The Tipping Points of Climate Change — and Where We Stand | Johan Rockström | TED

The Urgency of Climate Change: A Scientific Assessment

Current State of the Planet

• Earth system and climate scientists express growing concern over rapid changes in the planet's climate, which are occurring faster than anticipated.

• The planetary boundary framework was introduced 15 years ago to assess Earth's stability through nine critical processes; this framework remains vital today.

• As we reach the halfway point of the decisive decade for climate action, a scientific report reveals that global mean surface temperature has risen by 1.2°C, marking the highest level in 100,000 years.

Acceleration of Warming

• There is an alarming acceleration in warming trends: from 1970 to 2010, temperatures rose by 0.18°C per decade; since 2014, this rate increased to 0.26°C per decade.

• If current trends continue, projections indicate a potential rise to over 2°C within two decades and possibly reaching 3°C by the year 2100.

Economic and Social Impacts

• The consequences of climate change are manifesting as significant economic burdens on societies worldwide due to extreme weather events like droughts and floods.

• In just one year (2023), human-induced climate change has been linked to approximately 12,000 deaths and $200 billion in costs in the U.S. alone.

Future Projections

• Current trajectories suggest an estimated loss of up to 18% of global GDP by 2050 if no substantial changes are made—equating to a staggering $38 trillion annually.

• Historical context shows that civilization has thrived at around +14°C; exceeding these limits poses unprecedented risks.

Buffering Capacity and Tipping Points

• Scientists highlight concerns regarding Earth's buffering capacity—the ability to absorb shocks like greenhouse gas emissions—and its diminishing effectiveness.

• Evidence indicates that major carbon sinks such as forests are losing their ability to sequester carbon effectively due to ongoing environmental stressors.

Oceanic Changes and Unknown Factors

• The ocean currently absorbs about 90% of heat from human-induced climate change; however, recent data shows concerning increases in sea surface temperatures beyond historical norms.

• While El Niño may contribute to rising temperatures, there is uncertainty surrounding other factors causing drastic changes observed in early 2023.

The Ocean's Alarm: Are We Pushing the Planet Beyond Its Limits?

The Current State of the Ocean

• The ocean is losing resilience and may begin releasing heat to the atmosphere, potentially leading to self-amplifying warming.

• There is concern about whether we are pushing the planet out of its stable Holocene state into a "hot house Earth" scenario.

Tipping Points in Climate Systems

• Key systems like the Greenland ice sheet, North Atlantic overturning, coral reefs, and Amazon rainforest are identified as tipping elements that could flip from stabilizing to destabilizing states.

• Sixteen climate tipping element systems have been mapped; their interconnections through oceanic cascades are crucial for global stability.

Risk Assessment of Tipping Points

• For the first time, attempts have been made to quantify temperature thresholds at which these systems may tip.

• Five out of sixteen systems could cross their tipping points at just 1.5°C rise in temperature, including significant ice sheets and coral reef systems.

Historical Context and Future Projections

• Over 30 years, scientific assessments show that risk levels for tipping points have decreased from 5°C to between 1.5°C and 2°C.

• The Amazon rainforest faces a high risk of irreversible change at temperatures between 3°C to 5°C but can tip at lower temperatures if deforestation exceeds critical thresholds.

Urgency for Action

• Currently at approximately 1.2°C rise with significant deforestation already occurring; urgent action is needed to prevent crossing critical thresholds.

• To stay under a 1.5°C increase, humanity has only about 200 billion tons of CO2 left in its carbon budget while current emissions stand at around 40 billion tons per year.

Pathways Forward

• Immediate emission reductions of at least 7% annually are necessary for a safe transition towards net-zero by 2050.

• Acknowledgment that even with successful mitigation efforts, overshoot beyond the 1.5°C limit is likely between 2030 and 2035 due to existing greenhouse gas concentrations.

Implications of Overshoot

• Expect more extreme weather events (droughts, floods), with current conditions viewed as mild compared to future scenarios.

Climate Crisis: A Call for Exponential Change

The Challenge of Climate and Biodiversity

• The stability and resilience of the planet's climate, biodiversity, and essential resources like nitrogen, phosphorus, land, fresh water, air pollutants, and chemicals are critical challenges. Achieving the 1.5°C target of the Paris Agreement requires more than just phasing out fossil fuels; it necessitates returning to a safe operating space within nature-based boundaries.

Urgency for Transformation

• Scientific evidence indicates that we have reached a pivotal point regarding both risks and opportunities in transforming our world towards a sustainable future. The window for action is rapidly closing but remains open enough to inspire hope.

Need for Exponential Change

• Linear change is insufficient; only exponential change can meet the urgent demands of our time. Speed and scale are now the most crucial currencies in addressing climate issues.

Global Stewardship Responsibility

• There is an urgent need to recognize our interconnectedness at local and global levels. We must take on the responsibility of governing the entire planet to secure a viable future for coming generations.

Solutions Exist

• Solutions to address planetary crises are available and practical. Key transformations include:

• Rapid transition away from fossil fuels.

• Adoption of circular business models.

• Shift towards healthy diets supported by sustainable food systems.

• Halting loss of nature while scaling regeneration efforts across various ecosystems.

Positive Outlook Amidst Challenges

• Despite daunting challenges ahead—such as needing to cut global emissions by half by 2030—there remains optimism due to:

• Evidence showing that citizens worldwide care about climate issues.

• Trust in climate science among the public.

Implementing Available Solutions