Download Environmental concerns:

Environmental concerns:
1. The thinning of the ozone layer;
2. Global warming:
 signals
 causes
 consequences
 political action
In the past three decades it has been scientifically documented that the planet is facing an
unprecedented situation as a result of the increasing scale and cumulative effect of human
activity.
The impacts are worldwide and include
the thinning of the ozone layer, and
climate change (global warming),
This has highlighted the increasing ecological interdependence among countries.
Slide
The ozone layer
In the 1970s scientists discovered that the use of chlorofluorocarbons (CFC)
 group of chemical compounds used in refrigerators , aerosol sprays , and foam
packaging that destroy ozone molecules –
threatens the ozone layer shielding the surface of our planet from the full force of the sun’s
ultraviolet radiation (cancer, algae).
http://www.nasa.gov/vision/earth/lookingatearth/25TOMSAGU.html
The threat was especially acute to the world’s southernmost cities,
since a large hole in the ozone was found to be opening up each year over Antarctica,
but in the long run, the entire ozone shield was imperiled.
Once the scientific evidence became overwhelming (and frightening enough to generate political
pressure), governments and industry worked together to reduce the ozone “hole”
international action followed relatively rapidly with the signing of the Montreal Protocol in 1985.
The developed countries phased out virtually all use of CFCs by 1999, and the developing
countries (given a ten years grace period) are now moving toward the same goal.
Still: In Punta Arenas, residents have to cope with radiation alerts when ozone depletion is so
severe that it becomes highly dangerous to expose skin or eyes to the sun.
Slide
The Montreal protocol: many people hailed it as an example that could inspire those who
are trying to combat climate change.
But: Climate change is a different story.
Global warming:




signals
causes
consequences
political action
The world’s total meat supply was 71 million tons in 1961.
In 2007, it was estimated to be 284 million tons.
Per capita consumption has more than doubled over that period. (In the developing world, it rose
twice as fast, doubling in the last 20 years.)
World meat consumption is expected to double again by 2050, which one expert, Henning
Steinfeld of the United Nations, says is resulting in a “relentless growth in livestock
production.”
Americans eat about the same amount of meat as we have for some time, about eight ounces a
day, roughly twice the global average.
At about 5 percent of the world’s population, we “process” (that is, grow and kill) nearly 10
billion animals a year,
more than 15 percent of the world’s total.
Raising animals in factory farms uses many different resources.
An estimated 30 percent of the earth’s ice-free land is directly or indirectly involved in livestock
production, according to the United Nation’s Food and Agriculture Organization.
Livestock production generates nearly a fifth of the world’s greenhouse gases — more than
transportation.
If Americans were to reduce meat consumption by just 20 percent it would be as if we all switched
from Toyota Camry (30) to Toyota Prius (60).
A recent study by the National Institute of Livestock and Grassland Science in Japan estimated
that 2.2 pounds of beef is responsible for the equivalent amount of carbon dioxide emitted
by the average European car every 155 miles, and burns enough energy to light a 100-watt bulb
for nearly 20 days.
Slide
Undisputed Signals: (What has been observed?)
Our planet has shown clear signs of warming over the past century.
2. The 1990s were the hottest decade, and 1998 the hottest year, (2001 the second hottest)
recorded over the 140 years for which records have been kept.
2005
In fact nine of the ten hottest years during this period have occurred since 1990, and
temperatures are now rising at three times of the early 1900s.
In 2006, the average temperature in central England was the highest ever recorded since the
Central England Temperature (C.E.T.) series began in 1659.
(Estimates of earlier temperatures made from data such as
ice cores and tree rings, though not as reliable as thermometers, suggest the decade may have
been the warmest in the past millennium).
4. the Arctic, shows signs of rapid warming.
Temperatures in the Arctic are rising roughly twice as fast as the global average.
A report published in 2005 as part of the Arctic Climate Impact Assessment, which synthesized the
work of 300 researchers,
showed that the amount of sea ice has fallen by 8% in the past 30 years, and also found
signs that Greenland’s ice cap is melting more rapidly than in the past.
The Greenland ice cap shrank by 50 cubic miles in 2005 only.
Arctic sea-ice is melting away at a rate of around 9% a decade. It used to be thought that
there would be no sea-ice in summer months by 2060.
