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AFUW-ACT
Inc. Meeting Report
Topic: CLIMATE CHANGE: FACT OR FICTION?
Speaker: Dr. Janette Lindesay
Dr Janette Lindesay is Associate Professor of Climatology in the Fenner
School of Environment and
Society at the Australian National University, and Deputy Director of
the ANU Climate Change Institute.
Her research interests centre on climate variability and change during
the last 150 years, characterising
the nature and degree of variability and investigating climate impacts.
Much of her research was focused
on large-scale drivers of rainfall variability and drought, including
the El Nino Southern Oscillation
phenomenon; on climate change impacts in areas such as bushfire science
and human health; and on
applications of Global Climate Models in the study of climate and its
impacts. She teaches undergraduate
and postgraduate courses in atmospheric science, climatology and climate
change science and policy at
ANU and is committed to public education and the communication of climate
change science to the
community.
TIPPING POINTS FOR CLIMATE CHANGE
Global change includes the direct modification by humans of terrestrial
ecosystems-
Changes include solar radiation, atmospheric composition, and changes
of the ocean. . The human population is 8
billion people and is rising at an exponential rate.
Land cover is changing - because of the big increase in land being domesticated
the balance of species and vegetation
is changing and some species are becoming extinct or have actually become
extinct and the number is increasing. The
atmosphere keeps the earth at a reasonable temperature. By increasing
the gases, warmth is increasing.
GLOBAL CHANGE includes but is not limited to climate change. There are
three components of global change
research -impacts, adaptations, mitigations. How will plants respond
to multiple and interacting changes in their
environment? For example Eucalypts become more frost sensitive in their
early life.
LANDSCAPES & GLOBAL CHANGE Direct modification of the landscape
is one of the most potent drivers of
global change which will cause significant changes.
INTERGOVERNMENTAL PANEL is a process open to all scientists and provides
the opportunity to debate current
issues with a wide cross section of peers. There is new and stronger
evidence that most of the warming is due to
human activity. Scientists have high understanding of gases but not
much of the other factors. A 20% decrease in
rainfall is significant, as are the number of days it rains. CO2 concentration
in the atmosphere has remained within
tight bounds, but already it has changed after more than 400,000 years.
Northern Hemisphere records go back 1000
years; it was cooler then, it is now higher than in the last 1000 years;
it is outside the range of the past.
HOW DO WE KNOW IT IS US? In the high latitudes there is a 4% increase
with the sea ice melting in the North Sea
from which there are many ramifications. In Australia the temperatures
began to warm up after 1960. The causes are
population growth, land degradation, invasive species and fragmentation.
WHAT ARE OUR OPTIONS?
We need to understand the carbon cycle - 99.95% carbon is locked up
in rocks and is recycled very slowly over
geological time. The remaining .05% cycles much faster.
In the global carbon cycle, carbon is stored in fossil deposition and
in plants and soil.
The Biosphere acts as a sink because the plants take up the carbon,
as does the ocean.
WHERE CAN WE STEP IN?
Through land management by stopping land clearing. Energy and industry
put most carbon into the atmosphere, beef
cattle add 60 kg. a year, through regurgitation when chewing their cud.
Energy generated per person in Australia is
considerable.
Carbon sinks and the initiatives agreed and implemented in following
the Kyoto protocol will help reduce the global
carbon cycle. A forest carbon sink takes much carbon into the soil.
Saltbush is a form of carbon sink. From the middle
of the Century it wil
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