Last year, the Intergovernmental Panel on Climate Change (IPCC) began publishing its Sixth Assessment Report (AR6), beginning with the report of Working Group I on the Physical Science Basis of Climate Change. climate change. We have published a summary of key points here. Now it has published the Working Group II (WGII) report which focuses on impacts, adaptation and vulnerability.
This latest report summarizes the current scientific understanding of the observed impacts of climate change on natural and human systems and the vulnerability of these systems to the projected impacts of climate change. It also describes existing adaptations to observed and projected climate change and comments on the feasibility and limitations of adaptations.
Jacobs Global Technology Leader Resilience and Climate Change Craig Clifton and Senior Resilience and Climate Change Technologies Tapash Das again reviewed the key findings of the report.
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Human Influence on the Climate System: A Brief Summary of the Working Group I Report
Climate change 2021: the basis of physical sciences asserted that human influence on the climate system is an established fact and that it is mainly due to emissions of carbon dioxide, methane and nitrous oxide from human activities.
He found that increasing concentrations of greenhouse gases (GHGs) in the atmosphere had contributed to warming of the air, land and oceans, changes in precipitation patterns, retreating glaciers and Arctic sea ice, to sea level rise and to the amplification of many meteorological and climatic phenomena. extremes. He found that some system changes, especially those driving sea level rise, are now effectively irreversible on a human scale.
Global warming of at least 1.5°C (compared to 1.1°C currently) is likely by 2040, even under the most ambitious GHG emissions scenario considered by the IPCC for climate change modeling in AR6.
Observed impacts of climate change
Climate Change 2022: Impacts, Adaptation and Vulnerability reports that even with the current level of warming alone, the impacts of climate change on ecosystems, people, human settlements, infrastructure, and water and food production systems are already pervasive. These impacts result mainly from the increased frequency and intensity of extreme temperatures on land and in the oceans, heavy rainfall, drought and fires.
Changes in natural systems that can be attributed with certainty to climate change have been observed in almost all regions of the Earth. Several species extinctions have been attributed to the effects of climate change. Local species losses and mass mortality events on land and in the oceans were driven by extreme heat, some of which were more severe than expected for 2100. Some 50% of species assessed globally moved further towards the North or South Pole or at a higher altitude.
The amplification of weather and climate events by climate change has exposed millions of people to acute food insecurity and reduced water security – the influences of climate change have contributed to approximately half of the world’s population experiencing severe water shortage for at least part of the year. Sudden losses in food production and food access caused by climatic events and compounded by reduced dietary diversity have increased malnutrition in many vulnerable groups. Food and water insecurity, extreme heat, floods, wildfires, and climate change-related food or water-borne diseases have also adversely affected the physical and mental health of people where these impacts have been evaluated. Climate change contributes to humanitarian crises where climatic hazards interact with high social vulnerability.
Looking Ahead: Risk and Vulnerability to Projected Climate Change
Beyond 2040, climate change is expected to pose many risks to natural and human systems. For all types of risks considered by the WGII, the impacts assessed in the medium and long term (those experienced by 2050 and 2090, respectively) are up to several times higher than those currently observed. The predicted negative impacts and associated loss and damage intensify with each increase in global warming. These impacts will be strongly influenced by short-term (by 2040) mitigation and adaptation measures.
The risk of extinction increases disproportionately from a global warming of 1.5 to 3°C and is particularly high for species with restricted distributions and/or specialized habitat requirements, as well as for species made less resilient by human-induced non-climatic stressors (e.g. pollution, weeds and animals, habitat fragmentation, water resource extraction.)
The ability of natural ecosystems to provide carbon storage and sequestration services is expected to be increasingly affected by heat, wildfires, droughts, vegetation loss and degradation resulting from land use. . Water flow in many major watersheds around the world is expected to be affected by climate change, with water quality in some also being degraded by forest fires.
Water scarcity and water-related risks will continue to increase in all regions assessed, with increased risk at higher levels of global warming. Global glacial mass loss is projected to reduce water availability for agriculture, hydropower, and human settlements in the medium to long term, with these changes expected to double if we reach 4°C warming.
Without adaptation, predicted increases in direct flood damage will be up to twice as high at 2°C and up to four times as high at 3°C compared to a global warming of 1.5°C. With a global warming of 4°C, about 10% of the global land area is expected to experience increases in both high and low extreme river flows at the same location.
Climate change risks to cities, towns and key infrastructure will increase rapidly with continued global warming. Between 3.3 and 3.6 billion people live in areas highly vulnerable to climate change. About 1 billion people living in low-lying cities and settlements will be exposed in the medium term to coastal-specific climate hazards in all scenarios without effective adaptation. Population exposed to coastal flooding will increase by about 20% if sea level rises 0.15m above 2020 levels and will double at 0.75m sea level rise and triple at 1 .4 m. Globally, more than $10 trillion in assets could be at risk from coastal flooding by the end of this century.
Climate change will add more and more pressure on terrestrial food production systems with each increase in warming. Some of the world’s current crop and livestock areas will become climatically unsuitable, with the problem particularly exacerbated in many regions near the equator. Indigenous and other already vulnerable groups are likely to be disproportionately affected by climate change.
Globally, urban infrastructure systems are increasingly vulnerable to the impacts and risks of climate change, especially in places experiencing rapid unplanned urbanization. Climate-related damage to transport and energy infrastructure is expected to represent a significant financial burden for many countries, with cascading effects on economies and societies.
Adaptation and resilient development to climate change
Adaptation is the planned and/or unplanned (or autonomous) process of adjusting to actual or expected climate change and can occur in both human and natural systems.
Around 60% of all adaptation responses documented since 2014 respond to water-related hazards such as droughts, floods and rainfall variability. Due to the pervasiveness of current and projected impacts of climate change on water, the IPCC considers water to be critical to future climate-resilient development.
Most human systems and many natural systems have vast opportunities for successful adaptation to climate change. However, even effective adaptation does not prevent all loss and damage. The effectiveness of adaptive responses decreases and the predicted risk increases with increasing warming. Many natural systems are already at or near the “hard” limits of their natural adaptive capacity.
Enabling conditions are essential to implement, accelerate and sustain the adaptation of human and natural systems. These include political commitment and monitoring, institutional frameworks, policies and instruments with clear objectives and priorities, better knowledge of impacts and solutions, mobilization and access to financial resources monitoring and evaluation, and inclusive governance processes. Equitable outcomes contribute to multiple benefits for health and well-being and ecosystem services, including for indigenous peoples, marginalized and vulnerable communities.
The need for a climate response
the contribution of the WGII the IPCC Sixth Assessment Report notes the profound impacts that many human and natural systems are already experiencing due to climate change. It provides a timely warning of the urgent need for climate-resilient development that combines mitigation of greenhouse gas emissions and adaptation to climate change, with effective responses to other vulnerabilities of human and natural systems. .
the Summary for Policymakers produced by WGII concludes by noting:
“The cumulative scientific evidence is unequivocal: climate change is a threat to human well-being and planetary health. future for all.”
How can Jacobs help its customers?
Jacobs offers an unparalleled range of climate change services. We have worked across the built environment, water, energy and transportation life cycle for over 75 years and understand the complexities of the climate change challenge on the ground. From strategy to implementation, our global team of advisors and technicians can work with local teams to help cities, infrastructure providers, utilities and communities respond to climate change through system transition. energy, decarbonization, adaptation and resilience, and improved environmental management.
Check out the full report here:
This last WGII report will be followed in April 2022 by the report of Working Group III on Climate Change Mitigation and later in 2022 by a global synthesis report.