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TED Talks Daily

How to see (and stop) deforestation from space | Tasso Azevedo

with Tasso Azevedo

Published November 17, 2025
View Show Notes

About This Episode

Land reformer Tasso Azevedo describes how the MapBiomas Network turns decades of satellite imagery into detailed, legally robust land-use maps to expose and curb deforestation in Brazil and other tropical regions. By integrating high-resolution imagery, property registries, and protected area data, the project has dramatically increased enforcement against illegal deforestation, redirected finance away from destructive operations, and supported a wide range of environmental and social applications. The talk also highlights successful action against illegal gold mining and outlines plans to expand this collaborative mapping approach to cover most of the world's tropical forests.

Topics Covered

Biodiversity loss Climate change activism Ecological data Environmental crime Sustainability Data-driven decision-making Nonprofit organizations Wildlife conservation Deforestation monitoring Satellite mapping

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Quick Takeaways

  • Brazil is the fifth largest greenhouse gas emitter, with about 75% of its emissions coming from land-use change, primarily deforestation, rather than fossil fuels.
  • The MapBiomas Network builds annual land-use maps from 1985 onward by mosaicking satellite images and using machine learning to classify each 30-by-30-meter pixel.
  • MapBiomas generates thousands of detailed deforestation reports per week that are precise enough to be used in court, greatly increasing enforcement against illegal clearing.
  • Major Brazilian banks have denied around $1.5 billion in finance to thousands of farms linked to deforestation detected by MapBiomas, redirecting funds to more sustainable operations.
  • These combined efforts helped reduce deforestation in the Brazilian Amazon by 54% over two years, avoiding about 500 million tons of CO2 emissions.
  • MapBiomas data is used beyond forest loss, including in disease prevention, water regulation, climate impact assessment, soil conservation, and the protection of indigenous land rights.
  • Using satellite mapping, the team located nearly 3,000 airstrips in three weeks to support operations that reduced illegal gold miners on indigenous lands by 90%.
  • MapBiomas is a collaborative network of more than 100 organizations and aims, with support from the Audacious Project, to cover 70% of the world's tropical forests.

Podcast Notes

Introduction to the fight against deforestation and MapBiomas

Framing deforestation as a critical issue

Talk introduced as a fight against deforestation in Brazil and beyond[2:56]
• The introduction notes that deforestation in Brazil had been largely invisible until initiatives like MapBiomas began making it visible as data and imagery
MapBiomas described as a collaborative mapping initiative[3:01]
• The initiative stitches together 40 years of satellite images into evidence that can be used almost in real time
• These maps produce courtroom-ready evidence by turning deforestation into clear, undeniable pixels tied to specific locations and times
Results framed as real and large-scale in terms of protecting the planet's lungs[3:17]
• The introduction states that the project has led to significant results in saving tropical forests, which are referred to as the planet's lungs

Opening visualization of tree loss in the Amazon

Quantifying tree loss in the Amazon over the last 12 months[3:46]
• Azevedo says that in every second in the last 12 months, almost 20 trees were cut down in the Amazon
Emotional framing of deforestation as a disaster for Brazil[3:11]
• He calls deforestation and degradation a kind of disaster for the people of Brazil
• He notes that Brazil is the only country in the world named after a tree, underscoring the symbolic importance of forests to the nation

Brazil's emissions profile and the role of land-use change

Brazil's greenhouse gas emissions context

Brazil is a major global greenhouse gas emitter[4:01]
• Azevedo states that Brazil is the fifth largest greenhouse gas emitter on the planet
Distinctive source of Brazil's emissions compared to top emitters[4:12]
• He notes that unlike the top four emitters, most of Brazil's emissions do not come from burning fossil fuels
• Instead, he explains that about 75 percent of Brazil's emissions come from the way land is used
Deforestation as the main component of land-use emissions[4:12]
• He says the majority of those land-use emissions result from forests being cut down

Tropical forests as the lungs of the Earth

Tropical forests likened to Earth's lungs[4:21]
• Azevedo references the common description of tropical forests as the lungs of the Earth
Consequences of losing tropical forests[4:19]
• He explains that forests essentially exhale carbon that has been stored for many decades once they are cut and degraded
• He emphasizes that once forests are gone, they no longer exist to absorb carbon or to maintain evapotranspiration that supports the planet's cooling system

Global tropical forest loss and degradation

Recent forest loss in major tropical forest countries

Scale of tropical forest loss in 2024[4:44]
• He states that in 2024, countries with the largest tropical forest areas, such as Brazil, Peru, Congo, and Indonesia, lost forest equivalent to the size of Rwanda

Main drivers of forest conversion and degradation

Conversion of forest to other land uses[4:54]
• He lists pasture, cropland, urban areas, and mining as destinations for converted forest land
Additional degradation pressures on forests[5:05]
• Forests are also suffering degradation due to logging, increased droughts, and wildfires

