Climate Science: Crash Course History of Science #45

Summary

The video explores the history of climate science, from early predictions by Guy Callendar to modern debates about the Anthropocene and climate change. It discusses pivotal discoveries like the Keeling Curve, the Great Acceleration of industrial growth, and the ethical dilemmas of geoengineering and responsibility for climate change. Highlighting both scientific progress and the political pushback, the video emphasizes how the creation and suppression of knowledge have shaped environmental policy. It concludes by reflecting on the moral and technical challenges faced by scientists as they work toward solutions in an increasingly disrupted world.

Takeaways

• 😀 The *Blue Marble* image, taken in 1972, symbolizes not just space exploration but also the environmental movement on Earth, showing the planet as a small, interconnected orb in space.
• 🌍 Earth, although seeming vast when standing on it, is seen as a tiny, fragile speck when viewed from space, inspiring reflection on its fragility and interconnectedness.
• 🌱 Human activity, fueled by booming populations and technological advancements like air travel and the internet, is shrinking Earth's green spaces and causing environmental degradation.
• 🔬 Climate science took time to develop, with early skeptics of the idea that rising carbon dioxide levels could affect the global climate, but pioneering work by scientists like Guy Callendar and Charles Keeling proved otherwise.
• 📈 The Keeling Curve, based on CO2 measurements at Mauna Loa Observatory starting in 1958, clearly shows the rise in CO2 levels over time, correlating with the warming of the planet.
• 🌍 The term *Anthropocene*, the 'Age of Humans', describes the era of significant human impact on Earth's systems, though its exact starting point is still debated among scientists.
• ⚖️ The debate over the Anthropocene includes discussions about when human influence on the planet truly began, with events like the Industrial Revolution and atomic bomb tests being potential starting points.
• 🌊 The Planetary Boundaries framework outlines nine key natural processes (e.g., climate change, ocean acidification, and biodiversity loss) that humanity must stay within to maintain Earth’s habitability.
• 🛑 Despite overwhelming scientific consensus on climate change, fossil fuel companies have used tactics similar to the tobacco industry to spread doubt and deny the science behind climate change.
• ⚙️ The moral and technical questions surrounding climate science include who should bear the cost of addressing climate change, with debates around geoengineering and global responsibility for the planet's future.
• 🌍 The history of climate science is increasingly focused on understanding not only the problems of climate disruption but also the solutions, including the ethics of how to tackle global-scale issues.

Q & A

What is the significance of the Blue Marble image?

The Blue Marble, taken during the Apollo 17 mission in 1972, symbolizes both space exploration and the environmental movement. It portrays Earth as a fragile, small, and isolated planet, reminding us of the vulnerability of our ecosystems.

How did the perception of Earth's size change over time?

Earth seemed large and solid when experienced from the ground. However, as technology like air travel and the internet advanced, and the human population grew, Earth began to feel smaller and more interconnected.

Why was climate science slow to recognize human-caused climate change?

Scientists were initially cautious and conservative in their claims. The scientific community was highly specialized by the 1900s, which made it challenging to address complex global phenomena like climate change. The difficulty of studying global patterns with regional data also contributed to the slow recognition.

What role did Guy Callendar play in early climate science?

In 1938, Guy Callendar was one of the first to propose that rising CO2 concentrations were responsible for global warming. He used 19th-century temperature measurements and CO2 data to make this prediction, though it was met with skepticism at the time.

What is the Keeling Curve and why is it important?

The Keeling Curve is a graph of CO2 levels in the atmosphere, based on measurements taken at Mauna Loa Observatory starting in 1958. It shows a clear upward trend in CO2 concentrations and a seasonal variation, providing crucial evidence that the planet is warming and CO2 is rising.

What is the Anthropocene, and why is it controversial?

The Anthropocene refers to the proposed 'Age of Man,' marking a period of significant human impact on the Earth’s geology and ecosystems. It is controversial because historians and scientists debate the exact starting point, with some suggesting alternative terms like 'Capitalocene' or 'Chthulhucene' to highlight different aspects of human influence.

What are some potential markers for the beginning of the Anthropocene?

Some key markers include the Industrial Revolution's coal usage, the atomic bomb tests starting in 1945, the rise of plastics after the 1960s, and the 'Great Acceleration' in human population growth and resource consumption. Each represents a significant shift in Earth's physical and environmental conditions.

How do chicken bones fit into the Anthropocene debate?

Chicken bones have been proposed as a potential marker for the Anthropocene due to the overwhelming number of chickens (more than 23 billion at any given time). Their dominance on the planet’s fossil record, shaped by human intervention, could signify humanity’s major influence on Earth’s ecosystems.

What is the Planetary Boundaries framework?

The Planetary Boundaries framework outlines nine critical natural processes, such as climate change, ocean acidification, and biodiversity loss, within which humanity can safely operate. These boundaries are designed to help guide sustainable human activities to avoid irreversible environmental damage.

What is climate change denial and how did it emerge?

Climate change denial refers to the spread of doubt about the scientific consensus on climate change, despite overwhelming evidence. It emerged when fossil fuel companies used the same public relations strategies as tobacco companies to discredit climate science, as documented by Naomi Oreskes and Erik Conway in 2010.

What moral and political issues are tied to climate change science?

Key moral questions include who should bear the cost of addressing climate change. Should it be the countries or corporations most responsible for emissions, or should it be a shared global responsibility? These issues reflect the intersection of science, politics, and ethics in addressing the impacts of climate change.