Newer calculations have brought that date forward to 2040.
The North Pole could be swirling in ice-free seas in summer by 2040.
What about Antarctica, which along with Greenland forms one of the principal stores of
fresh water on earth?
The southern polar region seems a bit more stable.
Most of the southern continent's icy mass, especially the eastern half which rests on some
very solid rock, is so deep-frozen that so far at least, it has been impervious to climate
change.
Encircled by icy winds, the compacted snow of Antarctica's deep interior is actually
growing in volume.
If all the water locked up in Antarctica were to cascade into the ocean, global sea levels could rise
by 60 metres (185 feet), leaving more than a third of the UN's New York headquarters under water.
But: two parts of Antarctica are heating up rapidly.
The peninsula that sticks out of the continent has warmed three degrees Centigrade in the past 50
years.
In Pine Island Bay two giant glaciers are shrinking, and this process is accelerating.
Scientists report that 212 of the 244 glaciers necklacing the Antarctic Peninsula have
retreated as temperatures have risen more than 4.5 degree F in the past 60 years.
Punta Arenas: dozens of glorious glaciers, almost all of them (87% by one recent estimate)
retreating and thinning. The nearer they are to the sea, the more vulnerable they are to rising
temperatures.
Some time in the coming decades, the shrinking of glaciers will cause a drop in the level of
glacial runoff, reducing the supply of water to urban Chileans.
A similar challenge faces more than 1 billion people (living in urban areas) in other parts of
the world who rely on glacial runoff for their water.
All over the world, species are edging towards the poles as their habitats change.
But Arctic and Antarctic creatures have nowhere colder to go. Pity the polar bears. They depend
on sea-ice to hunt seals.
The less sea-ice there is, the fewer seals there are to eat.
That, presumably, is why the only long-term study of a polar-bear population, from Hudson Bay, in
Manitoba in Canada, suggests that the average bear is 15% thinner than he was 30 years ago.
5. There used to be a disagreement over the temperature trend on the ground, which
appeared to be rising, and that further up in the atmosphere, which did not.
Now, both are known to be rising in parallel.
6. The Scripps Institution of Oceanography (California) has been following changes in the way the
world’s oceans have warmed up at different depths over the past 65 years.
7. The increasing evidence demonstrates the link between increased sea-surface
temperatures and the frequency of the most intense categories of hurricane, typhoon and
tropical storm.
8. An observation that ocean currents in the North Atlantic are faltering (are not being steady)
in ways that computer models of the climate previously suggested would happen in
response to increased temperatures.
In addition:
-- IN the past three decades the El Nino effect in the southern hemisphere has become intense,
causing greater variation in rainfall.
-- Since the 1960s snow and ice cover has decreased by about 10 percent, and mountain
glaciers are in retreat everywhere, even near the poles.
The glaciers vanish at the bottom of Patagonia, Tibet, Kilimanjaro, the Alps.
The signals, in other words, look strong.
Disturbing. But how do we know what causes this?
Slide:
Consequences:
 The IPCC report estimates that between 1990 and 2100 average global temperatures will
rise by at least 1.4 C (2.5F) and perhaps by as much as 5.8C (10.4F).
(The fourth) report warns that if society keeps to its current course, emissions will increase to
twice their preindustrial levels by the end of this century, causing temperatures to rise 3.5 to 8
degrees.
Although these average figures may seem quite small, even a 1C rise in average
temperatures would be greater than any change that has occurred in a single century for
the past 10,000 years.
-- If global warming isn’t halted, devastating sea-level rises will be inevitable by 2100.
IPCC predicted that sea levels could rise as much as three feet by 2100 (that is, in less than 100
years).
-
The last time the earth was that warm, see levels were 80 feet higher than today. It
will likely take hundreds of years for sea levels to rise full 80 feet, but the process would be
irreversible, and the rises would not be gradual.
-- As sea levels continue to rise millions of people may be affected in China, Egypt on the Nile
delta.
-- As sea levels continue to rise millions of people may be affected in China, Egypt on the Nile
delta.
http://www.photoglobe.info/spc_nile_delta.html
-- Since roughly half the world’s 6.5 billion people live near coastlines, a three-foot sea-level rise
would be punishing in places like Amsterdam, Venice, Cairo, Shanghai, Manila, and Calcutta.
