Environmental science Unit 3

Deforestation 

Conversion of forest to other land use 

Types of deforestation

• Agriculture 

• Grazing livestock 

• Urban development 

One of the most pressing challenges globally

Deforestation

Total forest areas of about 4.1 billion hectares 

31% of total global land area 

Tropical forests distribution

Have the largest share of the world’s forests; 45% of the total 

More than half (54%) of the world’s forest 

Are concentrated in just 5 countries 

Tropical forests

• Some of the most biodiverse ecosystems on Earth 

• Typically have over half of the planet’s known plant and animal species 

A single hectare in the tropical forest

May host more than 650 tree species, surpassing the combined count in Canada and U.S 

Why tropical rainforests are important

• Habitat for organisms 

• Store carbon and release O2 

• Vital ecosystem regulators 

• Moderate air temperatures 

• Regulate atmospheric humidity 

levels through evapotranspiration 

• Regulate rate at which rainfall 

enters streams 

• Protect underlying soil from 

erosion 

• Plant and animal resources for 

direct human benefit 

• Home to ~150 million native and 

indigenous peoples worldwide 

Forest decline

• Accelerated over the past 6 decades 

• Difficult to estimate rate of decline 

Food and Agriculture Organization of the United Nations  

Estimates an annual loss of 14 million hectares per year in the 1980s  

Brazilian rainforest 

• Crucial carbon sink 

• Critical ecosystem for water cycling and global climate regulation

The amazon from slash and burn deforestation 

Is now emitting as much carbon dioxide as it absorbs 

Why was there a steep decline in deforestation post-2004 

• Falling commodity prices 

• Increased enforcement efforts 

• Government conservation initiatives

In 2004, Assertive policy by Brazil’s government 

Established national and state parks, creation of protected territories for indigenous communities, reinforcement of environmental enforcement agencies, imposition of stricter regulations on the exportation of goods originating from illegally deforested areas, and enhancement of satellite monitoring systems 

In 2008, Establishment of the Amazon Fund 

Initiative to assist in lowering high deforestation rate by providing financial support for sustainable livelihoods for over 30 million inhabitants of the Amazon basin 

One of the first projects of the UN’s REDD+ program 

Reducing emissions from deforestation in developing countries; significant funding from Norway and Germany 

When did deforestation escalate again? 

In 2012

Why did deforestation escalate in 2012 

• Administration favored agribusiness interests 

• Norway and Germany halted payments to the Amazon Fund 

Brazilian rainforest in the 2024 

Deforestation was at its lowest rate in 6 years  

Current Brazilian administration 

Pledges to end deforestation in the Brazilian Amazon once and for all 

Fragmentation 

• Areas of forest become isolated after clearance, leading to plants and animals being cut off from the larger ecosystem 

• Creates more miles of edges between cleared and intact forest areas 

• Facilitates human access to the forest for further clearing and logging activities 

Fishbone/herringbone pattern 

Affects biodiversity 

New York Declaration of Forest (NYDF) 

• Coalition consisting of governments, corporations, civil society, and indigenous peoples’ organizations; first established at UN Climate Summit in 2014 

• Wanted to half deforestation in half by 2020 

• Projected reduction of carbon pollution by ~4-8 billion tons annually, equivalent to current emission of the United States and India combined 

Beef cattle production

Accounts for more than ¾ of deforested territory in Brazil

Tropical forest worldwide

Accounts for ~70% loss annually from beef cattle

Inefficient industry beef cattle

Not great at converting solar energy into food

Beef cattle production is concentrated in mostly 4 countries

Argentina, Paraguay, Colombia, and Brazil

Beef cattle exceeds deforestation

By more than 5 times

Soy bean production

Predominantly concentrated in three nations: United States, Brazil, and Argentina

What is soy used for

To feed pigs, chickens, dairy cows, farmed fish, vegetable oil,, and biodiesel

Palm oil production

Grown in large monoculture plantation concentrations in Indonesia and Malaysia

Pal oil is used in…

Processed foods, personal care products, chocolate, shampoo, biofuel, vegetable oil

Palm oil production has caused catostrophic decline in primary forest area

Biodiversity on rich Island of Borneo

Species impact of palm oil production

• Orangutans

• Clouded Leopards

• Pygmy Elephants

Subsistence farmers

• Impoverished

• Venture into already degraded rainforest territories and establish small-scale farming operations

• Only use what is necessary to sustain their families

Major challenge for subsistence farmers

Soil is unsuitable for sustainable farming practices; once cleared, rainfall rapidly washes away soil nutrients, causing the soil fertility to decline quickly

Farmers abandon their fields

After 2-3 years of cultivation, they relocate to the deeper part of the forest where they repeat the process

Wood products

Contribute to ~10% of the global forest loss

Wood pulp

Used in paper production

Wood timber

For construction and furniture

Commercial logging

Extraction of trees for profit either as timber or pulp

Selective logging

Targets only economically valuable species; can potentially harm 10-20 nearby trees

Clearcutting

Cutting down all trees in an area

Heavy machinery (Bulldose, road grader, log skidders)

Results in significant damage to the forests, similar to harm cause by chainsaws to individual trees

Biodiversity

Variety of living organisms along with their distributions and patterns; diversity of life has evolved over billions of years through natural processes; significantly influenced by humans

• Includes species, genetic, and ecosystem diversity

Current named species on Earth

2.2million (half ar insects)

Global species count range

2-8million species

Largely unexplored organisms

• Fungi

• Groundworms

Could be up to a million undiscovered species residing where?

The ocean floor and other hard to acess areas

Political instability

Restricts exploration, preventing researchers from entering