Environment Forum
Global environmental challenges
Amazon’s drought, seen from space
How green is the Amazon?
Not as green as it used to be, as shown in an analysis of satellite images made during last year’s record-breaking drought.
Because greenness is an indication of health in the Amazon, a decline in this measurement means this vast area is getting less healthy — bad news for biodiversity and some native peoples in the region.
What does a drop in the greenness index look like? It looks gold, orange and red in a graphic accompanying an article to be published in the journal Geophysical Research Letters:
Gray areas are the norm, based on a decade of satellite observations that cover every acre (actually every square kilometer) on the planet. Dots that are gold, orange or deep red show areas with a decrease in greenness. Scientists call this the Normalized Difference Vegetation Index (NDVI on this chart) or the greenness index.
The chart shows what happened during July, August and September of 2010, the height of the dry season — a deep loss of greenness. The researchers found that the 2010 drought reduced the greenness of approximately 965,000 square miles (2.5 million square kilometers) of vegetation in the Amazon, more than four times the area affected by the last severe drought in 2005.
Even when rains came in late October, greenness didn’t bounce back, according to Ranga Myneni, one of the scientists who worked on this research.
Can farms and forests mix?
Forests and farms don’t mix, according to conventional wisdom.
Farmers are often portrayed as the villains, slashing and burning trees to clear land for crops and wrecking forests from the Amazon to Indonesia (…not to mention Europe, where people cleared most forests thousands of years ago).
But a report today by the World Agroforestry Centre indicates that farms aren’t such enemies of trees as usually thought - it says tree canopies cover at least 10 percent of almost half the world’s farmland. That is a gigantic area the size of China, or Canada. (For a story, click here).
Ten percent doesn’t sound much but one common definition of a “forest” by the U.N.s’ Food and Agriculture Organisation is an area where tree canopies cover at least 10 percent. It excludes farmland or urban areas (– otherwise your local supermarket car park might qualify if it’s got a few trees dotted around the tarmac).
Farmers sometimes keep trees as a backup if their main crops fail — with their deeper roots, trees producing fruit or nuts, for instance, can withstand droughts or floods better than many crops. Farmers also keep trees for uses such as a source of building materials, medicines or shade.
So trees are more common on farms than thought — and a home to a wider variety of insects or animals than a swathe of grassland, maize or wheat. They may also be a bigger store of the greenhouse gas carbon dioxide than expected, with a role in limiting global warming.
So have farmers got too bad a rap for deforestation?
in china and almost all east asian countries are farms and forests mixed. since more than 50% of the population from asia are still living in the village, so, the environmental problem are not that heavy.
Peru clashes raise green issues
Clashes in the Amazon between indigenous protestors and Peru’s army that killed some 60 people last week throw some old issues into sharp new relief: development versus the environment and local versus foreign control of natural resources.
Indigenous tribes, worried they will lose control over natural resources, have protested since April seeking to force Peru’s Congress to repeal new laws that encourage foreign mining and energy companies to invest billions of dollars in huge tracts of pristine rain forest.
In the developing world, extractive industries have a bad record of bringing benefits to local people. Prime examples include the oil-rich Niger Delta in Nigeria and mineral-rich South Africa under apartheid.
Equally bad is their record on the environment. The despoiled Niger Delta also springs immediately to mind (and it is probably no coincidence that it has also been wracked by conflict and insurgency).
The tensions in Peru also highlight the on-going debate about the environment versus development — especially when that development involves the planet’s dwindling rain forests.
A seven-year economic boom has failed to significantly reduce poverty in Peru, which is where about 36 percent of the population remains mired.
Those governments only see the forests as something standing in their way to the real big money. The real prize is the sale of mining concessions of the valuable resources that lie underneath.
The Amazon, the Pyramid and the Eiffel Tower
The Amazon rainforest lost trees and plants in a 2005 drought – shedding carbon equivalent to the weight of 140,000 Eiffel Towers or almost 200 Great Pyramids of Giza.
The drought, one of the worst in the past century, revealed the forest’s unexpected vulnerability to shifting rainfall and a huge role in releasing greenhouse gases – compounding problems such as logging and land clearance to create farmland.
The study in today’s edition of the journal Science (see story here) showed that the forest lost the equivalent of the annual carbon emissions of Europe and Japan during the drought — that’s five billion tonnes of carbon dioxide, or 1.4 billion tonnes of carbon stored in vegetation. The drought killed off some trees and slowed growth of other vegetation.
The Great Pyramid weighs perhaps 7.5 million tonnes, the Eiffel Tower 10,000.
The lead scientist of the study, Oliver Phillips of Leeds University, said that one answer could be for governments to consider even deeper cuts in their industrial emissions: the drought shows that people can’t rely on tropical forests to soak up emissions as the Amazon has been at least since the 1980s, a period of good growth ( … at least away from areas being burnt and chopped down).
So what can the world do? Among ideas: plant a tree in your back yard? Give tropical countries more incentives to safeguard the carbon stored in forests?
Deregulated industrialism kills the Globe constantly. When the developed countries start setting rules after having busted their eco sytem, all the multi-national companies are out sourcing their manufacturing part to the developing nations where you still get either leaner rules or corrupted system .. Getting the message acrossed at all levels, is the impossible task for the policy makers ..
All of this destruction in order to provide for modern industrial and economic might. Only humans can keep the forest from drying up by moving away from fossil fuels if it is not already too late. There is no such thing as clean coal, just look at the destruction to Kingston Tennessee from the compromised fly ash slurry containment. Geo-thermal holds the best promise for the future. Still man must also chart a path of population control and conservation.