opposition, lack of public awareness, limited financial resources, and technological constraints
• Overcoming these challenges requires building political will, engaging stakeholders, mobilizing resources, and fostering innovation and collaboration
• Examples of challenges include the resistance to phasing out fossil fuel subsidies, the need for large-scale investments in low-carbon infrastructure, and the difficulty of coordinating policies across different sectors and levels of government

Communicating climate risks

• Effective communication of climate risks is essential for raising public awareness, informing decision-making, and mobilizing action to address climate change
• Climate risk communication involves