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Deforestation

The Carbon Question

Illegally deforested land in the Brazilian state of Para.

Illegally deforested land in the Brazilian state of Para. Most deforestation in Brazil happens to clear land for cattle ranching and soya plantations.


Why should we worry about deforestation?

Plants use photosynthesis to trap energy from sunlight, and in doing so they remove carbon from the atmosphere and incorporate it into their biomass. Forests are one of the main carbon dioxide sinks on the planet, but much of that carbon is released when they are cut down. Exposed soils also release carbon dioxide more rapidly than forest soils.

Burning carbon sinks like fossil fuels and timber means that stored carbon is released into the air as carbon dioxide (along with other gases such as methane). Studies of ancient air bubbles in Antarctic ice show that current levels of these gases are higher in the atmosphere now than at any time in the last 650,000 years (Siegenthaler et al, 2005). It is said that the loss of 20-30 percent of forest cover by 1990 is responsible for nearly 45 percent of the increase in atmospheric CO2 observed since 1850 (Malhi et al, 2002).

Aerial footage of illegally deforested land.

There is now a broad scientific consensus that the increased level of carbon dioxide in the atmosphere is contributing to a warming of the earth's atmosphere. Average temperatures rose by 0.76% during the 20th century. As a result, ice is melting in polar seas, glaciers, soils, rivers and lakes and resulting in seasonal changes to ecosystems; up to 50 percent of the species studied worldwide have been affected by climate change (Parmesan, C, and G Yohe, 2003) and human lives are perhaps already affected by changes in weather patterns, seasonality, water availability and temperature.


What research is there in the Amazon?

Bruce visited the Largescale Biosphere Atmosphere Research Centre (LBA), which is in primary Amazon rainforest some two hours drive north of Manaus. At this research base over 1,000 scientists come to investigate the different values of the forest environment.

As Bruce says: "If it can be proven unequivocally that the forest is worth something left standing, then the facts will be there to change people's perspectives about forests, and encourage a different management of forests across the world."

Research allows us to make informed decisions about how to manage the forests most effectively for wildlife and to best maintain the Earth's carbon balance and climate. It's currently thought that 40 percent of all species on Earth may exist in the forest canopy, but we don't yet know the value of this biodiversity. Pollination by species that use the canopy has been estimated to contribute US $12 billion to global agriculture and, compared to intact forest, heavily deforested areas show a 300-fold increase in the risk of malaria.

As described by Keith, Bruce met Alessandro Araujo, a micro-metrologist who is sampling levels of CO2 and O2 gases in the forest. Throughout the day and night Bruce and Alessandro sampled air at ground level, midway up the tree, and at canopy level. In order to do this they spent the night in hammocks at the top of a 45m Anjelim tree. Closed forest canopies are fragmenting and disappearing faster than any other habitat, so we need to obtain and use evidence to inform their management and protection before it is too late.

Bruce perches high in the canopy

Bruce perches high in the canopy.

Assellandro Araujo is a scientist researching the value of forest environments, obtaining facts vital to the management of the Amazon.


What's the solution?

In South America deforestation occurs mainly for large scale farming enterprises that provide beef and soya for export markets. This activity boosts the economy of countries and creates jobs for individuals, but at what cost? What impact would the loss of the Amazon rainforest have upon the atmosphere and upon global weather systems? Will deforestation be the biggest regret of future generations?

As an alternative, there could be economic incentives provided for forested countries to preserve and protect this important global resource. To this effect, Joseph Stiglitz (2005), a Nobel Laureate in Economics, states: "A huge mistake was made at Kyoto. While countries can be compensated for planting forest, they cannot be compensated for avoiding deforestations. Countries like Papua New Guinea would thus be doubly better off if they cut down their ancient hardwood trees and replanted. But this makes no sense economically or socially. These countries should be given incentives to maintain their forests."


Links

Global Issues: Carbon Sinks, Forests and Climate Change
A site publishing scientific evidence of links between deforestation and climate change.

UNFCCC: Kyoto Protocol
Explaining the provision and context of the Kyoto protocol, the international treaty on climate change.

The Encyclopedia of Earth: Large-Scale Biosphere-Atmosphere Experiment in Amazonia
Explaining the work of the LBA research centre, where Bruce met and worked with metrologist Alessandro Araujo.

Manaus research (PDF)
A poster by Alessandro Araujo and colleagues, showing their research in the rainforest near Manaus.

Oxford University: Climate change and the fate of the Amazon
A conference hosted by Oxford University Centre for the Environment (OUCE) about climate change and the fate of the Amazon. Available on the site are podcasts and lecture slides from speakers.

Mongabay: Is the Amazon more valuable for carbon offsets than cattle or soy?
A site discussing the possibilities of offering payment to nations in return for their maintenance of carbon reserves.

On the BBC:

BBC News: Amazon carbon sink effect 'slows'
The role of the Amazon rainforest as a carbon sink.

BBC News: Q&A: The Kyoto Protocol
Questions and answers about the Kyoto protocol.

BBC Weather Centre
Issues and facts about climate change.


References

Siegenthaler et al, (2005), Stable Carbon Cycle-Climate Relationship During the Late Pleistocene, Science 25 November 2005: Vol. 310. no. 5752, pp. 1313 - 1317

Malhi et al, (2002), Biogeochemical cycling of carbon, water, energy, trace gases, and aerosols in Amazonia: The LBA-EUSTACH experiments (PDF)

Parmesan, C, and G Yohe, (2003), A globally coherent fingerprint of climate change impacts across natural systems, Nature 421: pp37-42

IPCC, (2007), Fourth Assessment Report: Climate Change 2007 Full report (PDF)

Stiglitz, Joseph (2005), Cleaning Up Economic Growth


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