Earth Day was established in response to pollution by a liquid fossil fuel — a “well blowout” forty -five years ago at a new Union Oil drilling platform in the Pacific Ocean near Santa Barbara, California. Television coverage of the rapidly spreading oil slick and especially of oil coated sea birds provided vivid images that caught public attention. As more fully described in Earth Day 1970, pollution and population were considered the major environmental threats on early Earth Days. Climate change has since become the over-riding environmental threat, and our greatest threat, but it also must be remembered that the largest marine oil spill occurred 40 years after the Santa Barbara spill when the Deepwater Horizon oil drilling platform exploded in the Gulf of Mexico.
While substantial progress has been made in reducing the pollution of our lands and inland waters, we have largely neglected the emission of greenhouse gases into the atmosphere. The science of carbon dioxide as a greenhouse gas dates to the 1850’s, but it was not until the 1950’s that scientists began warning about global warming (the cause) and climate change (the effect). Science in the 1950’s and 60’s lacked the essential tools to observe, analyze and model global conditions; primarily satellites to observe; computers to analyze, model and communicate. By the 1980’s climate change science had gain the support of the vast majority of scientists.
In 1988 the Intergovernmental Panel on Climate Change (IPCC) was formed by the World Meteorological Organization and the United Nations Environmental Programme, with the objective of “providing governments at all levels with scientific information that they can use to develop climate policies”. The IPCC currently has 195 member nations, with thousands of people contributing to the work of the IPCC. The IPCC does not conduct any research, rather it relies on volunteer scientists to review published scientific papers and prepare several several categories of reports. The largest reports are the “Assessment Reports” which have been on eight-year cycles, with each Assessment producing four reports, three from “working groups” covering the physical science of climate change, the impacts of climate change and to adapt to them, and was of reducing greenhouse gas emissions, and a final synthesis report which draws of the 3 working group reports to produce one comprehensive overview. The synthesis report from the current cycle (AR6) is just being released.
The full volume “AR6” Synthesis Report is not available at the time of this writing, but the “Summary for Policymakers” which presents 21 “statements of fact” drawn from the three Working Group reports, along with an assessment of confidence; and organized into 3 sections. Selected “statements of facts” follow:
A. Current Status and Trends
A.1 Human activities, principally through emissions of greenhouse gases, have unequivocally caused global warming, with global surface temperature reaching 1.1°C above 1850–1900 in 2011–2020. Global greenhouse gas emissions have continued to increase, with unequal historical and ongoing contributions arising from unsustainable energy use, land use and land–use change, lifestyles and patterns of consumption and production across regions, between and within countries, and among individuals (high
confidence).
A.2 Widespread and rapid changes in the atmosphere, ocean, cryosphere and biosphere have occurred. Human–caused climate change is already affecting many weather and climate extremes in every region across the globe. This has led to widespread adverse impacts and related losses and damages to nature and people (high confidence). Vulnerable communities who have historically contributed the least to current climate change are disproportionately affected (high confidence).
A.3 Adaptation planning and implementation has progressed across all sectors and regions, with documented benefits and varying effectiveness. Despite progress, adaptation gaps exist, and will continue to grow at current rates of implementation. Hard and soft limits to adaptation have been reached in some ecosystems and regions. Maladaptation is happening in some sectors and regions. Current global financial flows for adaptation are insufficient for, and constrain implementation of, adaptation options, especially in developing countries (high confidence).
A.4 Policies and laws addressing mitigation have consistently expanded since AR5. Global GHG emissions in 2030 implied by nationally determined contributions (NDCs)* announced by October 2021 make it likely that warming will exceed 1.5°C during the 21st century and make it harder to limit warming below 2°C. There are gaps between projected emissions from implemented policies and those from NDCs and finance flows fall short of the levels needed to meet climate goals across all sectors and regions. (high confidence) *[NDC – Nationally Determined Contribution, the emission reductions voluntarily pledged by individual nations].