Need for understanding and digital mapping

Understanding what is happening on the ground is essential[5:15]
• Azevedo argues that to fight forest degradation, it is necessary to understand exactly what is happening on the ground
Maps and digital mapping as key tools[5:18]
• He says digital mapping can play a key role because maps have power, but only if they reflect what is truly happening on the land
• He adds that while global satellite technology lets us see the world in our hands, images alone are not enough without understanding context and change over time

Creation of MapBiomas and its mapping methodology

Challenges of detailed national land-use maps in the past

Previously, national-scale detailed maps were nearly impossible[5:52]
• He explains that until very recently, producing a detailed map for an entire country like Brazil was almost impossible because it was too costly and too slow

Founding of MapBiomas Network

Assembling a multidisciplinary expert group[6:05]
• In 2015, they brought together experts in remote sensing, computer science, and land use to reinvent how maps are produced and published
Naming and scope of MapBiomas[6:07]
• They called this initiative the MapBiomas Network
Speed of map production achieved by MapBiomas[6:19]
• Azevedo notes that they can now produce 40 years of maps in six months

Technical process of building time-series land-use maps

Creating mosaics of satellite images[6:26]
• They start by creating a mosaic of all existing satellite images for each year since 1985
Using machine learning to classify pixels[6:32]
• Machine learning algorithms are applied to classify each pixel into land-use classes such as forest, mangrove, cropland, and water
Combining layers into annual maps and a time series[6:48]
• The classified layers are combined to create an integrated land-use map for each year
• This collection of annual maps forms a time series that shows transformations of land use across decades

Resolution and coverage of the MapBiomas time machine

Describing the time machine concept[6:56]
• Azevedo describes the system as a kind of time machine where one can see every pixel's history over time
Pixel resolution and number of pixels[7:02]
• Each pixel is 30 by 30 meters, and there are 9.6 billion such pixels making up South Brazil in the dataset he references
Historical coverage of the time series[6:48]
• He says they can now see the history of everywhere in the country at any point over the last four decades
Transition to the question of impact[7:14]
• He poses the question of how this mapping capability can actually lead to change

From mapping to enforcement against illegal deforestation

Analogy to traffic enforcement cameras

Comparing deforestation monitoring to red-light cameras[7:30]
• Azevedo asks if the audience has ever crossed a red light and received a penalty email showing their license plate
• He explains that something similar can be done for deforestation using remote sensing technologies

Process of detecting and documenting deforestation events

Using high-resolution imagery for validation[7:37]
• Every time deforestation is detected in Brazil, they use high-resolution satellite imagery to validate precisely when and where it occurred
Cross-referencing with multiple datasets[7:46]
• They cross deforestation information with land cover maps, land property registries, catalogs of protected areas, and clear-cut authorizations
• This cross-referencing allows them to produce very detailed reports on each deforestation event

Scaling up enforcement reports

Comparison of report volumes between agencies and MapBiomas[8:04]
• In 2018, all environmental agencies in Brazil together produced fewer than 1,000 reports in a year
• By contrast, Azevedo notes that last year MapBiomas produced 2,000 such reports per week
Legal robustness of the reports[8:30]
• He states that these reports have granularity and precision sufficient for use in courts of law

Impact on enforcement actions over time

Increase in actions against illegal deforestation[8:32]
• Between 2009 and 2024, the share of environmental agency actions targeting illegal deforestation grew from 5 percent to 54 percent of all deforestation

Influencing financial flows and reducing deforestation

Banks using MapBiomas data in lending decisions

Denial of finance to properties linked to deforestation[8:43]
• Azevedo reports that in the last two years, major banks in Brazil denied 1.5 billion dollars in finance to 30,000 farms where deforestation was detected by MapBiomas
Redirecting funds to sustainable operations[9:00]
• He notes that the money withheld from deforesting farms went instead to more sustainable operations

Measured reduction in Amazon deforestation and emissions

Decline in deforestation rates[9:08]
• According to Azevedo, these actions, together with several other measures, enabled Brazil to decrease Amazon deforestation by 54 percent over the last two years
Estimated emissions avoided[9:22]
• He states that this reduction in deforestation will save approximately 500 million tons of CO2 emissions

Expanding uses of MapBiomas data beyond deforestation

Scale of data usage and user base

Number of users and applications[9:32]
• Azevedo notes that in the last year, more than 600,000 users accessed MapBiomas data
• He says these users applied the data in hundreds of different applications

Examples of applications for MapBiomas data

Public health and water management[9:42]
• The data is used for preventing tropical diseases and regulating water use
Climate and soil management applications[9:46]
• MapBiomas information helps assess climate change impacts and design soil conservation practices
Support for indigenous land rights[9:48]
• He mentions that the data is also used for protecting indigenous land rights

Case study: Tackling illegal gold mining using satellite mapping

Harms caused by illegal gold mining in the Amazon

Environmental and health impacts[9:44]
• Illegal gold mining is described as a huge problem that destroys land and pollutes water
• Azevedo notes that it also poisons indigenous people, highlighting serious health consequences

