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Carlos Nobre: “Carbon Sink to Carbon Source? How the Amazon Rainforest Could Become a Self-Drying Savanna”

November 14, 2024

(Conversation recorded on September 25th, 2024)

Show Summary

The Amazon Rainforest is one of the Earth’s most vital systems, playing a key role in maintaining the balance and stability of our climate. Yet this extraordinary ecosystem, which influences global rainfall patterns and regulates temperatures, is increasingly threatened by human activity. What is the current status of the ancient Amazon Rainforest, and how could its trajectory shape the entire planet for thousands of years to come?

In today’s episode, Nate speaks with Earth scientist Carlos Nobre to explore the critical challenges facing the Amazon. They delve into the rainforest’s unique ecological dynamics, the devastating impact of deforestation and wildfires on its ability to function, and how the health of the Amazon directly influences the climate of the entire world.

In what ways does the astounding biodiversity of the Amazon play critical roles in its resilience, and how is that biodiversity being put at risk? How could a system that has sustained its own water cycles for millions of years suddenly tip into a self-drying savanna? Finally, what actions should countries – beyond the Amazonia region itself – take to support the conservation and restoration of the world’s largest rainforest and the people that call it home?

About Carlos Nobre

Carlos A. Nobre is an Earth Scientist from Brazil, currently associated with the University of São Paulo. He is also the co-chair of the Science Panel for the Amazon-SPA. He obtained his PhD in Meteorology at MIT. Nobre’s work mostly focuses on the Amazon and its impact on the Earth System. He chaired the Large-Scale Biosphere-Atmosphere Experiment in Amazonia (LBA). He is a foreign member of the US National Academy of Sciences and the Royal Society, and member of the Brazilian Academy of Sciences and the World Academy of Sciences. He was awarded several prizes including the Volvo Environmental Prize, the AAAS Science Diplomacy Award and AAAS Fellow Award. He also developed the Amazonia 4.0 initiative, an innovative project to demonstrate the feasibility of a new socio-bioeconomy of standing forests and flowing rivers in the Amazon.

Show Notes & Links to Learn More

PDF Transcript

00:00 – Carlos Nobre info + works, Science Panel for the Amazon, Large-Scale Biosphere-Atmosphere Experiment, Amazonia 4.0

Amazon Assessment Report 2021

03:04 – National Institute of Amazonian Research

03:15 – 0.5% of the Amazon had been deforested in 1975 + more info on deforestation in the Amazon

06:46 – Evolution of the Amazon + more info

07:10 – Water recycling in the Amazon + more info

07:43 – Annual rainfall in the Amazon

08:19 – Rainforest transpiration during wet vs dry season + more info

12:15 – 150-200 billion tons of carbon stored in the Amazon + carbon cycle in the Amazon

14:27 – Impact of Amazon deforestation on rainfall, impact on global climactic events, impact on US climate

16:14 – *92% of sunlight is absorbed by the rainforest canopy

17:57 – Wildfires and drought in the Amazon

18:28 – Climate change and droughts in the Amazon

19:16 – Previous droughts + 2023/24 drought

19:45 – El Niño phenomenon + intensities

20:00 – El Niño and drought in the Amazon

20:45 – Amazon deforestation and climate change 1990 paper + 1991 paper

21:00 – Amazon deforestation figures

22:02 – 1990 IPCC report

22:50 – 2016 paper on tipping points in the Amazon

23:00 – Today 18% of the Amazon has been deforested

23:11 – We reached 1.5 degrees warming in 2023

23:32 – Increasing dry season length in the Amazon

24:05 – Forests’ role as carbon sinks

24:15 – The Amazon’s role as a carbon sink + more info

24:23 – The Amazon has become a carbon source

25:00 – 2024 paper: Critical transitions in the Amazon forest system

25:15 – Amazon forest degradation

27:58 – Amazon deforestation halved in 2023

28:35 – Amazon summit Belém

31:05 – August 2024 temperature record

32:10 – Current climate policies will lead to 2.5 degrees warming

33:02 – Military dictatorship in Brazil + Colonialism, dictatorship and deforestation 

34:40 – Fires caused by criminal activity + 90% of deforestation is illegal

35:50 – Satellite monitoring of deforestation in Brazil

36:55 – ‘Arcs of Restoration’ policy brief

38:36 – The cost of saving tropical forests

40:30 – Biodiversity in the Amazon: 16,000 tree species + 50,000 plant species

41:30 – Oropouche virus

42:03 – Pandemic risks from the Amazon

42:50 – The Amazon River

44:05 – Planetary tipping points + more info

44:10 – Johan Rockström + TGS Episode

44:20 – Permafrost collapse and carbon release

45:25 – 6th Mass Extinction + Has the Earth’s 6th Mass Extinction already arrived?

45:50 – Atmospheric CO2

46:15 – Corey Bradshaw + TGS Episode, impact of warming on extinctions

47:08 – Secondary forests + carbon sink potential of secondary forests in Brazilian Amazon

49:05 – Regenerative Agriculture

51:04 – The Amazon’s ‘flying rivers’

51:20 – Economics of Amazon reforestation

51:40 – Law preventing products causing deforestation from being sold in EU

52:49 – Profitability of agroforestry + more info

53:11 – Growth in global beef consumption

54:03 – IPCC on cutting out meat

55:40 – Environmental impact of beef consumption

56:57 – 65% of deforestation caused by cattle ranches

58:06 – Afro-descendent presence in the Amazon

59:20 – Peoples of the Amazon before european colonization

1:00:00 – Indigenous population in Brazil over time

1:00:10 – The Amazon is home to *1.5 million indigenous people

1:01:15 – Sonia Guajajara

1:01:30 – Brazil’s congress pushing against indigenous land rights + more info

1:03:16 – Amazon Creative Labs: Cupuacu-Cacau

1:05:57 – Amazon Institute of Technology + more info

1:08:15 – Planetary Guardians + Planetary Boundaries

Nate Hagens

Nate Hagens

Nate Hagens is the Director of The Institute for the Study of Energy & Our Future (ISEOF) an organization focused on educating and preparing society for the coming cultural transition. Allied with leading ecologists, energy experts, politicians and systems thinkers ISEOF assembles road-maps and off-ramps for how human societies can adapt to lower throughput lifestyles.

Nate holds a Masters Degree in Finance with Honors from the University of Chicago and a Ph.D. in Natural Resources from the University of Vermont. He teaches an Honors course, Reality 101, at the University of Minnesota.