Black Carbon — Changing Planet

ANNE THOMPSON, reporting: It can be seen billowing from smoke stacks,
diesel engines and cooking stoves in villages and cities around the world. Black carbon,
small soot-like particles that are produced whenever fossil fuels or other organic substances
are incompletely burned. Dr. VEERABHADRAN RAMANATHAN (Scripps Institution
of Oceanography): One of the major sources of black carbon is indoor cooking with biomass
fuels, firewood, cow dung, crop residues, is a major source of fuel and amazingly roughly
half the worlds population, about three billion depend on these fuels. THOMPSON: According to the World Health Organization,
black carbon causes an estimated 1.5 million deaths per year due to respiratory ailments
and other diseases. But beyond the public health implications, black carbon also has
serious impacts on the environment. Dr. Veerabhadran Ramanathan at the Scripps
Institution of Oceanography in San Diego calls it one of the leading contributors to global
warming, after carbon dioxide. RAMANATHAN: The reason were thinking about
black carbon and we are worried about it is that its the most efficient absorber of sunlight,
thats why its blackish. THOMPSON: In the air, these tiny black carbon
particles absorb energy from the sun. This energy gets converted to thermal energy, which
warms the atmosphere. Inside his lab, Ramanathan compares black carbon samples gathered from
different regions of the world. RAMANATHAN: If you think thats dark, this
is that filter collected next to the cooking stove of a women cooking thats exactly what
she is breathing. THOMPSON: To track the concentration of black
carbon in the air and the amount of sunlight it absorbs, he also flies unmanned aerial
vehicles, or UAV’s, directly into polluted air. With this information, Ramanathan can
get a global picture of black carbon and how it spreads around the world, sometimes hundreds,
even thousands of miles from its source. RAMANATHAN: To my mind what this shows, each
one of us is in somebody elses backyard. So were not going to solve this problem by pointing
fingers. THOMPSON: But the problem doesn’t end there.
As these particles get knocked out of the atmosphere by falling rain or snow they accumulate
on mountaintops and glaciers, with additional negative impacts. Dr. JOE MCCONNELL (Desert Research Institute):
If you add just the tiniest amount of black carbon to that fresh snow, it will change
the amount of energy that it absorbs, cause it to warm more quickly and eventually melt
more quickly. THOMPSON: This process is called the ‘Albedo
Effect’. As the soot darkens the bright white snow covering glaciers and ice caps, it absorbs
solar energy, grows warmer and contributes to melting the ice cap causing it to shrink. Dr. Joe McConnell, studies this effect in
the seasonal snow pack in the Sierra Nevada Mountains in the western United States. By
measuring the temperature of the snow and the distribution of black carbon and other
particles in it, McConnell and his team can find out how much black carbon contributes
to snow melt. MCCONNELL: And theres our sample. THOMPSON: In the lab, McConnells research
goes even deeper. He studies ice cores that span decades, like this one collected from
Greenland. MCCONNELL: This particular section of ice
is about 130 years old, this is snow from the 1870s or so. THOMPSON: Using a special instrument for melting
ice cores, McConnell measures individual black carbon particles to find out how, and in some
cases where black carbon was produced decades ago. MCCONNELL: Right now were at about 1850, so
this is about 160 years ago this snow fell, so these bumps are primarily coming from forest
fires that happened 160 years ago. THOMPSON: With this data, McConnell supplies
global climate modelers with more accurate histories of black carbon and other emissions. MCCONNELL: This is the most recent decade,
2000-2010, and you can see most of the emissions are coming from this part of Asia. THOMPSON: But of all the causes of global
warming, black carbon might be the easiest problem to fix because, unlike carbon dioxide,
it stays in the atmosphere for only a short time. RAMANATHAN: The most appealing part of targeting
black carbon to reduce global warming is its lifetime. It stays in the air less than a
few weeks so what that means is that when you initiate a policy to condemn black carbon
today, theyre gone two weeks from now. THOMPSON: Ramanathan has started a program,
called Project Surya, distributing solar powered lanterns, and cleaner, more efficient cooking
stoves to families. One of his first test areas is a village in
the Uttar Pradesh region of northern India. His goal is to not only reduce global warming,
but also to create a more healthy environment for people who rely on these cooking stoves. RAMANATHAN: So Surya is a scientific intervention
project. Its also a demonstration to show that if these women could be given better
stoves, which cuts on emissions it not only helps them, it helps the region and helps
the planet. THOMPSON: Paving the way for a cleaner, brighter
and healthier future for the planet and its people.


Add a Comment

Your email address will not be published. Required fields are marked *