The WHO estimates that climate change is already helping to kill 150,000 people a year,
mainly in Africa and Asia. That number is likely to go up as global warming intensifies in the
years ahead.
-- In many places the people and governments are too poor to erect adequate barriers.
-- Bangladesh’s 145m people live on a delta twice the size of Ireland, 40% of which is flooded for
three months of each year. It is desperately overcrowded.
By 2050, its population is projected to reach 250m.
Around 1% of agricultural land is lost to river erosion each year.
An estimated 18 million people are at risk. (in 1991 a cyclone hit the coast of Bangladesh,
coinciding with high tides that left 10 million people homeless and killed 139,000).
-- So experts fear that they will migrate to neighboring lands, raising the prospect of armed conflict.
On a smaller scale, Pacific island nations that consist of low-lying atolls face even more
drastic losses (Kiribati west of the international date line) High tides are already causing erosion
and polluting fragile sources of fresh water, and some uninhabited islands have been submerged.
-- -- Global warming would lead to an increase in summer deaths (heat stress).
Global warming would bring heat waves like the one in the summer of 2003 that killed 31,000
people across Europe.
 Northern landmasses, especially North America and Central Asia, will increase overall, but
there will be sharp regional variations.
-- Some regional changes will be more extreme and are much more difficult to predict.
-- There will be greater year-to—year fluctuations than at present –which means that droughts an
floods will increase.
-- The Asian summer monsoon is likely to become less predictable.
Hundreds of millions of peasant farmers in India and other countries will go hungry in the
years in which the monsoon bring less rain than normal. They have no other way of obtaining
the water needed for growing their crops.
India: there monsoon is a fact of life that they have developed their agricultural economy
around.
If the monsoon is down by 10 percent one year, they have massive loses of crops.
If it’s 10 percent over they have massive flood problems. If climate change ends up switching
off the monsoon in India, or even changing it outside those limits, it would lead to massive global
economic de-stabilization.
No one can say for sure whether global warming caused hurricane Katrina, which slammed
into the Gulf Coast on August 29, 2005. But it fits the pattern.
Most scientists agree that global warming makes extra-strong hurricanes such as Katrina more
likely because it encourages hot oceans, a precondition of hurricane formation. Hurricanes
had grown more powerful as global temperatures rose in the 20th century.
Katrina was the perfect preview of what global warming might look like in the 21 st century. Katrina
was a category 5 hurricane, the strongest there is. It unleashed 10 to 15 feet of water on a city that
was already significantly below sea level.
-- tropical diseases will become more widespread (including diseases carried by insects that
need warmth to survive (malaria, dengue).
-- food production will rise in the high northern latitude and fall in others, including sub-Saharan
Africa.
-- Sever consequences for non-human animals and for biodiversity. Australia’s unique alpine plants
and animals already survive only on the country’s highest alpine plains and peaks.
-- Coastal ecosystems. Warmer waters may destroy coral reefs.
Slide
Maybe this is just part of some kind of a larger natural process?
explained by natural variation?
Paralleling these changes is:
an unprecedented increase in concentrations of carbon dioxide, methane, and nitrous oxide
in the atmposhere,
produced by human activities such as burning fossil fuels.
The scientific study: there are still some uncertainties.
1. Some researchers look at the data and agree they show a warming trend. But they argue
that this may be caused not by man but by nature, in the form of small increases in
the sun’s heat output.
That output is known to vary during the course of the 11-year sunspot cycle, as well as over
the longer term.
Although such changes have not been matched to temperature changes in the way that rises
in the level of greenhouse gases have been,
they may still be making a contribution.
2. Another issue is that a second type of pollutant, aerosols such as the tiny little
sulphate particles that form when sulphurous fuel is burned, promote the formation of
clouds. These reflect sunlight away from Earth and thus oppose the effect of greenhouse
gases.
Some have seen this as a possible counterbalance and, indeed, such “dimming” has been noticed
in several parts of the world.
3. Perhaps the most important uncertainty, though, is that caused by a lack of enough
good-quality, long-term, internally consistent data.
Even the industrialized parts of the world, Europe and North America and their adjacent
seas, have been well studied for only a century and a half.
This leads some to believe that too much climate science relies on drawing
conclusions from patchy information.
Climate change:
Human induced with certainty?