Government operation to remove gold miners from indigenous lands

Decision to act against illegal miners[10:05]
• In 2023, the Brazilian government decided to act to remove 30,000 gold miners from indigenous lands
Strategy of targeting airstrips[10:24]
• One key strategy was to shut down airstrips near mines in remote areas so miners could not transport gold out of the forest
• The intent was to make it difficult to move the gold, creating pressure for miners to leave

Mapping airstrips across the Amazon

Rapid identification of airstrips[10:34]
• To support this strategy, the MapBiomas team needed to locate the airstrips
• Within three weeks, they mapped almost 3,000 airstrips across the entire Amazon
Scale of the area covered[10:36]
• Azevedo notes that the Amazon region they mapped is an area the size of Europe

Outcome of actions against illegal miners

Reduction in gold miners on indigenous lands[10:05]
• As of the time of the talk, he states that the number of gold miners on indigenous lands had dropped by 90 percent

Collaborative nature of MapBiomas and future goals

Importance of collaboration in achieving impact

MapBiomas as a large collaborative network[10:56]
• Azevedo says that none of the achievements would be possible without applying a collaborative approach
• He describes the MapBiomas Network as a group of more than 100 organizations
Geographical scope of the network[10:56]
• These organizations work across South America and Indonesia

Expansion plans supported by the Audacious Project

Goal to expand coverage of tropical forests[11:18]
• With support from the community and the Audacious Project, they aim to increase their reach to cover 70 percent of the world's tropical forests by 2013, according to the talk

Vision for local mapping capacity in tropical countries

Empowering local map production for action[11:28]
• He states a belief that the ability and power to produce maps for action locally should exist in every tropical country
Aspirational closing image[11:36]
• Azevedo concludes by expressing hope that society can replace the sounds of destruction with the sounds of life in tropical forests

Host outro and contextual information about the talk

Details about the event and initiative

Talk venue and timing[12:12]
• The host identifies the talk as given by Tasso Acevedo at the TED Countdown Summit in Nairobi, Kenya in 2015
Connection to the Audacious Project[12:04]
• The host explains that this ambitious idea is part of the Audacious Project, TED's initiative to inspire and fund global change

Information about TED resources and production credits

Pointers to more TED information[12:10]
• Listeners are told they can learn more about the Audacious Project at audaciousproject.org and about TED's curation guidelines at ted.com slash curation guidelines
Podcast identification and production team[12:20]
• The host states that TED Talks Daily is part of the TED Audio Collective
• The talk is said to have been fact-checked by the TED Research Team and produced and edited by a team including Martha Estefanos, Oliver Friedman, Brian Green, Lucy Little, and others
Host sign-off[12:21]
• Host Elise Hugh signs off, saying she will be back the next day with a new idea for listeners

Lessons Learned

Actionable insights and wisdom you can apply to your business, career, and personal life.

1

Making complex environmental problems visible through clear, high-resolution data transforms them from abstract concerns into concrete, enforceable issues that institutions and citizens can act on.

Reflection Questions:

  • • Where in your work or life are important problems still invisible or poorly measured, and how could better data make them actionable?
  • • How might you redesign the way you present information so that decision-makers see specific, undeniable evidence rather than vague trends?
  • • What is one issue you care about where you could start gathering and organizing clearer data this month?
2

Combining multiple data sources-such as imagery, property records, and legal authorizations-creates powerful, cross-validated insights that are far more useful than any single dataset on its own.

Reflection Questions:

  • • What key data sources are currently siloed in your organization or projects that, if combined, could reveal new patterns or risks?
  • • How could integrating diverse information streams improve the accuracy and credibility of your decisions?
  • • What is one concrete step you could take this week to connect two existing datasets or perspectives you normally consider separately?
3

Aligning financial incentives with ethical and environmental performance can shift vast amounts of capital away from destructive activities and toward more sustainable ones.

Reflection Questions:

  • • In what ways do current incentives in your environment unintentionally reward short-term or harmful behavior?
  • • How could you design or advocate for criteria that tie access to resources-money, time, recognition-to responsible performance?
  • • What is one lever you control (budgets, approvals, partnerships) where you could start rewarding more sustainable or ethical choices?
4

Large-scale change on complex issues often requires broad collaboration across organizations and disciplines rather than isolated efforts.

Reflection Questions:

  • • Which challenges you face are too complex for a single team or organization to solve effectively on its own?
  • • How might partnering with experts from different domains accelerate your progress or uncover solutions you would not reach alone?
  • • What is one coalition, network, or partnership you could initiate or join in the next three months to tackle a shared problem?
5

Building local capacity to generate and use actionable information empowers communities and countries to take ownership of solutions rather than relying solely on external actors.

Reflection Questions:

  • • Where are you or your organization overly dependent on external expertise or tools instead of developing local skills and systems?
  • • How could you design your projects so that knowledge and capabilities remain with local teams after you leave?
  • • What is one training, tool, or process you could help establish that would enable others to act independently and effectively?

Episode Summary - Notes by Skylar

How to see (and stop) deforestation from space | Tasso Azevedo
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