Sounding the Climate Change Alarm: Lessons from Carl Sagan
The Visionary Thinker
Carl Sagan, the renowned astronomer and science communicator, was one of the early voices to sound the alarm on global warming. His concerns were rooted in his work on planetary atmospheres, particularly the study of Venus and its runaway greenhouse effect.
Sagan's interest in Venus began in the early 1960s when he and other scientists were trying to understand why Venus was so much hotter than Earth. His 1960 publication, “The Radiation Balance of Venus,” laid the groundwork for future research on Venus’ atmosphere and climate and helped understand that Venus's dense atmosphere was responsible for its extreme temperatures. The carbon dioxide (CO2) traps the sunlight that reaches the planet's surface, causing the surface temperature to rise—a process that feeds on itself and results in a runaway greenhouse effect. This discovery not only advanced our understanding of planetary climates but also paved the way for more space missions to study Venus.
Connecting Venus to Earth
The doors of heaven and hell are adjacent and identical. —Nikos Kazantzakis, The Last Temptation of Christ.
Sagan was deeply concerned about the implications of his findings for Earth. He argued that studying other planets, like Venus, could serve as a warning for Earth. Understanding how Venus transformed into such an inhospitable world could help us take steps to prevent Earth from suffering a similar fate.
In the late 1970s and 1980s, Sagan began publicly discussing the implications of increasing CO2 levels in Earth's atmosphere. He made comparisons between the greenhouse effect on Venus and the potential for a similar, though less extreme, scenario on Earth, stressing the risks of the continuous burning of fossil fuels, which increases the concentration of CO2 and other greenhouse gases in the atmosphere.
Sagan was a remarkable science communicator. His 1980 TV series, Cosmos: A Personal Voyage, was a groundbreaking journey through science, space, and the universe, becoming one of the most viewed and influential science TV series ever. Sagan’s ability to explain complex scientific concepts in an understandable manner helped to raise public awareness about the risks of climate change and laid the foundation for the environmental movement and ongoing scientific research into climate change.
In his 1981 book, Cosmos, Carl Sagan wrote:
“Like Venus, the Earth also has a greenhouse effect due to its carbon dioxide and water vapor. … The surface of Venus is a warning: something disastrous can happen to a planet, rather like our own. The possibility of a runaway greenhouse effect suggests that we have to be careful. Even a one- or two-degree rise in global temperature can have catastrophic consequences.”
Global Warming Warnings from 1980: Have We Made Progress or Fallen Behind?
In an episode of "Cosmos" (video above) titled "Heaven and Hell," Sagan discussed the dangers of global warming and proposed four key actions:
More efficient use of fossil fuels
Research and Development in safe, alternative energy resources, with a focus on solar power.
Reforestation on a grand scale
Helping to bring the billion poorest people on the planet to self-efficiency.
These recommendations, made nearly 45 years ago, remain relevant today. Despite global efforts addressing each of these four areas, we find ourselves in a worse position than when Sagan first voiced his concerns.
Significant advancements in energy efficiency have been made across various sectors, including transportation, industry and residential energy use. However, global energy demand continues to rise, partly due to population growth and economic development, particularly in emerging economies.
While the development and deployment of renewable energy have progressed rapidly, these sources still account for a relatively small fraction of global consumption. The intermittent nature of solar power and the need for large-scale energy storage solutions are ongoing challenges.
There have been many reforestation and afforestation initiatives worldwide, such as the Bonn Challenge and the African Forest Landscape Restoration Initiative (AFR100). However, deforestation, especially in tropical regions such as the Amazon and Southeast Asia, often undermines these efforts. Land use conflicts, particularly between agriculture and forest restoration, add to the challenges.
Lastly, fighting poverty remains a critical challenge. Ambitious programs like the United Nations' 2030 Agenda for Sustainable Development, have been initiated, aiming to end poverty and improve health and education while tackling climate change. However, the global population has surged by over 3 billion people since 1980, from around 4.4 billion to over 8 billion today. This increase has intensified the demand for energy, food, water, and other resources, and complicated efforts to end poverty and mitigate climate change.
A Call to Action: The Senate Hearing of 1985
On December 10, 1985, politicians and scientists, including Carl Sagan, Al Gore, and Syukuro Manabe, testified at a Senate hearing about the potential dangers of climate change. The hearing was part of a broader examination by the House of Representatives Committee on Energy and Natural Resources, specifically focusing on the issue of the “Greenhouse Effect” and its potential impact on climate change.
In his testimony, Carl Sagan warned that the continued increase in greenhouse gases could lead to significant global warming and he predicted a range of serious consequences: rising sea levels due to the melting of polar ice caps, shifts in agricultural patterns, more frequent and severe weather events and widespread ecological disruptions. Today, we’re witnessing many of these warmings becoming reality. Sea levels are rising, extreme weather events like hurricanes and heat waves are becoming more frequent and intense, and there is growing concern over tipping points arising in ecosystems because of the crossing of environmental thresholds.
In his testimony, Sagan emphasized the need for a global shift in perspective
“The nations have to make a change. From the traditional concern about themselves to that about the planet and the species, a change from the traditional short-term objectives to long-term objectives. We need to develop a global conscience—a view that transcends our exclusive identifications with the generational and political groupings into which we have accidentally been born. The solution to this problem requires a perspective that embraces the planet and the future because we are all in this greenhouse together.”
The Anthropocene: The Era That Humans Are Messing Up Big Time
While Carl Sagan did not use the term "Anthropocene"—a concept that was formally proposed in 2000 by Paul Crutzen and Eugene Stoermer—his insights and warnings about human impact on the planet certainly resonate with the themes of the Anthropocene, the geological epoch that recognises that human activities have a dominant influence on the environment, climate and ecology of the Earth. He wrote:
We, humans, now represent a new and perhaps decisive factor. Our intelligence and our technology have given us the power to affect the climate. How will we use this power? Are we willing to tolerate ignorance and complacency in matters that affect the entire human family? Do we value short-term advantages above the welfare of the Earth? Or will we think on longer time scales, with concern for our children and our grandchildren, to understand and protect the complex life-support systems of our planet? The Earth is a tiny and fragile world. It needs to be cherished. – Carl Sagan, Cosmos
Despite warnings from scientists like Carl Sagan, politicians in the 1980s failed to take the necessary actions to address climate change. The President of the United States at the time, Ronald Reagan, was a strong supporter of the fossil fuel industry, and he strongly promoted domestic oil, gas and coal production. Given the powerful lobbying of the fossil fuels industries, it was unlikely that his administration would impose stricter environmental regulations on these industries.
Another reason was the complexity and understanding of the problem. While the basic science of climate change was well-established by the 1980s, uncertainties about the timing, magnitude, and regional impacts of climate change remained. Many politicians struggled to fully grasp the problem or underestimated its severity, given that the most severe impacts were projected to occur decades in the future.
A statement by the Republican Senator Dave Durenberger, who chaired the subcommittee on December 10, 1985, highlights the challenge of grasping the full implications of climate change. He said: ''One of the frustrations of dealing with this issue is that it is virtually beyond the grasp of human imagination. Despite what the best scientific minds in the world tell us, our instinct is to reject them out of hand.''
It is a sentiment that remains highly relevant today, particularly in the context of how politicians and society deal with complex scientific and technological issues. In a world that is evolving rapidly and growing more uncertain and difficult to control, addressing complex issues like climate change, cybersecurity, and artificial intelligence requires informed and forward-thinking leaders and citizens. To ensure the well-being and security of everyone in this increasingly complex environment, we need decision-makers capable of navigating these challenges with insight and foresight.
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