B. Future Climate Change, Risks, and Long–Term Responses
B.1 Continued greenhouse gas emissions will lead to increasing global warming, with the best estimate of reaching 1.5°C in the near term in considered scenarios and modelled pathways. Every increment of global warming will intensify multiple and concurrent hazards (high confidence). Deep, rapid, and sustained reductions in greenhouse gas emissions would lead to a discernible slowdown in global warming within around two decades, and also to discernible changes in atmospheric composition within a few years (high confidence).
B.2 For any given future warming level, many climate–related risks are higher than assessed in AR5, and projected long–term impacts are up to multiple times higher than currently observed (high confidence). Risks and projected adverse impacts and related losses and damages from climate change escalate with every increment of global warming (very high confidence). Climatic and non–climatic risks will increasingly interact, creating compound and cascading risks that are more complex and difficult to manage (high confidence).
B.3 Some future changes are unavoidable and/or irreversible but can be limited by deep, rapid and sustained global greenhouse gas emissions reduction. The likelihood of abrupt and/or irreversible changes increases with higher global warming levels. Similarly, the probability of low–likelihood outcomes associated with potentially very large adverse impacts increases with higher global warming levels. (high confidence)
B.7 If warming exceeds a specified level such as 1.5°C, it could gradually be reduced again by achieving and sustaining net negative global CO2 emissions. This would require additional deployment of carbon dioxide removal, compared to pathways without overshoot, leading to greater feasibility and sustainability concerns. Overshoot entails adverse impacts, some irreversible, and additional risks for human and natural systems, all growing with the magnitude and duration of overshoot. (high confidence)
C. Responses in the Near Term
C.1 Climate change is a threat to human well–being and planetary health (very high confidence). There is a rapidly closing window of opportunity to secure a liveable and sustainable future for all (very high confidence). Climate resilient development integrates adaptation and mitigation to advance sustainable development for all, and is enabled by increased international cooperation including improved access to adequate financial resources, particularly for vulnerable regions, sectors and groups, and inclusive
governance and coordinated policies (high confidence). The choices and actions implemented in this decade will have impacts now and for thousands of years (high confidence).
C.2 Deep, rapid and sustained mitigation and accelerated implementation of adaptation actions in this decade would reduce projected losses and damages for humans and ecosystems (very high confidence), and deliver many co–benefits, especially for air quality and health (high confidence). Delayed mitigation and adaptation action would lock–in high–emissions infrastructure, raise risks of stranded assets and cost–escalation, reduce feasibility, and increase losses and damages (high confidence). Near–term actions involve high up–front investments and potentially disruptive changes that can be lessened by a range of enabling policies (high confidence).
C.3 Rapid and far–reaching transitions across all sectors and systems are necessary to achieve deep and sustained emissions reductions and secure a liveable and sustainable future for all. These system transitions involve a significant upscaling of a wide portfolio of mitigation and adaptation options. Feasible, effective, and low–cost options for mitigation and adaptation are already available, with differences across systems and regions. (high confidence)
C.6 Effective climate action is enabled by political commitment, well–aligned multilevel governance, institutional frameworks, laws, policies and strategies and enhanced access to finance and technology. Clear goals, coordination across multiple policy domains, and inclusive governance processes facilitate effective climate action. Regulatory and economic instruments can support deep emissions reductions and climate resilience if scaled up and applied widely. Climate resilient development benefits from drawing on diverse knowledge. (high confidence)
All of the above, and excluded “statements of fact”, are followed by supporting information in the report and together with the full report when published will provide a comprehensive, and up to date description of our climate change status and scientific knowledge. Prepared by a global assembly of scientists, 6636 review comments from agencies of 47 national governments Assessment Report 6 was a major international undertaking. Its’ words should be heeded by all appropriate parties.
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”If we don’t do the right thing now, our children and grandchildren will have to face serious global problems”, Dr. Carl Sagan, a brilliant astrophysicist and “explainer of science” addressing the U.S Senate Subcommittee on Toxic Substances and Environmental Oversight, December 11, 1985.