Slide
Climate change entered the international political arena in 1988, when the UN Environment
Program and the World Meteorological Office jointly set up the Intergovernmental Panel on
Climate Change, (IPCC)
an international scientific body
sponsored by the UN,
a peer-reviewed, international collaboration among thousand of scientists.
It is the world’s leading authority on climate change,
created to provide policymakers with an authoritative view of climate change and its
causes.
In 1990, the IPCC reported that the threat of climate change was real, and that a global treaty was
needed to deal with it.
In 1990, the IPCC reported that the threat of climate change was real, and that a global treaty was
needed to deal with it.
The UN General Assembly resolved to proceed with such a treaty.
1992: The UN agreed on the Framework Convention on Climate Change that opened for signature
at the Earth Summit in Rio de Janeiro.
This framework convention was accepted by nearly all the world's countries 181 governments),
including the United States.
It is no more than a framework for further action.
It called for greenhouse gases to be
stabilized at safe levels,
but included no binding targets and never defined an unacceptably dangerous concentration of
greenhouse gases.
The developed nations committed themselves to 1990 levels of emissions by 2000, but this
commitment was not legally binding. (This framework convention did not set any emission
reduction targets.)
As a result, the US and others did not pay attention. By 2000 carbon dioxide emissions were 14
percent higher than they were in 1990.
In 1995, this conference decided that more binding targets were needed.
The result, after two years of negotiations, was the 1997 Kyoto Protocol, which set targets for
39 developed nations to limit or reduce their greenhouse gas emissions by 2012.
The limits and reductions were designed to reduce total emission from the developed nations to a
level at least 5 percent below 1990 levels.
The national targets vary:
For example:
the EU’s target was 8 percent below 1990 levels
the US target was 7 percent below 1990 levels,
and other nations, such as Australia, being allowed to go over their 1990 levels.
The Kyoto pact does impose mandatory limits on industrialized nations, but they do not
apply to developing nations, including China and India.
The targets were arrived through negotiations with government leaders, and they were not based
on any general principle of fairness,
To assist countries in reaching their targets, the Kyoto Protocol accepted the principles of
“emission trading” by which one country can buy emissions credits from another country that
can reach its target with something to spare.
The Kyoto conference did not settle the details:
For example:
how countries could meet their targets,
how emission trading was to operate
and whether they would be allowed credits for planting forests that soak up carbon dioxide
from the atmosphere.
Key points in the debate on climate change:
1. Dangerous levels of greenhouse gas with well-known consequences (rising temperatures
threatening flora and fauna, melting of ice caps, rising sea-levels).
2. Problem: Unequal distribution of negative effects.
Russian ports.
New waterways in Canada.
But:
If the sea levels go up 30 feet ¼ of the land will go under water.
Floating libraries
Floating schools
Bangladesh (167 million people) as big as Wisconsin (5 million people).
Why is this a problem? Why should Russians or Canadians join efforts to reduce greenhouse gas
emissions?
Up to 90 percent of humanity doesn’t have the resources to deal with climate change.
3. We need to limit greenhouse gas emissions.
4. But if we do that we may stifle economic growth.
A billion of people in Asia, Africa, and South America strive to ascend from poverty.
China and India continue to insist that economic growth is both their priority and right.
Developing countries repeatedly made that point in Bangkok (April 2008) in the latest round of
United Nations talks over the shape of a new climate agreement.
China, India and other developing nations march headlong into the modern world of cars and
electric consumption on their way to becoming the dominant producer of greenhouse gases for
decades to come.
China is building, on average, one large coal-burning power plant a week.
5. So how do we do reduce greenhouse gas emission without stifling economic growth (particularly
in the developing countries)?
We need technologies to do both: reduce CO2 emissions and expand global economy.
We need radically advanced low carbon technologies.
US and China should play a leading role.
IPCCs Third Assessment Report in 2001 (122 lead authors + 515 contributing authors).
IPCCs Fourth Assessment Report in 2007
Open to criticism by other scientists but it reflects a broad consensus of leading scientific opinion
and is by far the most authoritative view at present available on what is happening to our climate.
There is an ongoing effort to produce a new international climate-change treaty to supplant the
Kyoto Protocol, which expires in 2012.
A new agreement is supposed to be finished and ready to be signed in Copenhagen at the
end of 2009 (the Copenhagen process).