I was a skeptic; I didn't
believe a word of it. Climate change was just the latest trend in scientific
research and people in white lab coats were scrambling to get on the ‘gravy
train’ before someone came along and burst the bubble.
Talk of climate change has
been in the air for nearly two decades and has raised enormous concern and
considerable debate in our information society. Opinion polls showed that there
was a peak of support in 2008 followed by a fall in 2010. In fact opinion has
moved up and down like the mercury in our thermometers.
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As the oceans warm, storms become much more violent.
According to a survey
released in January, 2010 by Yale and George Mason Universities, only about
50percent of Americans were concerned about global warming, less than 50
percent thought humans contributed to it, and more than 43 percent didn’t
believe it was happening at all.
In another study published by Yale University
in October, 2010 only 57 percent of Americans knew what greenhouse gases are
and only half knew they were produced mostly through human activity.
Incredibly, 75 percent had never heard of ocean acidification or coral
bleaching. It seems strange then that the general population was still in the
dark.
Is it really happening?
By June, 2010 Science published the first
comprehensive synthesis of climate change studies dealing with the ocean. The
startling results were that the rates of change in man-made atmospheric green
house gases were driving irreversible and dramatic changes in the way the ocean
worked.
Prof. Hoegh-Guldberg,
Director of The University of Queensland’s Global Change Institute, predicted
dire impacts on hundreds of millions of people around the globe.
"Although
there remains active discussion among scientists on many details about the pace
and effects of climate change, no leading science organization disagrees that
human activities are now changing the Earth's climate. The strong scientific
agreement on this point contrasts with the partisan disagreement seen on all of
our surveys," said Lawrence Hamilton, professor of sociology and senior
fellow with the UNH Carsey Institute.
So
what is global warming?
The greenhouse
effect was discovered
in 1860 by John Tyndall. Since the early 20th century, the average temperature of the
Earth has increased about 0.8oC and most of this has happened since
1980. In statistical terms we are about 95 percent sure that the warming is
from greenhouse gases from burning fossil fuel and cutting forests. The biggest
contributors are electricity, industry, and transport (adding up to about 54
percent). This idea is now accepted by the national science organisations of
all major industrialized countries.
Greenhouse
gases, principally carbon dioxide, absorb heat from the sun and raise the
temperature of the atmosphere and ocean. Carbon dioxide has increased by an
unbelievable 24 percent in the last 50 years and from polar ice cores we know
it is now higher than any time in the last 800 thousand years and
probably in the last 20 million years. Carbon dioxide is
expected to reach over 900 parts per million during this century which is an
incredible increase of 250 percent since we started burning fossil fuels.
The Fourth Assessment Report (AR4) by the Intergovernmental
Panel on Climate Change (IPCC, 2007)
indicated that during the 21st century the global surface temperature is likely
to rise a further 1.1 to 2.9 °C for their lowest emissions scenario and 2.4 to 6.4 °C for their highest. Because water easily
absorbs heat, 93.4 percent of global warming affects the ocean.
These may seem like tiny increases but in
fact they are disastrously large. Even small changes in temperature may cause
big changes in the climate. We can expect an expansion of deserts and much less
rain in parts of the tropics. Melting of the ice caps will change ocean
circulation and seafood production. There will be unprecedented extinctions of
wildlife on a global scale.
The impact of global warming is easily seen in these satellite photos of the Arctic.
This all sounds pretty awful but to many
people it is seen as just another inconvenience. Life will go on with ‘business
as usual’. Flooding of the major cities by the end of the century; I’ll be dead
by then!
The problem is that an awful lot of people
may be dead a lot sooner and it won’t be business as usual at all.
Where is it going to ‘hurt’ the most?
It is estimated
that a global rise in temperature of only 1.5-2 °C will
bring about the catastrophic extinction of many of the Earth’s species. We
aren’t just talking about species we don’t ‘need’ or don’t ‘like’. In one study published in Nature in 2004, between 15 and 37% of 1103
endemic or near-endemic known plant and animal species will be "committed
to extinction" by 2050.
But
climate change is only starting. Global warming will catapult the Earth and our
society into entirely new situations with new rules. Even a 2 °C rise
above the pre-industrial level will be outside the range of temperatures
experienced by human civilization.
In
the tropical seas coral reefs and their fisheries simply will not survive the
temperature rise. Coral bleaching, which kills coral, occurs with rises of as
little as 1 °C above the summer maximum. Without corals the food web of
reefs and the populations of people who depend on them will collapse.
Coral bleaching happens when corals expel their food producing algae. Starvation is the result.
Coral reefs are
already the world’s most endangered ecosystem supporting 25 percent of the
ocean’s species. The collapse of these incredibly complex “islands of life”
will send not a ripple but a ‘tsunami of change’ through the oceans of the
world and through Coral Triangle and Pacific Island communities where some 200
million people are sustained by tropical fisheries.
The
situation may be even worse in the open ocean where tiny drifting creatures
like sea butterflies and planktonic animals and plants grow thin calcium shells
over their fragile bodies. Even if they cope with the rising temperature, the
increased carbon dioxide produces a weak acid in seawater that dissolves their
shells and kills them.
The fragile sea butterfly is an important food for most of the world's fisheries.
These
frail creatures exist in the trillions and are the food of all the commercial
fisheries and most whales. Scientists say that most of these tiny species will
be lost by 2065. Between
now and then there will be huge disruptions of the ecological food web as species
begin to drop out. From about 2065 on we can expect the rapid and catastrophic
collapse of most commercial fisheries. The ocean ecosystem will simply fail.
In June, 2010 Science magazine we find that the oceans
are now changing at a rate not seen for millions of years. "We are entering a period in
which the very ocean services upon which humanity depends are undergoing
massive change and in some cases beginning to fail," says Prof.
Hoegh-Guldberg. "Further degradation will continue to create enormous
challenges and costs for societies worldwide."
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The loss of Arctic ice is now so fast that many scientists believe it can not be reversed.
What will happen to us
as the earth grows warmer?
UNESCO
predicts that 100-150 million people in S.E. Asia alone will be displaced
through shoreline erosion, rising sea level, drought, and food shortages by
2050.
Approximately 40% of the world's
agricultural land was already seriously degraded in 2007. If current trends of soil degradation
continue as they are in Africa, underdeveloped countries might be able to feed
just 25% of their population by 2025 (based on UNU's Ghana-based Institute for Natural Resources in Africa).
Africa, small islands,
and Asian mega-deltas are regions that are likely to be
badly affected. Rainfall in much of S.E. Asia will be very much less and many
areas will become much drier or deserts including Indonesia, Malaysia, and
Borneo.
This
may seem like an inconvenience to some but to people living in agricultural and
subsistence economies throughout the tropics this is bad news. The impact of
global warming will be disproportionately large for disadvantaged communities
where resources, food, and health are already problems (Environmental
Justice, Dec. 2009).
"We
are becoming increasingly certain that the world's marine ecosystems are
approaching tipping points. These tipping points are where change accelerates
and causes unrelated impacts on other systems, the results of which we really
have no power or model to foresee."
Prof.
Hoegh-Guldberg concludes: "These challenges
underscore the urgency with which world leaders must act to limit further
growth of greenhouse gases and thereby reduce the risk of these events
occurring. Ignoring the science is not an option."
I am not alone in my belief that we are on
the brink of environmental catastrophe and have been joined in my concerns by
155 senior marine scientists from 26 countries who
recently signed the Monaco Declaration (The Royal Society, 6 July 2009), highlighting the twin threat of
growing ocean acidification and global warming.
It took me most of my childhood to be able to
admit mistakes and say “I did it”. Looking back at the way we have lived and
wasted the resources of this world we have to admit it is our fault; there is
no doubt; we did it. The question now is will we accept responsibility for
repairing the damage. Time is running out.
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If you are interested in some of the latest topics in ocean conservation check out some of the other posts on this site.
